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Groundwater Modeling System TUTORIALS Volume I GMS version 5.0

1. Figure 4 11 HUF Data The HUF package allows the stratigraphy to be specified in a grid independent manner We will now create HUF data from boreholes and horizons First we will need to create a 3D grid In this case we will read in a previously defined 3D grid 4 9 1 Reading the 3D Grid 1 Select the Edit Delete All command to delete all of the solid data 3 2 Switch to Plan View tox 3 Select the Open button Pd 4 Locate and open the directory entitled tutfiles horizons 5 Change the Files of type selection to All Files 6 Select the file entitled grid 3dg and select Open Stratigraphy Modeling Horizons And Solids 4 17 4 9 2 Initializing MODFLOW 2000 and HUF Data We are now ready to initialize MODFLOW and select HUF as our flow package 1 Switch to the 3D Grid module P 2 Select the MODFLOW New Simulation command 3 Select the Packages button in the current MODFLOW Global Basic Package dialog 4 In the Flow Package section of the dialog change the selection to Hydrogeologic Unit Flow HUF 5 Select OK to exit the packages dialog 6 Select OK to exit the MODFLOW Global Basic Package 4 9 3 Horizons to HUF Now we will convert the horizons data in the borehole module to HUF data 1 Switch to the Borehole module 2 Select the Boreholes Horizons gt HUF command 3 Select the Adjust Grid Elevations button 4 Turn on the Adjust grid cell elevations toggle and sele
2. Begin creating a cross section by single clicking on hole 1G then single click on holes 7G 2G 5G and 6G in that order Finish creating the cross section by double clicking on hole 8G Create another cross section by single clicking on holes 3G and 6G and then double clicking on hole 7G Create the final cross section by single clicking on hole 4G and double clicking on hole 5G ll now view the solid cross sections that we just created Switch to the Borehole module Select the Select Cross Section tool AA Select the Edit Select All command Select the Hide button my Switch to the Solids module A In the Data Tree select the check box next to the Solid Data folder to hide all of the solids Switch to Oblique View tz Select the Data Cross Section Options command Turn on the Cross section faces and select OK 4 16 GMS Tutorials Volume I You should now see the cross sections we created from the solids The solid cross sections should look very similar to the borehole cross sections 4 9 Creating HUF Data From Horizons The Hydrogeologic Unit Flow HUF package is new in MODFLOW 2000 The HUF package is used to define the hydraulic characteristics hydraulic conductivity storage coefficients of each grid cell in the MODFLOW simulation The HUF package can be used in place of the BCF or the LPF package in MODFLOW 2000 The figure below shows an example of HUF data ina MODFLOW grid
3. 3 8 Building Cross Sections 1G 7G and 4G 5G Next we will build cross sections 1G 7G and 4G 5G Since the two boreholes in each of these two cross sections partially match each other in the sequence of borehole regions we will still use the Automatch command to automatically create arcs connecting the matching borehole contacts However we will have to manually create the other arcs needed to delineate the soil layers Then we will use the Build command to build the polygons representing soil layers 3 8 1 Building Cross Section 1G 7G 1 Double click on 1G 7G s icon to bring up the Cross Section Editor 2 Select the Automatch button 3 Select the Create Arc tool E Figure 3 2 Cross Section 1G 7G 3 6 GMS Tutorials Volume I 4 Click on the node corresponding to the blue red contact blue on top red underneath on hole 7G to begin double click on the node corresponding to the bottom of hole 1G to end 5 Select the Build button 6 Select the OK button 3 8 2 Building Cross Section 4G 5G 1 Double click on 4G 5G s icon to bring up the Cross Section Editor 2 Select the Automatch button 3 Select the Create Arc tool i 4G 5G Figure 3 3 Cross Section 4G 5G 4 Click on the node corresponding to the lower blue red contact on the hole 5G to begin double click on the node corresponding to the bottom of hole 4G to end 5 Select the Build button 6 Select the OK button 3 9 Building C
4. When you are finished close the window and return to GMS 8 19 Conclusion This concludes the 3D Geostatistics tutorial Here are some of the key concepts in this tutorial There are several 3D interpolation algorithms available in GMS Mesh centered grids are better than cell centered grids if you are just doing interpolation and not using MODFLOW Iso surfaces can be used to visualize the results of an interpolation 8 12 GMS Tutorials Volume I e Vertical anisotropy can be used to help overcome the problem of grouping that is common with data collected from boreholes CHAPTER 9 Generating MODFLOW Data From Solids Complex stratigraphy can be difficult to simulate in MODFLOW models MODFLOW uses a structured grid that requires that each grid layer be continuous throughout the model domain This makes it difficult to explicitly represent common features such as pinchouts and embedded seams in a MODFLOW model Solid models can be used to represent arbitrarily complex stratigraphy Figure 9 1 shows a cross section through a solid model where different stratigraphic units pinchout Designing a MODFLOW compatible grid for this type of stratigraphy is very difficult 9 2 GMS Tutorials Volume I Figure 9 1 Cross section through a Solid Model In this tutorial we will cover the steps necessary to convert solid models like the one in Figure 9 1 to MODFLOW data The elevations associated with the
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6. entire grid depth for each grid column is distributed according to the entries in the spreadsheet for each layer 6 In the Elevation bias spreadsheet change the value for layer 1 to 0 4 7 Select OK to execute the Solids gt HUF command 9 10 3 Viewing the HUF Data To view the HUF data 1 Switch to the 3D Grid module YH 2 Select the Display Options button a 3 Switch to the MODFLOW tab 4 Turn on the Display hydrogeologic units toggle 5 Select OK to exit the dialog 6 Select the Select Cells tool qe 7 Select a cell somewhere near the middle of the grid 8 Select the View J Axis button g 9 Use the arrow buttons Y A to view the grid along different rows Generating MODFLOW Data From Solids 9 15 9 10 4 Converting the Conceptual Model We need to convert the conceptual model again to ensure that any cells that were inactive will have the correct boundary conditions N 1 Switch to the Map module 2 Switch to plan view by selecting the View K Axis button 3 Select the Feature Objects Map gt MODFLOW command 4 Ensure the All applicable coverages option is selected and select OK 9 10 5 Running MODFLOW We re now ready to save the project and run MODFLOW 1 Switch to the 3D Grid module 2 Select the File Save As command 3 Change the name of the file to runl_huf gpr and select the Save button 4 Select the MODFLOW Run MODFLOW command 5 When MODFLOW has finished running sel
7. from a predefined covariance model 1 Select the Interpolation Interpolation Options command 2 Select the Kriging option 3 Select the Options button to the right of the Kriging option 6 18 1 Creating the Experimental Variogram There are a large number of options to be specified in the Kriging Options dialog Fortunately the defaults shown are adequate in most cases However a variogram must always be defined 1 Select the Edit Variograms button to bring up the Variogram Editor 6 12 GMS Tutorials Volume I 2 Select the New button in the section entitled Experimental variogram 3 Select the OK button to accept the defaults A curve should appear in the upper window of the Variogram Editor This curve is called an experimental variogram The experimental variogram is found by calculating the variance in data set values of each scatter point in the set with respect to each of the other points and plotting the variances versus distance between the points As can be seen in the plot of the experimental variogram the shape of the variogram indicates that at small separation distances the variance is small In other words points that are close together have similar data values With many data sets after a certain level of separation the variance in the data values becomes somewhat random and the variogram oscillates about a value corresponding to the average variance However with concentration data many of the points
8. 3 a The example in Figure 9 3 is a case where each solid is continuous through the model domain and there are no pinchouts Each of the solids is given a layer range defined by a beginning and ending grid layer number The resulting MODFLOW grid is shown in Figure 9 3 b Generating MODFLOW Data From Solids 9 5 b Figure 9 3 a A Set of Simple Solids with Grid Layer Assignments b The MODFLOW Grid Resulting From the Layer Assignments A more complex case with pinchouts is illustrated in Figure 9 4 a Solid A is given the layer range 1 4 and the enclosed pinchout solid B is given the layer range 2 2 The set of grid layers within the defined range that are actually overlapped by the model may change from location to location The layer range represents the set of grid layers potentially overlapped by the solid anywhere in the model domain For example on the left side of the problem shown in Figure 9 4 a solid A covers grid layers 1 2 3 and 4 On the right side of the model solid A is associated with grid layers 1 3 and 4 since the enclosed solid solid B is associated with layer 2 Likewise Solid C is associated with grid layers 5 and 6 on the left side of the model but only with layer 6 on the right side of the model where solid D is associated with layer 5 The resulting MODFLOW grid is shown in Figure 9 4 b 9 6 GMS Tutorials Volume I 9 4 2 O oa AON gt b Figure 9 4 a Gr
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10. File Register 9 3 Reading the Solids First we will read in a file containing a set of solids for the site we are modeling 1 Select the Open button lar 2 Locate and open the directory entitled tutfiles sol2mf 3 Select the file entitled start gpr 4 Click on the Open button There are five different solids in this project file There are two main units labeled upper_aquifer green and lower_aquifer red Inside of upper_aquifer there are two silty clay blue units and between upper aquifer and lower_aquifer there is a clay yellow unit 9 3 1 Viewing Cross Sections 1 Ifnecessary switch to the Solids module 9 4 GMS Tutorials Volume I 2 Select the check box next to the Solid Data folder in the Data Tree to hide the solids 3 Select the Data Cross Section Options command 4 Turn on the Cross section faces and click OK You should see cross sections in the main GMS window that show the stratigraphy for this site 9 4 Assigning Grid Layers to Solids 9 4 1 The first step in converting solids to MODFLOW data is to assign grid layers to the solids In this model we will use a five layer grid Layer Ranges Before we can convert the solids to MODFLOW data we must assign a layer range to each of the solids The layer range represents the consecutive sequence of layer numbers in the MODFLOW grid that are to coincide with the solid model A sample set of layer range assignments is shown in Figure 9
11. Interpolation Interpolation Options command Select the Inverse distance weighted option Select the Options button to the right of the Inverse distance weighted option In the Nodal function section at the top of the dialog select the Constant Shepard s method option In the section entitled Computation of interpolation weights select the Use all points option Select the OK button to exit the 2D IDW Interpolation Options dialog Select the OK button to exit the 2D Interpolation Options dialog To interpolate to the grid 8 9 Select the Interpolation to 2D Grid command Select the OK button 6 8 6 13 GMS Tutorials Volume I The JDW scheme is a simple moving weighted averages scheme To interpolate a value at a point a weighted average of the nearby scatter points is used The weights are an inverse function of distance The closer a scatter point is to the interpolation point the greater the weight given to the scatter point IDW Interpolation With Gradient Planes One of the problems with simple IDW interpolation is that the interpolated data set always tends toward the mean of the data set in the voids between scatter points As a result local minima or maxima in the voids in the scatter point set are not properly inferred To overcome this problem a nodal function can be computed at each scatter point A nodal function is a plane or quadratic function that is forced to pass through the scatt
12. Outcropping In this case the elevations for the scatter points have been adjusted so that the bottom of the first layer extends above the top of the second layer on the right side of the model After interpolating the values we will then adjust the elevations Interpolating the Values To interpolate the values 1 Switch to the 2D Scatter Point module Eel 2 Make the Case 3 scatter point set the active set by selecting it in the Data Tree 3 Select the Interpolation to MODFLOW Layers command 4 Select the OK button 2D Geostatistics 7 7 Note how the bottom of the first layer extends above the ground surface on the right side of the model 7 7 2 Correcting the Layer Values To correct the layer errors 1 Switch to the 3D Grid module 2 Select the MODFLOW Check Simulation command 3 Select the Run Check command 4 Select the Fix Layer Errors button In this case we wish to fix the errors for layer one by moving the bottom of layer one down to where it is just below the ground surface This can be accomplished using the Preserve top option 5 Select the Preserve top option 6 Make sure Layer 1 is selected in the list 7 Make sure the Inactivate thin cells option is on With this option instead of having a thin layer extend across the top of the grid the thin cells are inactivated This is useful since thin cells on the top of the grid often go dry 8 Select the Fix Selected Layer button 9 Ex
13. To interpolate the elevation values 3 Switch to the 2D Scatter Point module EJ 4 Make the casel scatter point set the active one by selecting it in the Data Tree 5 Select the Interpolation to MODFLOW Layers command The dialog you now see is used to define which scatter point data sets are interpolated to which MODFLOW arrays The data sets are listed at the top left and the MODFLOW arrays are listed at the top right of the dialog The mapped relationships are listed at the bottom of the dialog GMS tries to automatically map the relationships based on the data set names In this case all of the relationships were correctly mapped and we can continue 6 Select the OK button Notice that the interpolated layers match the cross section shown in Figure 7 1 You may wish to use the arrow buttons in the Mini Grid Display to view the cross sections along other rows Case 2 Embedded Seam The next case we will examine is illustrated in Figure 7 2 In this case the middle layer is an embedded seam that only exists on the left West side of the model This type of layer is more difficult to model with MODFLOW since a full array of K values must be defined for each layer Making the cells in the second layer inactive on the right side of the model will not work since this will result in a no flow boundary between the first and third layers To model the seam correctly we will use a three layer model and the second layer will exte
14. click on the TIN icon entitled sparse The letter A is now displayed in the icon for the sparse TIN This TIN can now be edited Also notice that the data tree is updated to show which TIN is active 4 In the data tree select the surface TIN Notice the A has switched back to the surface TIN 2 11 Hiding and Showing TINs When multiple TINs are in memory it is sometimes useful to hide some of the TINs temporarily This makes the display less cluttered and makes it easier to edit or visualize an individual TIN For example 1 In the Data Tree uncheck the TIN entitled sparse An alternative approach is to select the TIN and use click the Hide button A 2 12 Conclusion This concludes the Surface Modeling With TINs tutorial Here are the things that you should have learned in this tutorial e How to triangulate a set of points e How to visualize a TIN in different ways including using contours turning on the triangle faces and adjusting the lighting e How to edit the TIN by dragging adding and deleting vertices e How to smooth a TIN via interpolation e How to specify the active TIN and hide and show TINs CHAPTER 3 Stratigraphy Modeling Boreholes and Cross Sections The Borehole module of GMS can be used to visualize boreholes created from drilling logs Also three dimensional cross sections between boreholes can be constructed These cross sections show the soil stratigraphy betw
15. finite difference grid will be adjusted to match the elevations defined by the solid models Also the material assigned to each grid cell will be inherited from the solid that encompasses the cell Figure 9 2 shows a MODFLOW compatible grid of the cross section shown in Figure 9 1 Figure 9 2 Finite Difference Grid with Elevations and Materials Inherited from Solid Model One of the main benefits of using solid models to define stratigraphy for MODFLOW models is that it provides a grid independent definition of the layer elevations that can be used to immediately re create the MODFLOW grid geometry after any change to the grid resolution Generating MODFLOW Data From Solids 9 3 Solid models of stratigraphy can easily be created in GMS using the horizons approach The tutorial Stratigraphy Modeling Horizons And Solids explains how to create solid models using GMS Although not required it may be useful to complete the MODFLOW Conceptual Model Approach tutorial before doing this tutorial 9 1 Getting Started If you have not yet done so launch GMS If you have already been using GMS you may wish to select the File New command to ensure the program settings are restored to the default state 9 2 Required Modules Interfaces You will need the following components enabled to complete this tutorial e Sub surface characterization e Grid e Map You can see if these components are enabled by selecting the
16. have zero values and this tends to pull the experimental variogram back down 6 18 2 Creating the Model Variogram Once the experimental variogram is computed the next step is to define a model variogram A model variogram is a simple mathematical function that models the trend in the experimental variogram The model variogram is used in the kriging computations 1 Inthe section entitled Nested structure select the New button 2 For the Model function select the Gaussian option 3 Enter a value of 25 0 for the Nugget 1965 0 for the Contribution 63 0 for the Range 4 At this point there should be a reasonable fit between the model and first part of the experimental variogram The second part is difficult to fit in this case because of the zero values described above 5 Select the OK button to exit the Variogram Editor 6 Select the OK button to exit the Kriging Options dialog 7 Select the OK button to exit the 2D Interpolation Options dialog 6 18 3 Interpolating to the Grid To interpolate to the grid 1 Select the Interpolation to 2D Grid command 2 Select the OK button Error Reference source not found 6 13 Notice that this interpolation scheme results in an upward curvature towards the outside edges of the grid If you wanted to correct this you could add more scatter points with a concentration of 0 0 in these outlying areas 6 19 Switching Data Sets Now that we have interpolated to the grid using s
17. k Horizontal anisotropy i Vertical anisotropy Kh Kv 3 0 3 0 3 0 3 0 Select OK twice to exit both dialogs 9 9 Running MODFLOW We are now ready to run MODFLOW First we must save our MODFLOW simulation 1 Select the File Save As command 2 Change the name of the file to run1_lpf gpr and select the Save button 3 Select the MODFLOW Run MODFLOW command 4 When MODFLOW has finished running select the Close button The MODFLOW solution will automatically be read in 5 Select the Display Options button g 6 Turn off the Cell faces option and select OK to exit the dialog You should now see the head contours on the grid Cycle through the layers to see how the head contours change within the different layers You can also switch into side view to see the contours on the rows or columns Generating MODFLOW Data From Solids 9 13 9 10 Solids gt HUF Now we will use the HUF package in MODFLOW instead of the LPF package to define the hydraulic properties of the grid cells The Hydrogeologic Unit Flow HUF package is new in MODFLOW 2000 This package is designed to represent complex stratigraphic relationships in a grid independent fashion The hydro stratigraphy is represented using a set of hydrogeologic units Each unit is defined by two arrays one for the top elevation and one for the thickness The thickness values can be set to zero in regions of the model where the unit is not present When MODFLOW is e
18. respectively 3 Select the OK button The grid should now be visible Initializing the T PROGS Simulation The next step is to initialize the T PROGS simulation and define some general options including the azimuth angle background material and materials included in the simulation 1 Switch to the Borehole module g 2 Select the T PROGS New Simulation command The 7 PROGS Options dialog lists the materials in use on the boreholes and an Azimuth angle The azimuth angle represents the angle corresponding to the Strike X direction If there is anisotropy in the xy plane this angle should be set to the principle direction of the anisotropy If anisotropy is not present this angle should be coincident with the x axis the rows or j direction of the grid By default the azimuth angle is defaulted to a value that aligns it with the x axis of the grid This value corresponds to the negative grid rotation angle we entered in the grid frame This is because the grid rotation angle is counterclockwise from the x axis but the azimuth angle is clockwise from the y axis The upper part of the dialog lists the materials in the boreholes The first column of toggles indicates which materials are to be used in the analysis By default all materials associated with the boreholes are selected These toggles are necessary since it is possible that there may be materials defined in the materials list that are not associated with boreholes Fu
19. the New coverage command 4 7 2 Creating the Boundary Polygon Now we will create a polygonal boundary surrounding the boreholes Yo 1 Select the Plan View button tox 2 Select the Zoom tool a 3 While holding the Shift key down click on hole 6G This will zoom out so we can create the arc surrounding the boreholes 4 Select the Create Arc tool E o Figure 4 5 Map Polygon Surrounding Boreholes 5 Click out a polygon similar to the one in the figure above Single click in the upper left portion of the graphics window to begin creating Stratigraphy Modeling Horizons And Solids 4 9 the polygon Click out the rest of the points that make up the polygon Double click on the starting point to finish creating the polygon 6 Select the Feature Objects Build Polygons command 7 Select the Select Arc tool F 8 Select the arc that you just created 9 Select the Feature Objects Redistribute Vertices command 10 In the Arc redistribution section of the dialog make sure that the Specified Spacing option is selected Enter a value of 50 for the spacing 11 Select the OK button 12 Click anywhere off the arc to unselect it 4 7 3 Creating a TIN We will now use the polygon that we have defined to create a TIN 1 Select the Feature Objects Map gt TIN command 2 Select the OK button to accept the default TIN properties A TIN should now appear in the GMS graphics window 4 8 Creating th
20. the OK button Creating a Bounding Grid To generate a graphical representation of the contaminant plume we must first create a grid that bounds the scatter point set We will then interpolate the data from the scatter points to the grid nodes The grid will then be used to generate iso surfaces To create the grid 1 Select the Scatter Points Bounding Grid command 2 Notice that the x y and z dimensions of the grid are already defined The default values shown in the dialog cause the grid to extend beyond the scatter points by 10 on each side Also default values have also been entered for the number of cells in each direction We will leave the default values 3 Check to ensure that the default grid type is Mesh Centered Two types of grids are supported in GMS cell centered and mesh centered While cell centered is appropriate for groundwater models MODFLOW the mesh centered approach is more appropriate when the grid will be used solely for interpolation 4 Select the OK button A grid should appear on the screen that just encompasses the scatter point set 8 4 GMS Tutorials Volume I 8 7 Simple IDW Interpolation The next step is to select an interpolation scheme First we will use the inverse distance weighted interpolation scheme IDW 1 2 8 9 Select the Interpolation Interpolation Options command Select the Inverse distance weighted option Select the Options button to the righ
21. the header row because GMS recognized the headings You might want to take a minute and examine the format of the borehole file being imported 8 Click Finish 9 Select the Oblique View button tz You should now see a 3D view of the boreholes 3 4 Displaying the Hole Names Right now the boreholes probably appear very long and thin so much so that you cannot distinguish the different materials Let s adjust the borehole display options so we can see things better 1 Select the Display Options button a Take a minute to look at the display options available for boreholes Ignore the right side of the dialog for now we don t have sample data only stratigraphy data 2 Change the Diameter to 5 and click OK 3 Turn on the Hole Names option Stratigraphy Modeling Boreholes and Cross Sections 3 3 4 Select the OK button The boreholes should be more visible now and the names of the holes should appear at the tops of the holes 3 5 Editing the Materials Each of the colors represents a different type of soil The file we just imported specified a material ID number for each section of each borehole GMS created materials with those IDs and gave them default names and colors Let s change the material names and colors 1 Select the Edit Materials command 2 Double click on material_1 and change it s name to Clean_Sand 3 Click on the down arrow on the Material color pattern button to change the color
22. transition probability data created in the first phase of the tutorial Turn off Cell faces Before continuing we will turn off the display of the grid cell materials 1 Select the Display Options button a 2 Turn off the Cell faces item and select OK Building the Grid First we will create a four layer grid using the grid frame N 1 Switch to the Map module 2 Select the Feature Objects Map gt 3D Grid command 3 Select OK at the prompt 4 Enter 70 50 and 4 for the number of cells in the X Y and Z Dimensions respectively 5 Select the OK button Saving the Project Before continuing we will save the project under a new name 1 Select the File Save As command 2 Change the name of the project to tprobhuf gpr 3 Select the Save button Initializing MODFLOW Before interpolating the top and bottom elevations for the grid we will first initialize the MODFLOW data 1 Switch to the 3D Grid module 53 2 Select the MODFLOW New Simulation command to initialize MODFLOW 3 Select the Packages button T PROGS 5 17 4 Inthe Flow Package section select the HUF package then click OK 5 Select the OK button again to exit the MODFLOW Global Basic Package dialog 5 6 5 Interpolating the Layer Elevations Next we will import a set of scatter point data and interpolate the top and bottom elevations for the four layers of the MODFLOW grid To do this we will first interpolate the elevation
23. you have not yet done so launch GMS If you have already been using GMS you may wish to select the File New command to ensure the program settings are restored to the default state 8 2 Required Modules Interfaces You will need the following components enabled to complete this tutorial e Grid e Geostatistics You can see if these components are enabled by selecting the File Register 8 2 8 3 8 4 GMS Tutorials Volume I Importing a Scatter Point Set To begin the tutorial we will import a 3D scatter point set A 3D scatter point set is similar to a 2D scatter point set except that each point has a z coordinate in addition to xy coordinates As with the 2D scatter point set one or more scalar data sets can be associated with each scatter point set representing values such as contaminant concentration porosity hydraulic conductivity etc The 3D scatter point set we will import and use with this tutorial has previously been entered into a text file using a spreadsheet The file was then imported to GMS using the Import Wizard refer to the 2D Geostatistics tutorial for details on using the Import Wizard The project was then saved To read the project 1 Select the Open button as 2 Open the directory entitled tutfiles geos3d 3 Select the file entitled tank gpr 4 Click on the Open button 5 Ifnecessary switch to the 3D Scatter Point module ga 6 Select the Oblique View button tz A set of points shou
24. 00 0 for the Minimum value 11 Enter 15000 0 for the Maximum value 12 Select the OK button 8 17 2 Setting up the Animation To set up the animation 1 Select the Display Animate command 2 Turn on the Cross sections Iso surfaces command and click Next 3 Turn on the Animate cutting plane option 4 Turn on the Z cutting plane 5 Select the Finish button 8 17 3 Playing Back the Animation You should see some images appear on the screen These are the frames of the animation which are being generated Once they are all generated they are played back at a high speed 1 2 3D Geostatistics 8 11 After viewing the animation select the Stop E button to stop the animation When you are finished close the window and return to GMS 8 18 Setting up a Moving Iso Surface Animation Another effective way to visualize the plume model is to generate an animation showing a series of iso surfaces corresponding to different iso values To set up the animation 1 2 8 9 Select the Display Animate command Turn on the Cross sections Iso surfaces command and click Next Turn off the Animate cutting plane option Turn on the Animate iso surface option Enter 1000 0 for the Begin value Enter 15000 0 for the End value Select the Cap above option Select the Display values option Select the Finish button 10 After viewing the animation select the Stop E button to stop the animation 11
25. 6 1 Getting Started If you have not yet done so launch GMS If you have already been using GMS you may wish to select the File New command to ensure the program settings are restored to the default state 6 2 Required Modules Interfaces You will need the following components enabled to complete this tutorial e Grid e Geostatistics You can see if these components are enabled by selecting the File Register 6 2 GMS Tutorials Volume 6 3 Creating a Scatter Point Set Interpolation in GMS is performed using scatter points A set of 2D scatter points is defined by a set of xy coordinates A group of scatter points is called a scatter point set Each scatter point set has a list of scalar data sets Each data set represents a set of values that can be interpolated to a TIN mesh or grid 2D scatter point sets can be created inside GMS using the Create Scatter Points tool 1 Switch to the 2D Scatter Point module 1 2 Select the Create Scatter Points tool 3 Click on the screen a few times in different places You are creating scatter points When you create each point GMS automatically assigns a data set value at the point You can change it so that GMS prompts you for the data set values 4 Select the Scatter Points Scatter Point Options command 5 Turn on the Confirm data set value option and click OK 6 Click on the screen Now you are prompted to enter a data set value every time you create a new poi
26. Compute button in the upper left corner of the dialog At this point a window should appear listing the output from the GAMEAS utility For this problem GAMEAS may take up to 2 3 minutes to run depending on the speed of your computer When it finishes Successful Completion should be written to the window and the Abort button should switch to say Close 2 When GAMEAS finishes select the Close button At this point the plots in the upper right corner of the dialog should be updated These plots display the transition probabilities for each material with respect to each of the other materials The rows correspond to Clean_Sand Sand_w fines Silt and Clay respectively Likewise the columns correspond to Clean Sand Sand _wi fines Silt and Clay in that order Thus the plot in the first row and first column represents the probability of transitioning from clean sand to clean sand The plot in the first row and second column represents the probability of transitioning from clean sand to sand w fines etc The plots can be better viewed by maximizing the plot 3 Right click on the plot in the first row and the first column 4 Select the Maximize Plot command in the resulting pop up menu 5 Select the Esc button to minimize the plot You may wish to use this feature to view other plots Each of the plots contains two curves depicting the transition probability The dashed line represents the transition probability measured from
27. E HUF DATA SETS ocooocccccoconccnnncononaoncononaonannonaonarnonaonarnonarnarnonaons 5 15 OL Turn of Cell faces A A ER ERA E 5 16 Table of Contents vii 36 2 Building the diia atea 5 16 3 6 3 SAVING he Pro A Sc 5 16 IOA lt Initializing MODELO WM A aioe ata at eae aan He 5 16 5 6 5 Interpolating the Layer Elevations ccccccscceceeseescesesseesesseesecseeecseescesecseeseceeecnseeseeseeseeaeeaeeseeas 5 17 966 Rin S chy Sa beeen ld ca L Ta A Ets de de DIO Ca ea eke Cfo IO a 5 18 HOT Viewine the Results bo Ri ii a ae DOREY ea Ras Be aE E ERS 5 19 5 7 CONCLUSION 2 A Re Se ne A 5 20 2D GEOSTA FISTICS wiiescsvsssscevsscsnansscossccevesetvsesdsovescsuuesuscssensscesevedsesseeevsoxesedtessinessseaededsseddeedueevevesvsaeccens 6 1 6 1 GETTING STARTED 4 245 cc 002 SesseiSedeoets o eines Ban daba ate sob eds 6 1 6 2 REQUIRED MODULES INTERFACES ncos is cdesdcessstcesnes cvs dess daa 6 1 6 3 CREATING A SCATTER POINT SET iii iia 6 2 6 4 IMPORTING A SCATTER POINT SET rinnan sieri E E E EEA EE Aa NE E aa aiiai 6 2 6 5 CHANGING THE DISPLAY OPTION Sii oniar taerae e areen ae a e ae a aie E eain raio 6 4 6 6 CREATING A BOUNDING GRID vosenn esere ena a di 6 5 6 7 SELECTING AN INTERPOLATION SCHEME c ccccssssseceessececseseeceesnececsesaececseceeeesaeeecsesaeeecensaeeseseeeeneaas 6 5 6 8 LINEAR INTERPOLATION 24 sc cece ooh eects A we SIA A Eh eo me ees kits 6 5 6 9 VIEWING THE RESULTS Gecseecbes sete Cases ie i ie e aei iee 6 6 6 10 VIEWING THE
28. Frame command 3 Select the BM tool 4 Select the grid frame by clicking in the graphics window At this point you should see the outline of the grid frame appear The size location and orientation of the grid frame can be edited in two ways 1 by editing the values in the grid frame dialog and 2 by click and dragging on the control points displayed on the grid frame The symbols and the corners of the grid frame can be dragged to resize the grid frame and the small circle just to the side of the lower right corner of the grid frame can be used to rotate the frame Clicking and dragging anywhere in the middle of the frame drags the entire frame to a new location The vertical component of the grid frame can be edited by changing the view using the view macros on the left side of the Grid Frame dialog 1 Double click on the grid frame to bring up the Grid Frame Properties dialog 2 Change the Angle of rotation value to 40 and hit the Tab key This aligns the grid with the regional ground water flow direction 3 Enter the following values for the origin and dimension of the grid frame Origin Dimension X 1710 Y 1010 Z 130 80 4 Select the OK button to exit the dialog ue 5 Select the Frame Image button a x Now we are ready to create the grid 1 Select the Feature Objects Map gt 3D Grid command 5 4 5 T PROGS 5 7 2 Enter 70 50 and 20 for the number of cells in the X Y and Z dimensions
29. Groundwater Modeling System TUTORIALS 50 ft d top elev 200 ft bi top elev 150 ft bot elev bi ot elev 150 ft ft d top el 400 ft 7 ft d top elev 400 ft bot elev PCE TCE gt Ground Water Spill Flow Direction o Monitoring well locations Volume e Sub surface Characterization TINs Boreholes Solids T PROGS GMS version 5 0 2D amp 3D Geostatistics Interpolating Layer Elevations Solids gt MODFLOW Environmental Modeling Research Laboratory GMS 5 0 Tutorials Copyright 2003 Brigham Young University Environmental Modeling Research Laboratory All Rights Reserved Unauthorized duplication of the GMS software or user s manual is strictly prohibited THE BRIGHAM YOUNG UNIVERSITY ENVIRONMENTAL MODELING RESEARCH LABORATORY MAKES NO WARRANTIES EITHER EXPRESS OR IMPLIED REGARDING THE PROGRAM GMS AND ITS FITNESS FOR ANY PARTICULAR PURPOSE OR THE VALIDITY OF THE INFORMATION CONTAINED IN THIS TUTORIAL DOCUMENT The software GMS is a product of the Environmental Modeling Research Laboratory EMRL of Brigham Young University emrl byu edu Last Revision October 11 2004 TABLE OF CONTENTS 1 INTRODUC FION civ sstescetsccsecsssacesosscscceetevsenscessdsseusveveundsssesseesacees seateostesgaacssedsssedevssesseucdesevssxeetessercesesess 1 1 1 1 SUGGESTED ORDER OF COMPLETION
30. MODFLOW Layer Arrays list select the Top Elevations Layer 1 item then select the Map button Select the OK button To view the results 1 6 7 Turn off the display of the scatter points by turning off the topo toggle in the Data Tree Switch to the Borehole module B Hide all the boreholes by unchecking the box next to the Borehole Data folder in the Data Tree Switch to the 3D Grid module Es Select a cell somewhere near the center of the grid Select the View I Axis button amp Select the View J Axis button ta Redistributing the Interior Layer Elevations We will now use the Redistribute Layers command to distribute the elevations of the interior layer boundaries between the current elevations at the top and bottom of the grid We will make the top layer a little larger than the other three layers The other three layers will be evenly distributed 1 2 Select the Grid Redistribute Layers command Enter a value of 0 35 in the Fraction column for layer 1 and select the Tab key Note how the fractions for the other layers are automatically updated Select the OK button Select OK at the prompt to confirm that we are overwriting the MODFLOW elevations Note the change in the layer elevations Having a thicker layer at the top reduces difficulties caused by cell wetting and drying Run TSIM We are now ready to run TSIM T PROGS 5 19 1 Switch to the Borehole module 8 2 Select the 7
31. PROGS Run TSIM command 3 Change the Simulation name to simhuf 4 Enter 5 for the Number of realizations 5 Select the Generate HUF arrays option in the TSIM output section 6 Enter 20 in the Num Z edit field This defines the number of layers in the background grid and controls the level of detail in the resulting HUF units 7 Accept the other defaults and select the OK button 8 When the GAMEAS utility finishes select the Close button 9 The MCMOD and TSIM utilities are executed Select the Close button when TSIM finishes 5 6 7 Viewing the Results The output from T PROGS is automatically converted to a series of HUF data sets The HUF data sets are organized in the 3D Grid Data tree The first HUF data set is automatically loaded and the Display hydrogeologic units option is turned on Note that the stratigraphic definition is independent of the MODFLOW grid boundaries 1 Switch to the 3D Grid module cay 2 Expand the HUF Data folder under the 3D Grid Data folder Next expand the simhuf folder All five realizations are listed under the simhuf folder The active HUF data set simhuf 1 is identified by a bolded name and selected icon You may wish to view other HUF data sets by clicking on the other items in the list You may wish to also view different columns and rows of the MODFLOW grid As you view the results the solid lines represent the boundaries of the MODFLOW grid cells The filled colors in the background
32. R 5 4 5 4 PHASE I MULTI LAYER ORTHOGONAL GRID eesesereserereresererererererererererererererererererererererererererereres 5 4 5 4 1 Loading the Borehole Data cccceccccccsccessesceseeseesetseeseceeecseeecaceesensesseeseceseecnseesensesseesesieeseeeeeenaes 5 5 oE EE Y A A A A IATE EE E A ET EE 5 5 5 4 3 Viewing the Borehole Data c cceccccccsccscssscscesscesesseesesseeecseeeccaceescsesseesecsessccaeeseesecuaeeeceaeeneeseeaeenaes 5 5 S44 Building the 3D Grd is e gabe EE EEE AREE E EEEE 5 6 5 4 5 Initializing the T PROGS Simulation c cccccceccecssceseessesessseeecnseeecusenseeececeeseesesseseseseeenseesenaeeseeaees 5 7 5 4 6 Developing the Vertical Markov Chains cccceccscesessseseesseesenseeseusecseeseceeeecseeseeseeseeseseeneenseesentes 5 8 5 4 7 Define the Strike Dip Transition Trends ccccccccccccsscsseeeneescececseeesesecuseeecuseeseeseeeeeaesneseeenseeree 5 11 ILE TRUNISIM A a O a a aaa an e id o dad labo e A 5 12 AO gt Viewing th Results a lid 5 12 53 PHASE IT SINGLE TATER GRID nikin io a E E S OA 5 13 5 5 Building the Single Layer Grid cccccccccccsccscsescesesseeseeseeeecuseeececeeseeeceseeseesecieesesieeeecnseesesseeseeaeeneees 5 14 3 32 SAVING the PrOJCO Lata dados oda tidad lalalala acicate iii teats 5 14 5 5 3 MODFLOW Layer Elevations 0 c ccccccsccecesscetesseeseeesseesecaeeeecaseescceeseesecsessecaseecnaeeseesesseeaeeaeeaeeas 5 14 Ip ARUN ISIM ia e eaa a e lado la ed 5 15 5 6 PHASE II GENERATING MULTIPL
33. S on a routine basis The tutorials are not intended to teach groundwater modeling concepts They are only meant to illustrate the use of GMS In addition to this document the online GMS Help document also describes the GMS interface Typically the most effective approach to learning GMS is to complete the tutorials before browsing the GMS Help document 1 1 Suggested Order Of Completion In most cases the tutorials can be completed in any desired order However some of the tutorials are pre requisites for other tutorials Tutorials that have other tutorials as pre requisites will indicate it at the beginning of the tutorial 1 2 Demo vs Normal Mode The interface for GMS is divided into eleven modules Some of the modules contain interfaces to models such as MODFLOW Such interfaces are typically contained within a single menu Since some users may not require all of the modules or model interfaces provided in GMS modules and model interfaces can be licensed individually Modules and interfaces that have been 1 2 GMS Tutorials Volume I licensed are enabled using the Register command in the File menu The icons for the unlicensed modules or the menus for model interfaces are dimmed and cannot be accessed GMS provides two modes of operation demo and normal In normal mode the modules and interfaces you have licensed are undimmed and fully functional and the items you have not licensed are dimmed and inaccessible In demo m
34. TATISTIC S o ot h cdenctdecescessosnccesecvoscscuesecsescseosseseascese cdenestensessusesdusesdexcsecssesanvenstedencscoscesenteseese 8 1 8 1 GETTING STARTED iao e e a e a e e e ia 8 1 8 2 REQUIRED MODULES INTERFAGES iso sscec ssicesescessiecesnccesta ce ie AEAN EEE E EE EREN AEE EAR 8 1 8 3 IMPORTING A SCATTER POINT SET ccssssccesssececsssceceessececssseececeneeecsesaeeecseseesecsaeeecsesaeesceeaeeeesseeeeneaaes 8 2 8 4 DISPLAYING DATA COLORS E A A 8 2 8 5 Z MAGNIPICATION a a a adie hots banal and achat an h 8 3 8 6 CREATING A BOUNDING GRID i cccis tt kek eRe Ran ch es econ eo he Rows 8 3 8 7 SIMPLE IDW INTERPOLATION comi ia 8 4 8 8 DISPLAYING ISO SURFACES ci dadas 8 4 8 9 INTERIOR EDGE REMOVAL s ccsssssccssssseessscecesnstsecssseesesssseecsensssecescescessssecsensssesseseeessnssecsenansessesees 8 5 S10 SPECIFIED RANGE Costo A A ts 8 5 8 11 USING THE VERTICAL ANISOTROPY OPTION cseccccesssececseseeeecsnececsesseeecseseeeesseeeceesaeeecsesseeeesneeeenses 8 6 8 12 IDW INTERPOLATION WITH GRADIENT PLANES ooooocccononnnocononononnnnnccononnnnnonnnnnnnnnnncnnnnnnncnnnnnnnnnnnnnnnnos 8 7 8 13 IDW INTERPOLATION WITH QUADRATIC FUNCTIONS ccccssseessssceceesececseseeeeceeeeecessaeeecseaaeeeenneeeenes 8 7 8 14 OTHER INTERPOLATION SCHEMES cccssscecsssceeesssececessuececseseeeeeseeecsesaeeecsesaesecseeeeesssaeeecsesaeseesneeeenses 8 8 8 15 VIEWING THE PLUME WITH A CROSS SECTION ccccccssssscecseeeeessneceessaececseseeee
35. al function section at the top of the dialog select the Quadratic option 4 In the section entitled Computation of nodal function coefficients select the Use all points option 5 Select the OK button to exit the DW Interpolation Options dialog 6 Select the OK button to exit the Interpolation Options dialog To interpolate to the grid 1 Select the Interpolation to 3D Grid command 2 Select the OK button 8 8 GMS Tutorials Volume I 8 14 Other Interpolation Schemes Two other 3D interpolation schemes natural neighbor interpolation and kriging are supported in GMS However these schemes will not be reviewed in this tutorial You are encouraged to experiment with these techniques at your convenience 8 15 Viewing the Plume With a Cross Section While iso surfaces are effective for displaying contaminant plumes it is often useful to use color shaded cross sections to illustrate the variation in the contaminant concentration Next we will cut a horizontal cross section through the center of the plume 1 5 Switch to the 3D Grid module 53 Z Select the Side View button A Select the Create Cross Section tool AA Cut a horizontal cross section through the grid by clicking to the left of the grid moving the cursor to the right of the grid and double clicking Cut the cross section through the middle of the iso surface Select the Oblique View button tz Before we examine the cross section we will turn o
36. als Volume I 14 For the column with heading c change the type to Dataset The data set in this file represents concentrations of a contaminant The No data option can be used to specify a key value in the file used to indicate a lack of information For example if no measurement was taken at one of the points we might enter 999 or some other key value for the concentration and specify 999 as the No data value in the Import Wizard GMS will then know to ignore these points when we do interpolation later The key value should be a value that would not normally be encountered in the data set In this case we don t need to use this option 15 Select the Finish button A set of points should appear on the screen Changing the Display Options You can change the appearance of the scatter points using the Display Options dialog 1 Switch to the 2D Scatter Point module L 2 Select the Display Options button a 3 For the Scatter point symbols change the Color option to Data 4 Select the button to the right of the Scatter point symbols toggle 5 Choose one of the triangle shaped symbols 6 Select the OK button to exit the Symbol Picker dialog 7 Select the OK button to exit the Display Options dialog Each of the points should now be displayed with a colored triangle The color of the symbol represents the relative concentration of the contaminant at the point When displaying colored symbols it is useful to also disp
37. bias to Yes and select OK to exit the dialog 3 Select the Solids Solids gt MODFLOW command 4 Select OK to execute the Solids gt MODFLOW command Figure 9 7 Row 30 of Model Grid Using Target Minimum Thickness and Top Cell Bias Your grid should now look similar to Figure 9 7 9 8 Converting the Conceptual Model We are now ready to convert our conceptual model and run MODFLOW In the interest of time the conceptual model has already been built and was read in when we read in the project file For more information on conceptual models refer to the MODFLOW Conceptual Model Approach tutorial N 1 Switch to the Map module Y 2 Switch to plan view by selecting the View K Axis button a 3 Select the Feature Objects Map gt MODFLOW command 4 Ensure the All applicable coverages option is selected and select OK 9 12 GMS Tutorials Volume I 9 8 1 Using Materials to Define Hydraulic conductivity Now we need to set the option for MODFLOW to use the material assigned to the grid cell to define the hydraulic conductivity for the cell 1 2 Switch to the 3D Grid module Y Select the MODFLOW LPF Package command Select the Use Material IDs option in the Layer property entry method section of the dialog Select the Material Properties button in the Layer data section of the dialog Enter the values for the properties for each material shown in the table below Horizontal
38. ce that all of the triangles connected to the vertex were deleted By default this is what happens when a vertex is deleted The resulting void can be filled with triangles by using the Create Triangle tool to manually create triangles However another option is available for deletion that causes the region surrounding a deleted vertex to be automatically retriangulated 3 Select the Modify TIN Vertex Options command 4 Turn on the option entitled Retriangulate after deleting 5 Select the OK button 6 Choose the Select Vertices tool 7 Select one of the vertices in the interior of the TIN 8 Select the Edit Delete command Notice that the triangles next to the deleted vertex are deleted but the resulting void is retriangulated 2 8 Smoothing a TIN 2 8 1 As mentioned above a TIN represents a piecewise linear surface If the vertices defining the TIN are sparse the linear surface defined by the triangles may appear excessively irregular A TIN can be smoothed in GMS by copying the TIN vertices to a scatter point set subdividing the TIN into a denser set of triangles and interpolating the elevations to the new vertices in the TIN The resulting TIN is still piecewise linear but it appears much smoother since the triangles are smaller Deleting the TIN We will now go through an example of TIN smoothing but first we will read in a different TIN since we have made several changes to this TIN 1 Select the New but
39. cecssscecsessscecsessececenssecsssseeecsesaececeeseecssseesecsesaeeecesaecsesaeeessesseeeceeaaees 2 8 2 10 CHANGING THE AGTIVE TIN A a a sa 2 8 ZA SHIDING AND SHOWING INS int E 2 9 2 12 CONCLUSION iii 2 9 STRATIGRAPHY MODELING BOREHOLES AND CROSS SECTIONS sssssessesssesccesccssecesese 3 1 3 1 GETTING STARTED minnein enini iiei a e i eee 3 1 3 2 REQUIRED MODULES INTERFACES ccccccssssesssecssscsceecsseceececsaeceeeecsaeceseeecsseceseeecsseceseeeesaeceeeeesaeensees 3 1 3 3 READING BOREHOLE DATA ccccssscesssscesessececsesaececesacecesueeecsesaeeeceeeeeeessaeeecsesueeeceaeeeessueeeseesueeecseaaees 3 2 3 4 DISPLAYING THE HOLE NAMES cx ss ceccses2 ccssusccesentdecesn eit cvedqeesd cadbesevsuiecedscteasehesnceesedsncseessuedevsteceenevsoued 3 2 3 5 EDITING THE MATERIALS ore si ee Swe 3 3 3 6 CREATING BLANK CROSS SECTIONS cssssscecsssseeecenscecessseeecsssaececseseecseaesecsesseseceesaeeseaeeesseaeescseaaees 3 3 3 7 BUILDING CROSS SECTIONS 2G 5G 3G 6G AND 6G 7G ce cccccccssssscecececeessseceeceecseseesssaeeeeeeeeeeneaaes 3 4 3 8 BUILDING CROSS SECTIONS 1G 7G AND 4G 5G ou ecccccecssscccesssececseeeeesessececsssaeceeceeeeesesaeeesssaeeesseaeees 3 5 3 81 Building Cross Section 1G 7 Gor at dicten iaa Weta BEDE eA 3 5 3 8 2 Building Cross Section 4G 5G ccccecccccsscssssescesesscescuseesceseeseesecseeeceeeececeeseesessessesaeseeeneeeeeeaeereeaee 3 6 3 9 BUILDING CROSS SECTIONS 7G 2G 5G 6G AND 6G BGoooccccccconononana
40. ch to the 3D Grid module Es The material set simulations are organized into a Material Sets folder in the Data Tree 2 In the Data Tree expand the Material Sets folder under the 3D Grid Data folder 3 Expand the sim3d folder All five material sets are listed under the sim3d folder The active material set sim3d 1 is highlighted 4 Change material sets by selecting the material set entitled sim3d 2 Notice the grid display is updated 5 In the mini grid display select the down arrow to view the second layer 7 View the side of the grid by selecting the View J Axis button D 8 Use the arrow buttons in the Mini Grid Plot section of the Tool Palette to view different cross sections 9 Return to plan view by selecting the View K Axis button 10 View the material set properties by right clicking on any of the material sets and selecting the Properties command from the pop up menu You may wish to repeat this with other material sets to confirm that all material sets have the same proportions 11 Select the OK button to exit the Material Set Info dialog This completes the 3D grid portion of this tutorial 5 5 Phase ll Single Layer Grid This portion of the tutorial will demonstrate the generation of multiple material sets for a single layer model When developing a single layer model the modeler must determine how to distribute the hydraulic conductivity values within the layer A common approach is to del
41. cnseeeceeaeeecsesaeeeeeeeeeensas 8 8 8 16 USING THE TRUNCATION OPTION c ccccsssscecesssecesssececesseececseseecesseeecsesaeeecseseesesseeeessesaeeecseaaeeeeseeeeenses 8 9 8 17 SETTING UP A MOVING CROSS SECTION ANIMATION cccesssssessssceceesseeecseseeeecsneeeceeaeeecseaaeeeseeeeeenes 8 9 8 17 1 Display Options srecen uss sees seu A A aa NEEE 8 10 8 17 2 Setting up the Animation ARA 8 10 8 17 3 Playing Back the Animation ccccccccccccssecsssescsseesceesscesecseesecsesseesecueseeeseeseesenseeseceeeeenteeeenaeets 8 10 8 18 SETTING UP A MOVING ISO SURFACE ANIMATION ccssccccesssececseseeeeessececsssaeeeceeeeeeessaeeecsssaeeeceeeaeens 8 11 SLO CONCLUSION A Boece oR A Se Re 8 11 9 GENERATING MODFLOW DATA FROM SOLIDS ccscssssssssscssssccsssssscsssssssssscssssssescsssssssesees 9 1 9 1 GETTING STARTED aoe coore u e E a Roca eas cs ecco aes canta Si Bee oe os 9 3 9 2 REQUIRED MODUEES INTERFACES ido asii 9 3 9 3 READING THE SOLIDS aa 9 3 93A Viewing Cross SCCHONS edida Sinn due ti adhe ie tein A At A ib i 9 3 9 4 ASSIGNING GRID LAYERS TO SOLIDS cc cccssssscecseseecesssececseaececseeeeeeeseeecsesaececeeeeesesaeeecsesaeeecneeeeeneas 9 4 DAT Layer RANGES shite si tots besos tesa e RADA ROAD o den E AR IATA o Paka do EAS 9 4 9 4 2 Assigning Layers tOsSOlIAS sci 2 ei ce pectic Be es ek SI DA 9 6 9 5 SOLIDS gt MODELO Maia dd ciao 9 7 9 31 Displayingthe 3D Grid iii AAA EE E E IEA aio 9 7 9 5 2 AA AAA 9 8 033 Solids g
42. column is the Y values and the fourth column is the data set values for the points 7 Make sure the Delimited option is selected 8 Make sure all the following options are selected Space Tab Treat consecutive delimiters as one and Skip leading delimiters 9 Set the starting import row to 1 This option allows you to skip over any extra information that might be at the top of the file there is none in this case 10 Turn on the Heading row option 11 Select the Next button Step 2 of the Import Wizard allows you to specify what the data in the file means 12 Select 2D Scatter Points as the GMS Data Type The data associated with 2D scatter points is now displayed in the Mapping options section Now we tell GMS what each column in the file means We do this by selecting the correct data type in the Type row of the spreadsheet for each column in the file The Type row is the first row in the spreadsheet The options in the combo box changes depending on the GMS data type selected in the top of the dialog Since we specified we were using a heading row in the first step GMS looked at the headings and automatically found and mapped the X and Y columns by selecting the X and Y selection in the Type row of the spreadsheet 13 Locate the Type row the first row in the spreadsheet The first column is ID s for each point In the Type row for the first column select the Label selection in the combo box 6 4 6 5 GMS Tutori
43. ct OK to exit the dialog 5 Select OK to exit the Horizons gt HUF dialog On hitting OK GMS creates HUF data from the horizon data 4 9 4 Viewing the HUF Data Now we will view the HUF data that was just created 1 Switch to the 3D Grid module 2 Select the View J Axis button Er 3 Select the Display Options button a 4 Select the MODFLOW tab and turn on the Display hydrogeologic units toggle 4 18 GMS Tutorials Volume I 5 Select OK to exit the dialog You should now see the different hydrogeologic units present in the 3D grid You can look at different columns in the grid by selecting the arrows below the mini grid display to change the current column At this point you could further develop the MODFLOW model and run it However we will not do that as part of this tutorial 4 10 Conclusion This concludes the Stratigraphy Modeling Horizons And Solids tutorial Here are some of the key concepts in this tutorial Solids can be created directly from boreholes if you assign horizon numbers to the borehole contacts Horizons are numbered consecutively in the order that the strata are deposited from the bottom up You can model pinchouts using the Represent missing horizons implicitly option You can use borehole cross sections to further control the Horizons gt Solids process Borehole cross sections and solid cross sections are two different things You can create MODFLOW HUF data directl
44. cts tool Eh 2 Select the top of the lower red material on hole 8G shown in the figure below 4 4 GMS Tutorials Volume I 2G 5G 7G 4G 66 16 gt 3G 8G Z gt lL X Figure 4 1 Contacts for Horizon 1 3 While holding down the Shift key select the same contact on holes 5G and 7G 4 Select the Properties button E 5 Assign a horizon ID of 1 and select the OK button 4 6 2 Assigning Horizon ID 2 Now we will assign a horizon ID of 2 to the top of the lower Silty or Clayey Fine Sand blue layer 1 Select the borehole contacts shown in the figure below Stratigraphy Modeling Horizons And Solids 2G 5G x 7G 4G 6G 1G gt gt 3G x 8G gt Fa La x Figure 4 2 Contacts for Horizon 2 2 Select the Properties button eS 3 Assign a horizon ID of 2 and select the OK button 4 6 3 Assigning Horizon ID 3 Horizon ID 3 will be assigned to the top of the upper silty clay red layer 4 5 4 6 GMS Tutorials Volume I 2G gt ai 5G 7G 46 60 16 ai gt a 4 30 gt a 8G ye gt Ys La x Figure 4 3 Contacts for Horizon 3 1 Select the borehole contacts shown in the figure above 2 Select the Properties button ESA 3 Assign a horizon ID of 3 and select the OK button 4 6 4 Assigning Horizon IDs 4 and 5 The top of the Clean Sand green layer will be assigned horizon ID of 4 1 Select all of the contacts at the top of the green mater
45. dialog displays basic statistics related to the active data set such as minimum maximum and mean data values 6 Select the OK button to exit the Data Set Info dialog 7 Select the Done button to exit the Data Calculator dialog The contour plot now displayed represents the data set we just computed Any new data set computed using the Data Calculator is automatically designated the active data set 6 21 Conclusion This concludes the 2D Geostatistics tutorial Here are some of the key concepts in this tutorial e You can interpolate from a sparse set of points to a different set of points usually more dense and defining a surface by using 2D scatter points e 2D scatter points can be created by hand or imported from a file e There are several interpolation algorithms available in GMS e Linear algorithms do not interpolate beyond the convex hull of the scatter points e Anisotropy and truncation can be used to help control the interpolation process CHAPTER Interpolating Layer Data For sites with complex stratigraphy and three dimensional flow a multi layer MODFLOW model can be much more accurate than a one layer two dimensional model When creating multi layer models defining layer data can be challenging This is particularly true for cases involving embedded seams pinchouts and truncations Fortunately GMS contains a suite of tools for interpolating and manipulating layer elevation data With these tools
46. e solids Borehole cross sections are different from cross sections you cut through solids They are described in the tutorial entitled Stratigraphy Modeling Boreholes and Cross Sections If you have created borehole cross sections and the Use borehole cross section data option is on in the Horizons to Solids dialog GMS will use the borehole cross sections to help guide the interpolation as it builds the solids If you were to cut cross sections through the resulting solids the solid cross sections would more closely resemble the borehole cross sections although they would not match exactly To do this we will read in a previously defined set of cross sections To read in the cross sections 1 Select the New button L 2 Select No at the prompt 3 Select the Open button a 4 Locate and open the directory entitled tutfiles horizons 5 Select the file entitled xsects gpr and click Open Stratigraphy Modeling Horizons And Solids 4 15 You should now see the cross sections that have been created between the boreho 6 7 8 les Select the Boreholes Horizons gt Solids command Turn on the Use borehole cross section data option Select OK We will now create cross sections through the solids in the same location as the borehole cross sections 9 10 11 12 We wi 20 21 22 23 Switch to the Solids module a Switch to Plan View earn Select the Create Cross Section tool F
47. e Objects Map gt 3D Grid command 3 Select OK at the prompt to confirm that we are creating a new grid 4 Enter 70 50 and 1 for the number of cells in the X Y and Z dimensions respectively 5 Select the OK button Saving the Project Before continuing we will save the project under a new name 1 Select the File Save As command 2 Change the name of the project to tprob2d gpr 3 Select the Save button MODFLOW Layer Elevations Grid layer elevations could be interpolated from scatter point data using the to MODFLOW Layers command in the 2D Scatter Point module However for the sake of simplicity we will use constant top and bottom elevations with our model T PROGS 5 15 5 5 4 Run TSIM We will use the same transition probability data developed in the first phase of this tutorial for the 2D case Therefore we can proceed directly to running TSIM 1 Switch to the Borehole module g 2 Select the T PROGS Run TSIM command 3 Enter simulation name as sim2d 4 Enter 5 for the Number of realizations Accept the other defaults and select the OK button 5 Select OK at the prompt to confirm that each borehole will be simplified to a single sample in the calculations 6 When the GAMEAS utility finishes select the Close button The MCMOD and TSIM utility are executed Helpful information is displayed at the top of the dialog including Elapsed Time and Time Remaining This simulation runs much faster tha
48. e Solids We are now ready to create the solids from the borehole horizons 1 Switch to the Borehole module 8 2 Select the Boreholes Horizons gt Solids command In the Horizons to Solids dialog we will pick the interpolation scheme used to create the solids Also we will specify how the top and bottom elevation of the stratigraphy model will be determined 3 In the Top elevation section of the dialog select the Top of boreholes option This means that the top of every borehole will be used in interpolating to the top of the solid 4 In the Bottom elevation section of the dialog select the Constant elevation option and enter a value of 35 4 10 GMS Tutorials Volume I 5 In the Interpolation method section of the dialog select Inverse distance weighted for the interpolation and in the Nodal function section select Constant 6 Select the OK button 4 8 1 Viewing the Solids To view the solids 1 Select the Oblique View button t 2 Switch to the Solids module 3 Select the Display Options button a 4 Turn on the Solid faces 5 Select the OK button You have created a simple solid of five layers of different materials 4 8 2 Cutting Cross Sections We can better view the solids by cutting some cross sections Bi 1 Select the Plan View button tox 2 Select the Create Cross Section tool AA 4 8 3 Stratigraphy Modeling Horizons And Solids 4 11 Figure 4 6 Cross s
49. e figure below x Figure 3 1 Blank Cross Sections 3 7 Building Cross Sections 2G 5G 3G 6G and 6G 7G You are now ready to delineate soil layers for the blank cross sections We do this using define arcs and polygons just like the arcs and polygons in the Map module of GMS If you are unfamiliar with the Map module don t worry It is not necessary to understand this tutorial You may wish however to First we will build cross sections 2G 5G 3G 6G and 6G 7G Since the boreholes in each of these three cross sections match each other in the sequence of borehole regions we will use the tools in the Cross Section Editor to automatically create the arcs and polygons delineating the soil layers 1 Switch to the Select Cross Section tool HA 2 Double click on 2G 5G s icon to bring up the Cross Section Editor 3 Select the Automatch button Note that a set of arcs connecting matching borehole contacts was automatically created Stratigraphy Modeling Boreholes and Cross Sections 3 5 4 Select the Build button Note that a set of polygons representing soil layers was built Every polygon is filled with the color of the soil material it represents 5 Select the OK button to close the Cross Section Editor 6 Repeat the above steps for cross sections 3G 6G and 6G 7G Now you should see the three newly built cross sections The other cross sections are not displayed because we have not defined any polygons yet
50. easily Linear Interpolation First we will try simple linear interpolation 1 Select the Interpolation Interpolation Options command 2 Select the Linear option 3 Select the OK button To interpolate to the grid 4 Select the Interpolation to 2D Grid command 5 Select the OK button 6 6 GMS Tutorials Volume I 6 9 Viewing the Results A set of contours should now be displayed The concentrations have been interpolated to the grid 1 Select the Oblique View button t Notice that the grid has been deformed to match the contours Color shading the entire surface can provide an even more effective display of the grid 2 Switch to the 2D Grid module EH 3 Select the Data Contour Options command 4 For the Contour method select Color Fill 5 Turn on the Smooth option in the Fill options 6 Select the OK button Notice that the outer part of the grid still has a concentration value equal to zero When linear interpolation is performed the scatter points are triangulated to form a temporary TIN A plane equation is computed for each triangle in the TIN and the coefficients of the plane equation are used to interpolate to points inside the triangle Therefore linear interpolation cannot be performed for grid nodes outside the convex hull of the TIN the boundary of the TIN As a result these nodes are assigned a value of zero However for this application a value of zero is appropriate since the concentration
51. ect the Close button The MODFLOW solution will automatically be read in You should now see the head contours on the grid You may see some red triangles on certain grid cells These cells have gone dry the water table is below the bottom of the cell in this simulation Cycle through the layers to see how the head contours change within the different layers You can also switch into side view to see the contours on the rows or columns 9 11 Conclusion This concludes the Generating MODFLOW Data From Solids tutorial Here are some of the key concepts in this tutorial e Solids can be used to define the MODFLOW layer elevations They can also be used to create MODFLOW HUF data e You must assign layer ranges to the solids before using them to create a layered grid 9 16 GMS Tutorials Volume I You can use a minimum thickness to avoid thin cells You can also specify a top cell bias to make the top grid layer thicker If you are using solids to define your MODFLOW layer data you probably want to use the Material IDs approach to define the hydraulic properties of grid cells based on their material
52. ections through Stratigraphy Model 3 9 Cut three cross sections through the solid similar to the ones shown above Single click to begin making a cross section and double click to end In the Data Tree select the check box next to the Solid Data folder to hide all of the solids Select the Data Cross Section Options command Turn on the Cross section faces and select OK Switch to the TIN module YY Hide the TIN by unchecking it in the Data Tree Select the Oblique View button tz You can now see how the different surfaces of the solids vary Modeling Pinchouts Many times it is desirable to have certain horizons pinch out or stop This is accomplished with the Represent missing horizons implicitly toggle in the Horizons to Solids dialog Consider the boreholes shown in the figure below 4 12 GMS Tutorials Volume I 3G 8G 5 5 4 3 0 0 Y X Figure 4 7 Sample boreholes with missing horizons Notice that on borehole 3G that horizons 1 and 2 are missing On hole 8G horizon 4 is missing 3G 8G 5 5 mb ia Figure 4 8 Cross Section between holes 3G and 8G Figure 4 8 is a cross section through the solids between holes 3G and 8G Notice the layer that is associated with horizon 4 This layer passes through hole 8G even though the horizon is not present on hole 8G This is because with the Represent missing horizons implicitly option turned off hole 8G is ignored when interpolatin
53. edsensetesessesvecsssestecessees 7 1 7 1 GETTING STARTED ooien A As ad 7 1 12 REQUIRED MODULES INTERFACES qieset iiei EEE EEE TEE E e Ea 7 1 7 3 INTERPOLATING TO MODFLOW LAYERS ccseccesesssecesssececeseececseacececseeecsesaeeecseeeeeesseeecsesaeeesseaaees 7 2 7 4 SAMPLE PROBLEMS td 7 2 T CASE T COMPLETE LAYER S i ld lis odas 7 2 73 1 Importing the Scatter Point SOUS rire ee aa E a 7 3 DI Mr ATA AEEA AE EE EE E E A AT 7 3 7 5 3 Interpolating the Elevation Values ccccccccccccccesceseeeseesscesecesecsecsaecacecseecseeeseeeseeeseeseeeeeeeneeeeeeaas 7 3 7 6 CASE 2 EMBEDDED SEAM ninien niee oha aa oeae a ea e rai e aeara aaee Eeee ai ane e 7 4 LOA Interpolatins the Values li ei idos 7 5 70 2 Correcting the Layer Dala iii aras 7 5 7 7 CASE 3 OUTCROPPING iriri cases see hos aa a e Rok Sih dock ee nck RAE ec ee ee 7 6 7 7 1 Interpolating the Values acire iieiea aae EA Eeee E A oE 7 6 Tha Correcting the Layer Values id did lnea dada nda 7 7 7 8 CASE 4 BEDROCK TRUNCATION ccccccessssceceesseeeceesceceesececseaeeecenseeeessaeeecsesseseceeseessesaeeesessaeeeceeaeees 7 7 78 1 Activating the Inactive Cells irc beets Gawd avis dit 7 8 7 8 2 Interpolating the Valesi tinei ioiii EE i aii iE a EAEE E e ii AE E Ea 7 8 783 Viewing the Result A AAA A 7 8 viii GMS Tutorials Volume I 7 04 Correcting the Layer Valles iia atte acti 7 9 78 37 Viewing the Corrected Layers A Ea A 7 9 7 9 CONCLUSION ise 7 10 8 3ID GEOS
54. een two boreholes Once a set of cross sections is built they can be displayed in 3D space to help characterize and visualize the soil stratigraphy at a site In this tutorial you will learn how to construct a set of cross sections for site characterization using borehole data 3 1 Getting Started If you have not yet done so launch GMS If you have already been using GMS you may wish to select the New File command to ensure the program settings are restored to the default state 3 2 Required Modules Interfaces You will need the following components enabled to complete this tutorial e Sub surface characterization e Geostatistics You can see if these components are enabled by selecting the File Register 3 2 GMS Tutorials Volume I 3 3 Reading Borehole Data The first step in the construction of borehole cross sections is to create some boreholes We will read in a set of previously defined borehole logs 1 Switch to the Borehole module Y 2 Select the Open button a 3 Locate and open the directory entitled tutfiles horizons 4 Change the Files of type to Text Files txt 5 Select the file entitled holes txt and click on the Open button This brings up the Text Import Wizard All kinds of data can be imported into GMS via the Text Import Wizard 6 Turn on the Heading row option and click Next 7 Change the GMS data type to Borehole data Notice all the column types are automatically assigned based on
55. ents enabled to complete this tutorial Sub surface characterization Grid Geostatistics Map MODFLOW Stochastic tools You can see if these components are enabled by selecting the File Register Phase I Multi Layer Orthogonal Grid The underlying equations solved by the T PROGS software require an orthogonal grid with constant cell dimensions AX AY and AZ The AX values can be different from the AY and AZ values and the AY values can be different from the AZ values but all cells must have the same AX AY and AZ dimensions However GMS can be used with T PROGS with both uniform and non uniform grids If a uniform grid is used the T PROGS calculations are carried out directly on the grid cells If a non uniform grid is used the T PROGS calculations are carried out on a uniform background grid which bounds the user defined grid After the calculations are complete the material ids are transferred from the background grid to the user defined grid by comparing the coordinates of the cell center for each cell in the user defined grid to determine which cell in the background grid contains the cell center The material id for this cell is then inherited by the cell in the foreground grid Best results are obtained when the user defined grid is uniform When the HUF package is used a more sophisticated approach is used to handle the stratigraphic layering in the vertical direction The heterogeneity from the background grid is pres
56. er point and approximate the nearby scatter points in a least squares sense When the interpolation is performed rather than computing an average of the data set values at the scatter point locations an average is computed of the nodal functions of the nearby scatter point evaluated at the interpolation point This approach allows local trends to be inferred and often results in a more accurate interpolation The next scheme we will try is IDW interpolation with planar nodal functions 1 Select the Interpolation Interpolation Options command 2 Select the Options button to the right of the Inverse distance weighted option 3 In the Nodal function section at the top of the dialog select the Gradient plane option 4 Select the OK button to exit the 2D IDW Interpolation Options dialog 5 Select the OK button to exit the 2D Interpolation Options dialog To interpolate to the grid 6 Select the Interpolation to 2D Grid command 7 Select the OK button 6 14 Using the Horizontal Anisotropy Option The interpolation can be stretched in a horizontal direction by using the horizontal anisotropy option in conjunction with a specified azimuth This option might be used if for example you know a contaminant plume is elongated in a particular direction due to groundwater flow Error Reference source not found 6 9 To change the horizontal anisotropy 1 2 7 8 Select the Plan View button e Select the Interp
57. erved in a set of HUF input arrays In the first phase of this tutorial we will run T PROGS on a multi layer orthogonal MODFLOW grid The MODFLOW model will use the Layer Property Flow LPF Package with the Material ID option for assigning aquifer properties With this option each cell in the grid is assigned a material id and the aquifer properties Kh Kv etc associated with each material are automatically assigned to the layer data arrays for the LPF package when the MODFLOW files are saved The T PROGS software generates multiple material sets arrays of material ids each of which represents a different realization of the aquifer heterogeneity When running a MODFLOW simulation in stochastic mode GMS automatically loads each of the N material sets generated by the T PROGS software and saves N different sets of MODFLOW input files The N solutions resulting from these simulations can be read into GMS and used to perform risk analyses such as probabilistic capture zone delineation 5 4 1 5 4 2 5 4 3 T PROGS 5 5 Loading the Borehole Data The first step in setting up the T PROGS simulation is to read in the borehole data 1 Select the Open button gt 2 Locate and open the directory entitled tutfiles t progs 3 Select the file entitled LH 3D gpr 4 Click on the Open button Saving the Project We want to save the changes to our project as we go but leave the original project unchanged So we will create a new p
58. even complex geologic strata can be modeled quickly and easily This tutorial describes how to use these tools most effectively This tutorial involves the use of scatter points interpolation and MODFLOW Therefore a familiarity with MODFLOW and scatter points is helpful Although not required it would be a good idea to have completed the 2D Geostatistics tutorial as well as either the MODFLOW Grid Approach or MODFLOW Conceptual Model Approach tutorials before completing this tutorial 7 1 Getting Started If you have not yet done so launch GMS If you have already been using GMS you may wish to select the File New command to ensure the program settings are restored to the default state 7 2 Required Modules Interfaces You will need the following components enabled to complete this tutorial 7 2 7 3 GMS Tutorials Volume I e Grid e Geostatistics e Map You can see if these components are enabled by selecting the File Register interpolating to MODFLOW Layers 7 4 7 5 One of the ways that the top and bottom elevation arrays for each MODFLOW layer can be created is by interpolating from a set of scatter points The interpolation can be performed directly to the MODFLOW arrays using the to MODFLOW Layers command in the Interpolation menu in the 2D Scatter Point module The scatter points can be imported from a tabular scatter point file For regions with complex stratigraphy such as embedded seams or ou
59. everal different interpolation schemes we may wish to review the results by replotting some of the interpolated data sets We can switch back to one of the previous data sets using the Data Tree 1 Switch to the 2D Grid module H 2 Select the Plan View button 2m 3 In the Data Tree select the c_linear item 4 Use the up and down arrows to switch between the datasets and watch the contours change 6 20 Using the Data Calculator Occasionally it is useful to use the Data Calculator to compare two data sets generated by interpolation As an example we will use the Data Calculator to compute the difference between the kriging and natural neighbor data sets 1 Select the Data Data Calculator command The currently available data sets are listed in the top of the dialog Each data set is assigned a letter Data sets are referenced in the mathematical expression using the letters The c krig data set should be labeled I and the c nn quad data set should be labeled j The next step is to enter an expression to compute the absolute value of the difference between the krig and nn data sets 2 Inthe Expression field enter abs j l 3 Inthe Result field enter Difference 4 Select the Compute button Now that we have computed the difference between two data sets it is helpful to view some basic statistics related to the new data set 5 Select the Data Set Info button 6 14 GMS Tutorials Volume I The resulting
60. ff the display of the iso surfaces 1 2 3 Select the Display Options button a Turn off the so surfaces option Select the OK button Next we will set up the display options for the cross section 1 2 3 4 Select the Data Cross Section Options command Turn on the Jnterior edge removal option Turn on the Contours option Select the OK button Finally we will reset the Contour options 1 Select the Data Contour Options command 3D Geostatistics 8 9 2 For the Contour method select the Color Fill option 3 Select the OK button 8 16 Using the Truncation Option Notice the range of contaminant concentration values shown in the color legend at the upper left corner of the Graphics Window A large percentage of the values are negative This occurs due to the fact that a higher order nodal function was used Both the quadratic and the gradient plane nodal functions infer trends in the data and try to preserve those trends In some regions of the grid the values at the scatter points are decreasing as you move away from the center of the plume This decreasing trend is preserved by the interpolation scheme and the interpolated values approach zero and eventually become negative in some areas However a negative concentration does not make sense This problem can be avoided by turning on the Truncate values option in the Interpolation Options dialog This option can be used to force all negat
61. finite element meshes 2 1 Getting Started If you have not yet done so launch GMS If you have already been using GMS you may wish to select the File New command to ensure the program settings are restored to the default state 2 2 Required Modules Interfaces You will need the following components enabled to complete this tutorial e Sub surface characterization e Geostatistics You can see if these components are enabled by selecting the File Register 2 2 GMS Tutorials Volume I 2 3 Importing Vertices To begin reviewing the tools available for TIN modeling we will first import a set of vertices from a file To import the vertices 1 Ifnecessary switch to the TIN module A 2 Select the Open button Pd 3 In the Open dialog locate and open the directory entitled tutfiles tins 4 Select the file entitled verts gpr and click Open A set of points should appear on the screen The points are not connected by triangles yet 2 4 Triangulating To construct a TIN we must triangulate the set of vertices we have imported To triangulate the points 1 Select the Build TIN Triangulate command The vertices should now be connected with edges forming a network of triangles The triangulation is performed automatically using the Delaunay criterion The Delaunay criterion ensures that the triangles are as equi angular as possible In other words wherever possible long thin triangles are avoided A more comple
62. g horizon 4 and hole 3G is ignored when interpolating horizons 1 and 2 Stratigraphy Modeling Horizons And Solids 4 13 3G 8G 5 5 4 3 3 2 0 1 2 1 0 E Y X Figure 4 9 Placement of Missing Horizons However with the toggle turned on the missing horizons are placed as shown in Figure 4 9 3G 8G Sd Figure 4 10 Cross Section between Boreholes 3G and 8G Figure 4 10 is a cross section through the solids created with the Represent missing horizons implicitly option turned on Notice that the layers associated with horizon 4 and 2 pinch out To redo the solids creation with this option turned on 1 Switch to the Solids module a 2 Select the Edit Delete All command 3 Switch to the Borehole module 8 4 Select the Boreholes Horizons gt Solids command 5 Turn on the Represent missing horizons implicitly 4 14 GMS Tutorials Volume I 6 Select OK 4 8 4 Cutting Cross Sections To view some cross sections E JH 1 Switch to Plan View tex 2 Switch to the Solids module 3 Select the Create Cross Section tool FA 4 Cut three cross sections through the solids similar to the previous cross sections 5 In the Data Tree select the check box next to the Solid Data folder to hide all of the solids 6 Switch to Oblique View 8 4 8 5 Using Borehole Cross Section Data Now we will use borehole cross sections to help guide the creation of th
63. he 3D Scatter Point module E 2 Select the Interpolation Interpolation Options command 3 Change the Vertical anisotropy value to 0 4 4 Select the OK button 5 Select the Interpolation to 3D Grid command 6 Enter c_idw_const2 for the new data set name 7 Select the OK button As can be seen there is now much more correlation in the horizontal direction 3D Geostatistics 8 7 8 12 IDW Interpolation With Gradient Planes As discussed in the 2D Geostatistics tutorial DW interpolation can often be improved by defining higher order nodal functions at the scatter points The same is true in three dimensions Next we will try ZDW interpolation with gradient plane nodal functions 1 Select the Interpolation Interpolation Options command 2 Select the Options button to the right of the Inverse distance weighted option 3 In the Nodal function section at the top of the dialog select the Gradient plane option 4 Select the OK button to exit the IDW Interpolation Options dialog 5 Select the OK button to exit the Interpolation Options dialog To interpolate to the grid 1 Select the Interpolation to 3D Grid command 2 Select the OK button 8 13 IDW Interpolation With Quadratic Functions Next we will try DW interpolation with quadratic nodal functions 1 Select the Interpolation Interpolation Options command 2 Select the Options button to the right of the Inverse distance weighted option 3 In the Nod
64. he default interpolation method 3 Enter a name of new_elev for the new data set 2 8 GMS Tutorials Volume I 4 Select the OK button The contours on the TIN now appear smoother To better view the variation in the surface 5 Select the Oblique View button tz 2 8 5 Deleting the Scatter Point Set The TIN smoothing process is now completed Since we no longer need the scatter point set we will delete it 1 Select the Edit Delete All command 2 9 Reading Another TIN In GMS several TINs can be modeled at once For example we will now read in another TIN without first deleting the existing TIN 1 Switch to the T Ns module BY 2 Select the Open button a 3 In the Open dialog select the filter 4 Select the file entitled surface tin 5 Click on the Open button You should now see two TINs displayed at once 2 10 Changing the Active TIN Whenever multiple TINs are being modeled one of the TINs is designated as the active TIN Only the active TIN can be edited A TIN can be designated as the active TIN using the Data Tree or by double clicking on the TIN with the select TINs tool 1 Expand the TIN Data item in the data tree if necessary 2 Choose the Select TINs tool MY Notice that triangular shaped icons appear at the center of each TIN A TIN is selected by selecting the TIN icon The active TIN has a letter A displayed in the center of the icon Surface Modeling With TINs 2 9 3 Double
65. he diagonal transition rates are defined from the lens lengths using equation 5 6 The lens lengths in the horizontal directions are derived from the lens length ratios entered by the user for each material using the spreadsheet on the bottom left of the dialog These ratios represent the lens length in the horizontal direction vs the lens length in the vertical direction GMS sets up the matrix using a default ratio of approximately 10 0 The off diagonal terms in the rate matrix are then inherited from the vertical transition rates and then scaled by dividing by the lens length ratio Once the Markov Chains have been defined by the Lens length ratios method the other four methods listed in the Markov Chains section of the dialog can be used to view edit the Markov Chain data In this case we will accept the default data for both the strike and dip directions 5 12 GMS Tutorials Volume I 5 4 8 5 4 9 1 Select the Next button to exit the Strike X Markov Chains dialog and proceed to the Dip Y Markov Chains dialog 2 Select the Finish button 3 Select the Save button Run TSIM With the Markov Chains defined in all three primary directions we are now ready to select the Run TSIM command to generate the material sets The Run TSIM command actually launches up to three different utilities GAMEAS MCMOD and TSIM If the Fit curve to a discrete lag option is used as is the case with our simulation GAMEAS is launched f
66. ial 2 Select the Properties button ESA 3 Assign a horizon ID of 4 and select the OK button The top of the upper Silty or Clayey Fine Sand blue layer is horizon 5 1 Select the top contact on each borehole 2 Select the Properties button eS 3 Assign a horizon ID of 5 and select the OK button Stratigraphy Modeling Horizons And Solids 4 7 4 6 5 Displaying the Horizon IDs We ll turn on the display of the horizon IDs to make sure they are all correct 1 Select the Display Options button a 2 Turn off the Hole names and turn on the Horizon IDs and select OK Your model should look like the one in Figure 4 4 8 5 5 4 5 5 5 3 3 2 z 4 1 4 9 3 3 2 3 5 0 0 E 5 0 4 3 0 3 Nn Figure 4 4 Horizon IDs 3 Select the Display Options button a 4 Turn off the Horizon IDs and turn on the Hole names and select OK 4 7 Constructing the TIN You are now ready to construct a TIN using the map module We will construct a TIN that will define the boundary of the solid The horizons will also be interpolated to the TIN to define a surface for each horizon The solid is created by filling between each of the surfaces defined by the interpolation 4 8 GMS Tutorials Volume I 4 7 1 Setting up the Coverage We will define a polygon that will serve as the boundary for the TIN M N 1 Switch to the Map module 2 In the Data Tree right click on the Map Data folder and then from the pop up menu select
67. id Layer Assignments for a Set of Solids with Pinchouts b The MODFLOW Grid Resulting From the Layer Assignments When assigning layer ranges to solids care must be taken to define associations that are topologically sound For example since solid B in Figure 9 4 a is enclosed by solid A solid B could not be assigned a layer range that is outside the layer range of solid A Assigning Layers to Solids Now we are ready to assign the grid layers to the solids The figure below is a cross section through our site Notice that we must have a minimum of five grid layers in order to represent all of the layers present in this cross section In this case the upper aquifer green will be assigned to layers 1 3 The silty clay blue will be assigned to layer 2 The clay yellow will be assigned to layer 4 and the lower_aquifer red will be assigned layers 4 5 Generating MODFLOW Data From Solids 9 7 Figure 9 5 Cross section through Model Domain 1 Select the Select Solids tool Ga 2 Double click on upper_aquifer 1 solid in the Data Tree For the Begin layer enter 1 and for the End layer enter 3 Click OK 3 Repeat this process on the remaining solids entering the values shown in the following table upper_aquifer 1 Begin layer End layer 9 5 Solids gt MODFLOW 9 5 1 We are now ready to convert the solids to MODFLOW data When the Solids gt MODFLOW command is executed the grid will
68. ighbor option 3 Select the Options button to the right of the Natural neighbor option Error Reference source not found 6 11 As with ZDW interpolation we can use higher order nodal functions if desired We will use the quadratic option 4 Select the Quadratic option 5 In the Bounding pseudo points section turn OFF the Extrapolate beyond convex hull option Natural neighbor interpolation triangulates the scatter points as part of the interpolation process The boundary of the resulting TIN corresponds to the convex hull of the scatter points Computing points outside this hull is considered to be extrapolation If the values are not extrapolated a zero value is assigned to the grid nodes outside the convex hull Thus turning off the Extrapolate beyond convex hull option is a simple way to ensure that the concentrations on the perimeter of the map are zero 6 Select the OK button to exit the Natural Neighbor Options dialog 7 Select the OK button to exit the 2D Interpolation Options dialog To interpolate to the grid 8 Select the Interpolation to 2D Grid command 9 Select the OK button 6 18 Kriging The last interpolation scheme we will test is kriging Kriging is based on the assumption that points that are near each other have a certain degree of spatial correlation but points that are widely separated are statistically independent Kriging is a set of linear regression routines that minimize estimation variance
69. ineate zones of hydraulic conductivity by examining the subsurface stratigraphic data The modeler often faces a difficult task of trying to determine a reasonable strategy for delineating two dimensional zones of hydraulic conductivity based on complex 3D borehole data The 2D T PROGS approach provides a simple rational approach to representing borehole data in a single layer MODFLOW model The 2D T 5 14 GMS Tutorials Volume I 5 5 1 5 5 2 5 5 3 PROGS approach is similar to the 3D approach The first step is to generate the Markov chains in the three principal directions Since these data have already been generated in the first phase of the tutorial we will reuse the Markov Chain information for this phase The main difference between the two approaches is what happens when TSIM is executed For the 2D case GMS determines the predominant material at each borehole and creates a single sample at the xy location of the borehole corresponding to the predominant material type These samples are input to TSIM in the place of the entire borehole log that is input to TSIM in the 3D case TSIM then performs a 2D indicator simulation in the xy plane and each of the resulting material sets is conditioned to the simplified borehole data Building the Single Layer Grid First we will use the same grid frame created in the first phase of the tutorial and create a single layer grid N 1 Switch to the Map module 2 Select the Featur
70. inherit the elevations as well as the material from each of the solids Displaying the 3D Grid The grid was read in as part of the project but the display of the grid cells was turned off Let s turn on the display of the grid 1 Switch to the 3D Grid module B 2 Select the Display Ortho Mode command 3 Select the Display Options button a 4 Turn on the Cell edges toggle to display the grid cells 5 Select OK to exit the dialog 9 8 GMS Tutorials Volume I You should now see the 3D grid 9 5 2 Initializing MODFLOW We must initialize MODFLOW before we can execute the Solids gt MODFLOW command 1 Select the MODFLOW New Simulation command Now we will also set up the starting heads for MODFLOW We will assign a constant value as the starting head 2 3 4 gt Select the Starting Heads button Select the Constant gt Grid button Enter a value of 250 0 and select OK to exit the dialog Select OK twice to exit both dialogs 9 5 3 Solids gt MODFLOW 1 2 3 Switch to the Solids module Select the Solids Solids gt MODFLOW command Make sure that the Boundary Matching option is selected and select OK to execute the Solids gt MODFLOW command The Solids gt MODFLOW command may take less than a minute to a few minutes to complete depending on the speed of your computer 9 6 Viewing the Grid Now we will see how our grid has changed First we will hide the s
71. irection of the ground water flow at the site and the two ends of the model will be marked as constant head boundaries 5 2 GMS Tutorials Volume I Regional Ground Water Flow Direction Borehole Locations Boundary of Local Scale Model Figure 5 1 Conceptual Representation of Site to be Modelled Seventy four borehole logs are available in the vicinity of the site A 3D oblique view of the borehole data is shown in Figure 5 2 The borehole logs indicate that the geology corresponds to an alluvial system with considerable heterogeneity One approach for dealing with such a site in GMS would be to create a solid model of the site stratigraphy including a detailed 3D representation of each of the lenses However the solid modeling approach will not work at this site since the heterogeneity is too complex and there is not sufficient correlation between the boreholes to develop meaningful cross sections By contrast the transition probability geostatistics approach is ideally suited for this type of situation With this approach we will first analyze the borehole data to determine transitional tendencies proportions and mean lens lengths These data will then be used to generate multiple realizations of the site heterogeneity as input for a stochastic simulation Each of the realizations will preserve the geologic tendencies inherent in the borehole data and will be conditioned to the borehole data the cells c
72. irst to develop the transition trends from the borehole data GAMEAS only runs if this option is used for the vertical Markov Chains MCMOD then takes the one dimensional Markov Chains defined in the three primary directions and formulates a three dimensional Markov Chain This Markov Chain is then read into TSIM and TSIM generates the material sets Running TSIM can take anywhere from several minutes to several hours depending on the number of materials the resolution of the grid and the number of material sets desired To ensure that this tutorial can be completed in a reasonable amount of time we will only create five material sets 1 Select the 7 PROGS Run TSIM command 2 Change the simulation name to sim3d 3 Enter 5 for the Number of realizations 4 Accept the other defaults and select the OK button 5 When the GAMEAS utility finishes select the Close button The MCMOD and TSIM utility are then executed The output from MCMOD and TSIM is displayed in the bottom part of the progress dialog Helpful information is displayed at the top of the progress dialog including Elapsed Time and Time Remaining 6 Select the Close button when TSIM finishes Viewing the Results The output from T PROGS is a series of material sets The material sets are organized in the Data Tree associated with the 3D Grid Module The first material set is automatically loaded and the Cell faces display option is turned on T PROGS 5 13 1 Swit
73. is fit is sufficiently accurate and we can proceed to the next step However it is often useful to explore the other options for fitting the curves 5 10 GMS Tutorials Volume I 6 Select the Edit transition rates option With this option the user directly edits the transition rates and the mean proportions using the two spreadsheets at the bottom of the dialog The proportion and rates for the background material need not be defined The proportion for the background material is adjusted so that the proportions sum to 1 0 The transition rates involving the background material are adjusted so that the row sums obey K ties 0 A E E E A 5 4 k 1 and the column sums obey K DES 0 PP A caylee 5 5 j l where j is the row index k is the column index p is the proportion and r is the transition rate 7 Select the Edit embedded transition probabilities option With both this option and the next option Edit embedded transition frequencies GMS parses the borehole data and computed embedded transition probabilities or transition frequencies and displays the results in the matrix in the lower right part of the dialog The transition rates can be computed from the transition probabilities or frequencies This option is described in more detail in the T PROGS Users Guide 8 Select the Edit maximum entropy factors option With this option the diagonal terms of the rate matrix are computed from the mean lens lengths using
74. it both dialogs Notice how the outcropping is now properly modeled When finished viewing the cross section 10 Select the View K Axis button button Ey h 7 8 Case 4 Bedrock Truncation The final case we will examine is shown in Figure 7 4 The site has three layers but the layers are truncated by the bedrock on the sides of the model We will model this situation by inactivating the cells on the perimeter of the model that are below the bedrock elevation We will also adjust the layer bottom elevations as necessary to accurately model the bedrock GMS Tutorials Volume I 7 8 1 7 8 2 a b Figure 7 4 Typical a East West and b North South Cross Section Through Site with Layers Truncated by Bedrock Activating the Inactive Cells The last interpolation caused cells on the top layer to become inactive We must first activate those cells 1 Click anywhere outside the grid to unselect any selected cells 2 Select the Grid Activate Cells command Interpolating the Values To interpolate the values 1 Switch to the 2D Scatter Point module e 2 Make the Case 4 scatter point set the active set by selecting it in the Data Tree 3 Select the to MODFLOW Layers command 4 Select the OK button 7 8 3 Viewing the Results To view the results 7 8 4 7 8 5 2D Geostatistics 7 9 1 Switch to the 3D Grid module ca 2 Select a cell near the middle of the g
75. ive values to have a value of zero 1 Switch to the 3D Scatter Point module P 2 Select the Interpolation Interpolation Options command 3 Turn on the Truncate values option 4 Select the Truncate to min max of data set option 5 Select the OK button To interpolate to the grid 1 Select the Interpolation to 3D Grid command 2 Enter c_idw_quad_trunc for the name of the new data set 3 Select the OK button Notice that the minimum value listed in the color legend is zero 8 17 Setting up a Moving Cross Section Animation It is possible to create several cross sections at different locations in the grid to illustrate the spatial variation of the plume This process can be automated using the Animation utility in GMS An animation can be generated showing a color shaded cross section moving through the grid 8 10 GMS Tutorials Volume I 8 17 1 Display Options Before setting up the animation we will first delete the existing cross section turn off the color legend and reset the contour range 1 Switch to the 3D Grid module a 2 Select the Select Cross Sections tool AA 3 Select the cross section by clicking on the diamond shaped symbol displayed on the cross section 4 Select the Edit Delete command 5 Select the Data Color Ramp Options command 6 Turn off the Legend option 7 Select the OK button 8 Select the Data Iso surface Options command 9 Select the Specified range option 10 Enter 10
76. lay a color legend 8 Select the Data Color Ramp Options command 9 Turn on the Legend option 10 Select the OK button Notice that the concentrations vary from zero to about 100 0 6 6 6 7 6 8 Error Reference source not found 6 5 Creating a Bounding Grid The goal of this tutorial is to generate a series of contour plots illustrating the plume To do this we will first create a grid that bounds the scatter point set and then we will interpolate the concentrations from the scatter points to the grid nodes The grid will then be contoured 1 Select the Scatter Points Bounding 2D Grid command Notice that the x and y dimensions of the grid are already defined The default values shown in the dialog cause the grid to extend beyond the scatter points by 10 on each side 2 Enter 60 for the number of cells in the x direction 3 Enter 40 for the number of cells in the y direction 4 Select the OK button A grid should appear on the screen that just encompasses the scatter point set Selecting an Interpolation Scheme The next step is to select an interpolation scheme Several interpolation schemes are supported in GMS because there is no one interpolation scheme that is superior in all situations Typically the best approach is to try several schemes and then determine which scheme is giving the most reasonable results GMS has been structured in such a way that several different schemes can be tested quickly and
77. ld appear on the screen Notice that the points are arranged in vertical columns This hypothetical set of points is meant to represent a set of measurements of contaminant concentration in the vicinity of a leaky underground storage tank Each column of points corresponds to a borehole or the path of a penetrometer along which concentrations were measured at uniform intervals The goal of the tutorial is to use the tools for 3D geostatistics in GMS to interpolate from the scatter points to a grid and generate a graphical representation of the plume Displaying Data Colors Next we will change the display options so that the color of each point is representative of the concentration at the point 1 Select the Display Options button a 2 For the Scatter point symbols change the Color option to Data 3 Select the OK button 4 Select the Data Color Ramp Options command 8 5 8 6 3D Geostatistics 8 3 5 Turn on the Legend option 6 Select the OK button Notice that most of the values are zero The nonzero values are all at about the same depth in the holes This pattern is fairly common when dealing with light non aqueous phase liquids LNAPLs which form a pancake shaped plume and float on the water table Z Magnification Next we will magnify the z coordinate so that the vertical variation in the data is more apparent 1 Select the Display Settings command 2 Enter a value of 2 0 for the Z magnification 3 Select
78. lume I 8 11 3 Enter 3000 for the Minimum value 4 Enter 9000 for the Maximum value 5 Select the OK button Using the Vertical Anisotropy Option The scatter points we are using were obtained along vertical traces In such cases the distances between scatter points along the vertical traces are significantly smaller than the distances between scatter points along the horizontal plane This disparity in scaling causes clustering and can be a source of poor results in some interpolation methods The effects of clustering along vertical traces can be minimized using the Vertical Anisotropy option in the Interpolation Options dialog The z coordinate of each of the scatter points is multiplied by the vertical anisotropy parameter prior to interpolation Thus if the vertical anisotropy parameter is greater than 1 0 scatter points along the same vertical axis appear farther apart than they really are and scatter points in the same horizontal plane appear closer than they really are As a result points in the same horizontal plane are given a higher relative weight than points along the z axis This can result in improved accuracy especially in cases where the horizontal correlation between scatter points is expected to be greater than the vertical correlation which is typically the case due to horizontal layering of soils or due to spreading of the plume on the top of the water table To change the vertical anisotropy 1 Switch to t
79. mand Notice that the color of the vertices changes when they are locked Once a set of vertices is locked the coordinates of the vertices cannot be changed 3 Click once outside the TIN to unselect the vertices 4 Select one of the vertices that you just locked 5 Attempt to edit the vertex by dragging or by entering new coordinates in the Edit Window Locked vertices can be unlocked by selecting the vertices and selecting the Modify TIN Lock Unlock Vertices command Adding Vertices As mentioned above when working with TINs it is often necessary to edit a TIN by adding supplemental vertices to the TIN to provide more resolution or detail in an area of interest Vertices can be added to a TIN in GMS simply by pointing and clicking 1 Select the Plan View button mu 2 Select the Create Vertex tool 3 Place the cursor in the interior of one of the triangles in the TIN and create a vertex by clicking the mouse button The new Z value for the vertex is computed using a linear interpolation of the surrounding vertices The vertex is selected and can be edited if unlocked using the edit fields in the Edit Window 2 6 GMS Tutorials Volume I 2 7 6 Deleting Vertices It is also frequently necessary to delete vertices To delete the vertex you just created 1 Make sure the vertex is still selected or select it again if necessary using the Select Vertices tool X 2 Select the Edit Delete command Noti
80. module amp 2 Uncheck the check box next to the top elevation TIN in the Data Tree to hide the TIN 3 Switch to the Borehole module B E 4 Select the Frame Image button AK Stratigraphy Modeling Boreholes and Cross Sections 3 11 z La x Figure 3 7 Site Stratigraphy Your cross sections should be similar to the figure above 3 11 Conclusion This concludes the Stratigraphy Modeling Boreholes and Cross Sections tutorial Here are the things that you should have learned in this tutorial Boreholes can be imported via the Text Import Wizard The display options for boreholes can be changed to aid in visualization When borehole cross sections are first created they are blank The Cross Section Editor can be used to define how the soil layers are connected A TIN can be used to make the top of the cross section conform to the ground surface CHAPTER 4 Stratigraphy Modeling Horizons And Solids The Solid module of GMS is used to construct three dimensional models of stratigraphy Once the solids are created cross sections can be cut anywhere on the model the volumes of the solids can be computed and the solid model can be used to define elevation data for numerical models such as MODFLOW In this tutorial you will learn how to construct a set of solid models using the horizon method in GMS The term horizon refers to the top of each stratigraphic unit that will be represe
81. n the 3D case 1 Select the Close button when TSIM finishes 2 View the results by following the procedure outlined in section 5 4 9 Viewing the Results in phase I of this tutorial 5 6 Phase lll Generating Multiple HUF Data Sets In the final phase of this tutorial we will generate HUF data using T PROGS Using HUF arrays overcomes the main limitation of T PROGS The limitation is that grid cell dimensions must be kept small to capture the heterogeneity This results in thin cells at the top of the grid that are prone to wetting and drying problems With the HUF approach larger cell thicknesses can be used When using the HUF approach the user first creates a grid with constant row and column widths The layer elevations are then interpolated as desired to match aquifer boundaries When TSIM is executed in the HUF mode GMS creates a background grid that has the same dimensions as the primary grid in terms of rows and columns but has a greater number of layers than the primary grid resulting in greater detail or resolution in the vertical direction The background grid is then an orthogonal grid compatible with the T PROGS interpolation algorithm The T PROGS simulation is then performed on the background grid The heterogeneity resulting from the dense background grid is then translated by GMS into a set of grid independent HUF units 5 16 GMS Tutorials Volume I 5 6 1 5 6 2 5 6 3 5 6 4 Once again we will reuse the
82. n this tutorial and four different scatter point sets have been prepared in advance using the technique described above In the interest of time the files have already been imported to GMS and saved as a native GMS project To read in the project 1 Select the Open button a 2 Locate and open the directory entitled tutfiles layerdata 3 Select the file called points gpr and select the Open button Switch to Front View Before we interpolate we will change the view so that we are looking at a cross section of the grid That way we will immediately see the results of our interpolation Before switching the view we will first select a cell in the interior of the model Ifa cell is selected when switching views the new view will change to the row or column passing through the selected cell 1 Switch to the 3D Grid module ca 2 Select the Select Cell tool Ae 3 Select a cell near the middle of the grid 4 Select the View I Axis button g Notice the grid layers are flat interpolating the Elevation Values You should see a set of points appear on the screen The scatter point sets each have four data sets top1 botl bot2 and bot3 The next step is to interpolate each of these data sets to the appropriate layer in the MODFLOW array Before interpolating the points we need to initialize the MODFLOW data 1 Select the MODFLOW New Simulation command 7 4 7 6 GMS Tutorials Volume I 2 Select the OK button
83. nd throughout the entire model domain However we will adjust the layer thickness of the second layer so that the cells will be very small on the right side of the model thus simulating the pinchout Figure 7 2 Typical East West Cross Section Through Site with Embedded Seam 7 6 1 2D Geostatistics 7 5 Next we will interpolate the data from the scatter points for Case 2 The elevations for the second layer on the right side of the model are adjusted so that the bottom of layer 2 is ABOVE the top of layer 2 This overlap will be fixed after the values are interpolated 6 1 Interpolating the Values 7 6 2 To interpolate the values 1 Switch to the 2D Scatter Point module E 2 Make the Case 2 scatter point set the active set by selecting it in the Data Tree 3 Select the Interpolation to MODFLOW Layers command 4 Select the OK button Note how the middle layer becomes inverted on the right side of the model Correcting the Layer Data The next step is to fix the overlap on the right side of the model using the layer data tools in the MODFLOW model checker 1 Switch to the 3D Grid module 53 2 Select the MODFLOW Check Simulation command 3 Select the Run Check command 4 Scroll down to where the errors for the Basic package are shown Note that several layer elevation warnings are shown 5 Select the Fix Layer Errors button The Fix Layer Errors dialog provides several optio
84. nonccncnannnnononcononnana non nrncocononnnnanoss 3 6 3 9 1 Building Cross Section 7G 2G w cccccccccccseccsssescesesscesceseeseeseeseeseceeeecnsseecesesseeseeseeeeneveeeneeeseeaeereeaee 3 7 3 9 2 Building Cross Section SG OG ccccccccccssccsseescssesseescuseescesesseeseceeecseeececeeseeseeeeeeueseeenseeseeaeeseeaee 3 7 3 93 Building Cross Section 6G 8G cccccccccssscssssscssesscescnseesceseesesseeseesecaeesccsseeseeaessessecaeseecaeeeeeeaeeseaee 3 8 vi GMS Tutorials Volume I 3 10 VIEWING THE STRATIGRAPHY iii is 3 10 BT eA CONCLUSIONS iii ia 3 11 STRATIGRAPHY MODELING HORIZONS AND SOLIDS ccccnocnoonoonnoonnonnnonanonnocanoonnconaconoocnnononos 4 1 4 1 GETTING STARTED i233 ss2i8 scuedhiren dh esestt dados 4 1 4 2 REQUIRED MODULES INTERFACES ccccsscccssssesessescscssssssesesececsssesseseecscsesessesesesecsssesessesesecsasasanseseses 4 1 4 3 OVERVIEW nia ceive TN R A E O Acervo 4 2 4 4 READING BOREHOLE DATA SERE T EESE ANNET E ER 4 2 4 5 DISPLAYING THE HOLE NAMES oosist AEE A S n AE ERE EN E AEREA 4 2 4 6 ASSIGNING HORIZON IDS borai ae e rn EE os 4 3 4 6 1 Selecting Borehole Contact cccccceccccssccseescseeseeesseesecseeeecuseesenscnseesceseeseesecseeseceseecnseeseeaeeeeneets 4 3 406 2 Assigning Horizon ID LA A A A laos E ENER 4 4 4 6 3 Assigning Horizon ID cess secs ces ee Esse Sado OSS O aca 4 5 4 6 4 Assigning Horizon IDs 4 and Suc cccceccccccssessesceseeseesesscesecseveecseescuseesceecseeeceseeceseeseesecseeae
85. ns for correcting layer errors Notice that several errors are listed for layer 2 The correction options are shown on the left For this case we will use the Average option This method computes the average of the top and bottom elevation for each cell and moves the top elevation to be just above the average and the bottom elevation to be just below the average The final difference between the top and the bottom is set to the Minimum thickness value shown in the dialog 1 Select Layer 2 in the list on the right side of the dialog 2 Select the Average option 7 7 GMS Tutorials Volume I 3 Select the Fix Selected Layer button 4 Select OK to exit the Fix Layer Errors dialog 5 Select Done to exit the Model Checker dialog Note that the seam is now properly modeled It appears that the middle layer pinches out but in actuality it only becomes very thin and continues throughout the grid You may wish to use the arrow buttons in the Mini Grid Display to view the cross sections along other rows Case 3 Outcropping 7 7 1 The next case we will examine is shown in Figure 7 3 In this case the top layer is an outcropping that only exists on the left side of the model We will model this case using a three layer model and adjusting the thickness of the top layer so that it goes to a very small value on the right side of the model Figure 7 3 Typical East West Cross Section Through Site with
86. nt You can only enter steady state data this way To create a scatter point set with transient data you would need to import it from a file That s what we ll do next 7 Click OK to exit the Scatter Point Data Set Value dialog 6 4 Importing a Scatter Point Set Scatter point sets can be imported from an existing file using the Import Wizard The Import Wizard allows you to import data into GMS from text files that are in columnar format The file we will import was generated as an Excel spreadsheet and exported from Excel as tab delimited text The file contains scatter points which represent locations where the concentration of a contaminant has been estimated using a soil gas survey Our goal is to generate a map of the contaminant plume To read the scatter point file 1 Select the New button Ll and select No when prompted to save changes Error Reference source not found 6 3 2 Select the Open button lar 3 At the bottom of the Open dialog change the filter to Text Files txt 4 Locate and open the directory entitled tutfiles geos2d 5 Select the file entitled plumedat txt 6 Click on the Open button The Import Wizard should appear The first step of the Import Wizard allows you to specify how the data is delineated and where in the file the data begins For this file the first row contains column headings The first column contains the point labels the second column is the X values of the points the third
87. nted in the solid Horizons are numbered consecutively in the order that the strata are deposited from the bottom up Horizons are defined at borehole contacts interface between different materials on a borehole log Each contact that you wish to include in the construction of the solid must have a horizon ID A contact with a horizon ID of zero will be ignored which is the default value for each contact 4 1 Getting Started If you have not yet done so launch GMS If you have already been using GMS you may wish to select the File New command to ensure the program settings are restored to the default state 4 2 Required Modules Interfaces You will need the following components enabled to complete this tutorial 4 2 4 3 4 4 4 5 GMS Tutorials Volume I Sub surface characterization Mesh Grid Geostatistics Map You can see if these components are enabled by selecting the File Register Overview Creating a solid model of soil stratigraphy using the horizons approach in GMS is quite simple First we will read in a set of borehole data Second we will assign horizon IDs to the contacts of the boreholes Then we will create a TIN that will be used for interpolation and to define the boundary of our solid Finally we will execute the Horizons gt Solids command to create a set of solids Reading Borehole Data The first step in the construction of the solid models is to import a set of borehole log
88. ode all modules and interfaces are undimmed and functional regardless of which items have been licensed However all of the print and save commands are disabled The modules and interfaces needed for the tutorial are listed at the beginning of each tutorial While some of the tutorials may be completed in either normal or demo mode many of them can only be completed in normal mode If some of the required items have not been licensed you will need to obtain an updated password or hardware lock before you complete the tutorial Format Throughout the tutorials interface objects like menus or buttons are shown in italics Menu commands are given by specifying the menu followed by a symbol followed by the command like this Select the File Open command Values that must be entered by the user are given in bold like this Enter 2 0 for the Hydraulic conductivity CHAPTER 2 Surface Modeling With TINs The TIN module in GMS is used for general purpose surface modeling TIN is an acronym for Triangulated Irregular Network TINs are formed by connecting a set of xyz points with edges to form a network of triangles The surface is assumed to vary linearly across each triangle TINs can be used to represent the surface of a geologic unit or the surface defined by a mathematical function Elevations or other values associated with TINs can be displayed with contours TINs are used in the construction of solid models and 3D
89. oinciding with borehole locations will match the stratigraphy in the borehole log T PROGS 5 3 Materials Sand_wi_fines Zz Clay Clean_Sand y Sit X Figure 5 2 3D Oblique View of Borehole Data This tutorial will be completed in three phases In the first phase we will develop the input for a stochastic MODFLOW model using the LPF package and a 3D multi layer orthogonal grid In the second phase we will again use the LPF package but we will use a 2D single layer grid In the third phase we will use the HUF package with a 3D grid with non uniform layer elevations The second and third phases of the tutorial can be completed relatively quickly since we can re use the transition probability data developed during the first phase While this tutorial illustrates how to use the T PROGS interface to develop the input data for a stochastic MODFLOW simulation we will not actually run the MODFLOW simulation The steps involved in running a stochastic MODFLOW simulation using either the T PROGS approach or a Monte Carlo style approach are described in the Stochastic Modeling tutorial Volume II 5 2 Getting Started If you have not yet done so launch GMS If you have already been using GMS you may wish to select the File New command to ensure the program settings are restored to the default state 5 4 5 3 5 4 GMS Tutorials Volume I Required GMS Components You will need the following compon
90. olation Interpolation Options command Change the Horizontal anisotropy value to 2 0 Change the Azimuth value to 90 0 Select the OK button Select the Interpolation to 2D Grid command Enter c_idw_grad_h2 for the new data set name Select the OK button As can be seen the data has been stretched in the horizontal direction You might want to experiment with different values for the horizontal anisotropy 6 15 IDW Interpolation With Quadratic Nodal Functions The nodal functions used in IDW interpolation can also be quadratic functions which are constrained to pass through the scatter point and approximate the neighboring scatter points in a least squares fashion The averaging or blending of the quadratic functions during the interpolation stage often results in a very smooth surface 1 2 5 6 Select the Oblique View button tz Select the Interpolation Interpolation Options command Select the Options button to the right of the Inverse distance weighted option In the Nodal function section at the top of the dialog select the Quadratic option Select the OK button to exit the 2D IDW Interpolation Options dialog Select the OK button to exit the 2D Interpolation Options dialog To interpolate to the grid 7 8 Select the Interpolation to 2D Grid command Select the OK button 6 10 GMS Tutorials Volume I 6 16 Truncation Notice that the minimum value listed in the color legend i
91. olid cross sections so that the display is not so cluttered 1 2 Select the Select Cross Section tool AA Select the Edit Select All command Select the Hide button my Switch to the 3D Grid module ES Select the Display Options button a Generating MODFLOW Data From Solids 9 9 6 Turn on the Cell faces option and select Material for the Color 7 Select OK to exit the dialog The cells on the 3D grid should now be colored according to the material assigned to the grid cells Layer 1 of the grid is all green because all of the cells were assigned the material from the upper_aquifer solid 8 In the mini grid display select the down arrow to view the second layer Notice that the second layer has both silty clay blue and upper_aquifer green materials assigned to it Cycle through the other layers to see how the materials were assigned 9 Select the Select Cells tool Ae 10 Select a cell somewhere near the middle of the grid 11 Select the View J Axis button i 12 Use the arrow buttons Y A to view the grid along different rows 13 Select the View J Axis button ti 14 Use the arrow buttons in the Mini Grid Display to view the grid along different columns 9 7 Thin Cells The purpose of the Boundary Matching option for the Solids gt MODFLOW command is to ensure that each upper and lower boundary defined by the solid model is precisely matched by a layer boundary in the MODFLOW grid Asa re
92. represent the HUF units As you view the cross sections keep in mind that the vertical scale is currently magnified by a factor of 5 0 If you wish you can change back to the true scale using the Settings command in the Display menu This completes the HUF portion of this tutorial 5 20 GMS Tutorials Volume I 5 7 Conclusion This concludes the 7 PROGS tutorial Here are some of the key concepts in this tutorial e T PROGS can be used to help create single or multi layer MODFLOW model that uses the Material IDs approach with the LPF package It can also be used with the MODFLOW HUF package e You can perform a T PROGS simulation with or without borehole data CHAPTER 6 2D Geostatistics Two dimensional geostatistics interpolation can be performed in GMS using the 2D Scatter Point module The module is used to interpolate from sets of 2D scatter points to any of the other object types meshes grids TINs Several interpolation schemes are supported including kriging Geostatistics are useful for setting up input data for analysis codes or for site characterization The tools for manipulating scatter point sets and the interpolation schemes supported in GMS are described in this tutorial The interpolation schemes presented in this tutorial will be easier to understand if you have read the Interpolation section of the GMS Online Help This tutorial should be completed before attempting the 3D Geostatistics tutorial
93. rid 3 Select the View I Axis button 3 4 Select the View J Axis button fi Note how the bottom of the third layer the top of the bedrock cuts into the upper layers Correcting the Layer Values To correct the layer errors 1 Select the MODFLOW Check Simulation command 2 Select the Run Check command 3 Select the Fix Layer Errors button In this case a customized option called Truncate to bedrock is perfectly suited to our problem This method examines the elevations for each cell and if the bedrock elevation the bottom elevation for the bottom layer is above the top elevation of the cell the cell is made inactive If the bedrock elevation is below the top of the cell but below the bottom the bottom elevation is adjusted to match the bedrock elevation 1 Select the Truncate to bedrock option 2 Select the Fix Affected Layers button 3 Exit both dialogs Viewing the Corrected Layers Notice how the outcropping is now properly modeled To view the cross sections 1 Use the arrow buttons in the Mini Grid Display to view the grid along different columns 2 Select the View I Axis button El s 3 Use the arrow buttons f A to view the grid along different rows Next we will switch to plan view and see how the cells on the perimeter of the grid have been made inactive 7 10 GMS Tutorials Volume I 1 Select the View K Axis button amp 2 Use the arrow buttons f to view the grid on different laye
94. roject 1 Select the File Save As command 2 Change the name of the project to tprob3d gpr 3 Select the Save button As you continue with the tutorial you may wish to periodically save changes to the project using the Save command in the File menu or the Save button button Viewing the Borehole Data At this point you should see a set of boreholes and the grid frame displayed in plan view To view the heterogeneity in the borehole logs we will view the boreholes in oblique view 1 Select the Oblique View button tz Notice that the most common material at the site is clay and the least common material is clean sand It can also be seen that there is considerable heterogeneity at the site It should be noted that the current display has a z magnification factor of 5 0 This factor can be adjusted using the Display Settings command To return to plan view 2 Select the Plan View button taeu 5 6 GMS Tutorials Volume I 5 4 4 Building the 3D Grid Before editing the T PROGS data we must first create the 3D grid For sites such as this one where the grid must be rotated to align it with the regional ground water flow direction the best approach is to use the grid frame to define the grid location The grid frame is located in the Map Module of GMS and is used to define the location size and orientation of the grid To create the grid frame 1 Switch to the Map module 2 Select the Feature Objects New Grid
95. ross Sections 7G 2G 5G 6G and 6G 8G Next we will build cross sections 7G 2G 5G 6G and 6G 8G Since the two boreholes in each of these three cross sections do not match each other in the sequence of borehole regions we have to manually create all the arcs needed to Stratigraphy Modeling Boreholes and Cross Sections 3 7 delineate the soil layers Then we will use the Build command to build the polygons representing soil layers 3 9 1 Building Cross Section 7G 2G 1 Double click on 7G 2G s icon to bring up the Cross Section Editor 2 Select the Create Arc tool Gr 2G 7G A E B F G Figure 3 4 Cross Section 7G 2G 3 Create all the arcs shown in Figure 3 4 4 Select the Build button 5 Select the OK button 3 9 2 Building Cross Section 5G 6G 1 Double click on 5G 6G s icon to bring up the Cross Section Editor 2 Select Create Arc tool E 3 8 GMS Tutorials Volume I 56 6G D A E F B c Figure 3 5 Cross Section 5G 6G 3 Create all the arcs shown in Figure 3 5 Note that the arc starting at contact C ends about half way between the two boreholes at point G 4 Select the Build button 5 Select the OK button 3 9 3 Building Cross Section 6G 8G Up to this point in the tutorial we have just created straight lines between boreholes Now we will create a more detailed cross section First we will read in a TIN that defines the surface elevation for
96. rs Finally we will view the grid in general mode to see a 3D plot of the stratigraphy 1 Select the Display General Mode command 2 Select the Oblique View button tz A You may wish to use the Rotate tool to view the grid from different viewpoints 7 9 Conclusion This concludes the nterpolating Layer Data tutorial Here are some of the key concepts in this tutorial e You can interpolate from 2D scatter points directly to MODFLOW elevation data arrays e Interpolating to MODFLOW elevation data can result in layers that overlap e You can correct overlap errors by using the Fix Layer Errors dialog available via the MODFLOW Check Simulation command e There are different ways to fix layer errors and you can pick the method that best suits your particular problem CHAPTER 8 3D Geostatistics Three dimensional geostatistics interpolation can be performed in GMS using the 3D Scatter Point module The module is used to interpolate from sets of 3D scatter points to 3D meshes and 3D grids Several interpolation schemes are supported including kriging Interpolation is useful for defining initial conditions for 3D ground water models or for 3D site characterization The tools for manipulating 3D scatter point sets and the interpolation schemes supported in GMS are described in this tutorial Before attempting this tutorial you should have completed the 2D Geostatistics tutorial 8 1 Getting Started If
97. rthermore a T PROGS simulation can be performed without borehole data In such a case the user would define the mean proportions and lens lengths for each material This option is described in more detail in the GMS Help File The second column in the top section of the dialog lists the background material By default the material type that had the predominant occurrence in the boreholes greatest proportion is marked as the background material When defining the transition probability data in the next section the input parameters do not need to be edited for the background material The parameters for this material are automatically adjusted to balance the equations To proceed to the next step 3 Select the Next button 5 8 GMS Tutorials Volume I 5 4 6 Developing the Vertical Markov Chains The most important step in setting up the T PROGS data is to define the transition probability data for each material located in the boreholes in the three primary directions vertical strike and dip The vertical transition trends are developed first based on the borehole data The data in the strike and dip directions can then be derived from the vertical data The first step in setting up the transition data is to run a utility within T PROGS called GAMEAS that computes a set of transition probability curves as a function of lag distance for each material for a given sampling interval GAMEAS is launched as follows 1 Select the
98. s Borehole data can be entered into GMS manually or the data can be read from a file In the interest of time we will read in a previously prepared file To read in the file 1 Switch to the Borehole module Y 2 Select the Open button gt 3 Locate and open the directory entitled tutfiles horizons 4 Select the file entitled holes gpr 5 Click on the Open button You should now see a 3D view of the borehole logs Each of the colors represents a different type of soil The green soil is a clean sand the red soil is a silty sand and the blue soil is a silty clayey fine sand For the remainder of this tutorial the soils will be referred to by their colors for simplicity Displaying the Hole Names To help distinguish between the holes on the screen the names of the holes will be displayed on the holes Stratigraphy Modeling Horizons And Solids 4 3 1 Select the Display Options button a 2 Turn on the Hole Names option 3 Select the OK button The names of the holes should appear at the tops of the holes These names were defined in the borehole file 4 6 Assigning Horizon IDs The next step in the construction of the stratigraphy model is to assign the horizon IDs to the borehole contacts 4 6 1 Selecting Borehole Contacts We need to select a group of borehole contacts and set the horizon ID The first horizon we will define will be for the top of the lower silty clay red layer 1 Select the Select Conta
99. s a negative number Of course this is impossible since there is no such thing as a negative concentration By inferring trends the nodal functions can sometimes project the plume values beyond zero and into the negative range This type of error can be easily fixed using truncation 1 Select the Interpolation Interpolation Options command 2 Turn on the Truncate values option 3 Select the Truncate to specified range option 4 Enter 0 0 for the min value and enter 150 0 for the max value 5 We don t want the concentrations to go below zero but we will allow the interpolation scheme to infer a maximum concentration greater than the maximum measured value 6 Select the OK button To interpolate to the grid 7 Select the Interpolation to 2D Grid command 8 Enter c_idw_quad_trunc for the name of the new data set 9 Select the OK button Notice that the concentrations are now mostly zero around the perimeter of the map 6 17 Natural Neighbor Interpolation Next we will use natural neighbor interpolation Natural neighbor is similar to IDW interpolation in that it is a moving weighted average approach However the technique used to compute the weights in natural neighbor interpolation is based on topological relationships rather than distance alone This approach tends to provide good results even when the scatter points are clustered 1 Select the Interpolation Interpolation Options command 2 Select the Natural ne
100. s for the top of the grid Although we could also interpolate the elevations at the bottom of the grid we will leave these values at a constant value for simplicity We will then use the Redistribute Layers command to evenly distribute the elevations for the interior layer boundaries Importing the Scatter Point Data We will import the scatter data from a tabular text file 1 Select the Open button a 2 Inthe Files of type combo box at the bottom of the Open dialog select the Text Files txt filter 3 Select and open the file topo txt 4 Turn on the Heading row toggle in the first page of the File Import Wizard 5 Select the Next button 6 Confirm that the GMS data type selection at the top of the dialog is 2D Scatter Points 7 The spreadsheet at the bottom of the dialog enables you to specify what types of data are in each column In the Type row make the elevation column fourth column a Data set type This indicates that the fourth column represents an elevation data set 8 Select the Finish button A set of scatter points should appear in the vicinity of the grid Interpolating the Layer Elevations Next we will interpolate the elevations associated with the scatter point set to the top of the MODFLOW grid using the default interpolation options 1 Switch to the 2D Scatter Point module e 5 18 GMS Tutorials Volume I 5 6 6 4 Select the Interpolation to MODFLOW Layers command In the
101. s of the scatter points on the perimeter of the scatter point set are zero 6 10 Viewing the Elliptical Control Function The scatter points were generated from an elliptical control function It s interesting to see how the different interpolation schemes compare to the original control function To view the original control function a 1 Select the Open button 2 Change the Files of type to All Files 3 Select the file tutfiles geos2d ellipse2g dat and click Open 6 11 Clough Tocher Interpolation Next we will try Clough Tocher interpolation Error Reference source not found 6 7 Switch to the 2D Scatter Point module 1 Select the Interpolation Interpolation Options command Select the Clough Tocher option Select the OK button To interpolate to the grid 5 6 Select the Interpolation to 2D Grid command Select the OK button Once again interpolation was only performed within the convex hull of the scatter point set As with linear interpolation the first step in Clough Tocher interpolation is to triangulate the scatter point set to form a temporary TIN However rather than performing a linear interpolation of each triangle a cubic surface patch is fitted over each triangle and the cubic patches are used in the interpolation 6 12 Simple IDW Interpolation The next scheme we will try is a simple form of inverse distance weighted IDW interpolation 1 2 6 7 Select the
102. s option is the simplest to use With this option a curve fitting process is used to adjust the transition rates and proportions so that the curve coincides exactly with the measured transition probability at the selected lag interval By adjusting the lag interval an excellent fit can often be obtained We will use this option to fit our curves and proceed to the next step 10 Enter 17 for the Lag and select the Tab key This number produces a good fit between the measured transition data and the Markov Chains 11 Select the Next button Define the Strike Dip Transition Trends The next step is to define the Markov Chains in the strike and dip directions In theory the GAMEAS utility could be run in the strike and dip directions to develop measured transition probability data which could then be modeled with Markov Chains However borehole data are not sufficiently dense in these directions to develop meaningful data Therefore we apply Walther s Law to develop the strike and dip Markov Chains Walther Law states that vertical successions of deposited facies represent the lateral succession of environments of deposition In other words the transition rates in the horizontal directions can be derived from the transition rates in the vertical direction To begin with we can assume that the proportions are the same in all three directions The Lens length ratios method is then used to define the transition rate matrix With this method t
103. snteesenaeets 4 6 4 6 3 Displaying the Horizon ID Suicidal at bons dc dano ri 4 7 4 7 CONSTRUCTING THE TIN oair EE T a A ao 4 7 ATA Suing Up the COVErA RC essere 8 a diia 4 8 4 7 2 Creating the Boundary Polygon c ccccsccccesccssesseesetseesseetseeeecseescuseescenecseeecseecceeseeaeeseeesneeeeeeeets 4 8 NN Y NIN ios E E E A 4 9 4 8 CREATING THE SOLIDS omita 4 9 4 8 1 Viewing theSolldS erenn eaen a tdi edil 4 10 4 8 2 Cutting Cross SCCHONS comisionista neste cok ies E aE EEE EEEE EEEE EE EEE 4 10 4 8 3 Modeling Pinchout c ccccccsccesesscesesseesecsseeecseescsesseesecseesecaceeccesesseesecsessecaeeeceseeeeeaesseeseceeeeenaes 4 11 4 8 4 Cutting Cross Sections A innn i e eeii iere i e a neies 4 14 4 8 5 Using Borehole Cross Section Data i ccccccccecccccssecssescsesscesenseescesesseeeceseecnseesceseeseeseseseecnseesenaes 4 14 4 9 CREATING HUF DATA FROM HORIZONS oopen inane R A desecaci n 4 16 AQT Reading NEST Grid a i aa a A a vee E EEEE 4 16 4 9 2 Initializing MODFLOW 2000 and HUF Data eeeerrsreerrerrisrsrierrennes 4 17 4 9 3 Horizons 10 HUE imaisee e a E A A aa E aa Deed ENa AEE n ia s 4 17 4 9 4 Viewing the HUF Data A adan ae iodo 4 17 ATO A enose aa raa aE E RA KERE Ea Eae Aa KEE E a NS 4 18 a A O 1 GS PET A E S I E E E candcnodeide s 5 1 5 1 PROBEEM DESCRIPTION ii A reat eee ae teea ess 5 1 5 2 GETTING STARTED serienn tac nina NO EDO cutee nase age tans Heese ane AA 3 3 38 REQUIRED GMS COMPONENTS aincoa E E T A E S
104. sult of this approach thin cells often occur where solids pinchout If you want to limit the effect of the thin cells in your model grid you can set a target minimum thickness for each of the solids 9 10 GMS Tutorials Volume I 9 7 1 9 7 2 Figure 9 6 Row 30 of Model Grid After Executing Solids gt MODFLOW Figure 9 6 shows a row of the model grid after running Solids gt MODFLOW Notice the thin cells that you get on the edges of the clay yellow and silty clay blue solids 1 Select the View I Axis button El 2 Use the arrow buttons f A to move the current grid row to 30 The grid should look similar to Figure 9 6 Assigning Minimum Thickness Now we will use the Target minimum thickness to limit the thin cells in our model 1 Switch to the Solids module YY 2 Double click on the upper aquifer 1 solid in the Data Tree 3 Change the Target min cell thickness to 20 and select OK to exit the dialog 4 Repeat these steps for all of the remaining solids Top Cell Bias Another problem that may be encountered using the Boundary Matching option is that the cells in the top layer of the grid may also be too thin and subject to wetting and drying To ensure that the top layer of your grid is sufficiently thick you can use the Top cell bias option Generating MODFLOW Data From Solids 9 11 1 Double click on the upper_aquifer 1 solid in the Data Tree 2 Change the option next to Use top cell
105. t MODELO Walt titi rat ta ida lali 9 8 9 6 VIEWNG THE AR o so 9 8 9 7 THN CELL Saian kr KEE E EE Aa 9 9 9 7 1 Assigning Minimum Thickness ccccccccceccsseescesesseesetseesecseesecnseescesecseesecsessecnesescseeseesesseeeseeeteas 9 10 QTD TOP C e S o a A erda ea E eoa vs wih Mien dat e aa 9 10 9 8 CONVERTING THE CONCEPTUAL MODEL cccssssseesssscecessaeeecesececeeueeecsesaeeeceeeeeesesaeeecsesaeeseneeeeeeea 9 11 9 8 1 Using Materials to Define Hydraulic conductivity 9 12 9 9 RUNNING MODELO Wisin e eee nea 9 12 9 10 SODS AA NON 9 13 9 10 1 Selecting the HUF Package cccccsccsssssssssessesecscesscceecceseessesecacesecsceceeaeneesecaseceeaecaeesseneeees 9 13 9 10 2 Converting the Solids to HUF Data i ccccccccsccscsscesesseesetseesecseeeeeecueeeecnseescnsesseesestevaesneeeeenaeets 9 14 9 10 3 Viewing the HUF Dt xa cs crc t ess aletas 9 14 9 10 4 Converting the Conceptual Model cccceccccssscssseesesseeecnseescusecseeseceeecaseesesesseeseseeeenteeeenatens 9 15 9 10 5 Running MODEL OW 0 A A E 9 15 Table of Contents ix 9 11 CONCLUSION esti O coves secu Sodas Behe dd de A eee sn 9 15 CHAPTER 1 Introduction This document contains tutorials for the Department of Defense Groundwater Modeling System GMS Each tutorial provides training on a specific component of GMS Since the GMS interface contains a large number of options and commands you are strongly encouraged to complete the tutorials before attempting to use GM
106. t of the Inverse distance weighted option In the Nodal function section at the top of the dialog select the Constant option In the section entitled Computation of interpolation weights select the Use subset of points option Select the Subset button in the Computation of interpolation weights section Select the Use nearest points option and enter 64 for the number of points Select the OK button to exit the Subset Definition dialog Select the OK button to exit the IDW Interpolation Options dialog 10 Select the OK button to exit the Interpolation Options dialog To interpolate to the grid l Ze Select the Interpolation to 3D Grid command Select the OK button 8 8 Displaying lso surfaces Now that we have interpolated to the nodes of the 3D grid there are several ways to visualize the contaminant plume One of the most effective ways is to use iso surfaces Iso surfaces are the three dimensional equivalent of contour lines An iso surface represents a surface of a constant value contaminant concentration in this case To define and display iso surfaces 1 2 Switch to the 3D Grid module p Select the Display Options button a 3D Geostatistics 8 5 3 Turn off the Cell edges option and turn on the Grid shell and Iso surfaces options 4 Select the Options button to the right of the so Surfaces option 5 On the first row enter 3000 0 for the Upper Value 6 On the second row
107. tcroppings the scatter point data must be defined carefully Once interpolated the scatter point data may result in overlapping layers These errors can be automatically corrected using the Model Checker Sample Problems To illustrate the process of interpolating the elevations and fixing errors we will look at a series of example problems Each example problem illustrates a different problem and describes a simple approach for correctly modeling the stratigraphy Case 1 Complete Layers The first case we will examine is shown in Figure 7 1 This is the simplest of the cases examined in this tutorial The site has three layers and all three layers extend over the entire domain of the model A Figure 7 1 Typical East West Cross Section For Case 1 7 5 1 7 5 2 7 5 3 2D Geostatistics 7 3 Importing the Scatter Point Sets The first step in defining the layer data is to create a grid The next step is to create a set of points at various xy locations in the model Each point has an elevation for the top and bottom of each layer In a real problem these data would come from sources such as exploratory boreholes The data are entered into a tabular text file typically through the use of a spreadsheet such as Microsoft Excel Then the Import Wizard is used to import the tabular text file into GMS The 2D Geostatistics tutorial teaches how to do this in detail We will look at 4 different scenarios i
108. te description of the triangulation algorithm can be found in the GMS Online Help 2 5 Contouring Now that the TIN is constructed we can use it to generate a contour plot of the TIN elevations 1 Select the Display Options button a 2 Turn on the Contours and TIN Boundary options and turn off the Triangle edges and Vertices options 3 Select the OK button The contours are generated by assuming that the TIN defines a surface that varies linearly across the face of each triangle 2 6 Lighting Surface Modeling With TINs 2 3 Another way to visualize a TIN is to use a light source 1 2 Select the Display Options button a Turn off the Contours and TIN Boundary options and turn on the Triangle faces option Select the OK button Select the Oblique View button ky Select the Display Lighting Options command Change the Ambient Light to 0 7 and click OK E A Select the rotate tool and drag the mouse in the graphics window to rotate the view 2 7 Editing TINs As TINs are used in the construction of solids and meshes it is usually necessary to edit a TIN once it has been created In many cases TINs are constructed from a sparse set of points and it is necessary to fill in the gaps between the vertices and sculpt the TIN using the editing tools to ensure that the TIN is a reasonable representation of the surface being modeled A variety of tools are provided in GMS for editing TINs Before revie
109. the borehole data by the GAMEAS utility In general this curve represents the transition probability from material j to material k The transition probability t h is defined by tal Pr j occurs at x h k occurs at Decora italia 5 1 T PROGS 5 9 where x is a spatial location h is the lag separation vector and j k denote categories The lag is defined by the Lag spacing item in the upper left corner of the Vertical Markov Chains dialog The curve shown with the solid line is called a Markov Chain The Markov Chains are used to formulate the equations used by T PROGS to generate the multiple material sets during the simulation stage The objective of this stage of the analysis is to fit the Markov Chain curves as accurately as possible to the measured transition probability curves This process is similar to fitting a model variogram to an experimental variogram in a kriging exercise Mathematically a Markov chain model applied to one dimensional categorical data in a direction y assumes a matrix exponential form T hg exp Rho nace nece senensacsceaeseaseoaceeeeseencnssenessesissecesiceesscesssneees 5 2 where denotes a lag in the direction q and Ry denotes a transition rate matrix Pao Pro R r A y k1 kk 53 with entries 7g representing the rate of change from category j to category k conditional to the presence of j per unit length in the direction q The transition rates are adjusted to ensure a good fit be
110. the relationship 1 Tag S E Beien e ee Gis se A e Ia 5 6 kp where L is the mean lens length The off diagonal terms represent the ratio of the current transition rate to the transition rate corresponding to maximum entropy When this factor is equal to 1 0 the probability that a given material is adjacent to another material is consistent with a random distribution of the materials In other words the probability will be dependent only on the proportions of the two materials Viewing these factors illustrates the juxtapositioning tendencies in the borehole data For example the Silt gt Clean Sand factor in the Silt row and the Clean Sand column should be equal to 0 39 This factor represents the transition from silt to clean sand moving in the Z upwards direction The Clean _Sand gt Silt factor is 1 01 5 4 7 T PROGS 5 11 With factors less than 1 0 we can conclude that the type of transition occurs less frequently than one might expect given the proportions of the materials Since the Clean Sand gt Silt factor is greater than the Silt gt Clean Sand factor we can conclude that it is less likely to transition from Silt to Clean_Sand than from Clean_Sand to Silt when moving in the Z direction In other words these two materials exhibit a fining upwards tendency The maximum entropy factors provide a simple and intuitive way to view and edit the transition rates 9 Select the Fit curves to a discrete lag option Thi
111. this site 1 Select the Open button as 2 Locate and open the directory entitled tutfiles horizons 3 Change the filter to All Files 4 Select the file entitled top_elev tin You should now see a TIN in the graphics window 9 Stratigraphy Modeling Boreholes and Cross Sections 3 9 Now double click on 6G 8G s icon to bring up the Cross Section Editor Select the Select Arc tool E Select the top arc on the cross section and select the Redistribute button In the Spacing edit field enter 25 This will create vertices along the arc at intervals of 25 feet Select the OK button to exit the Redistribute dialog We will now use the TIN that was read in to adjust the elevations of the vertices we just created 10 Select the top arc on the cross section again and select the TINs gt 4Arcs button 11 Select the top elevation TIN and select OK to exit the dialog Notice that the locations of the vertices of the top arc have now changed and match the elevations from the TIN 12 Select Create Arc tool i 3 10 GMS Tutorials Volume Figure 3 6 Cross section 6G 8G 13 Now create the other arcs shown in the figure above 14 Select the Build button 15 Select OK to exit the dialog 3 10 Viewing the Stratigraphy You re now done building the cross sections To view the site s soil stratigraphy represented by the set of cross sections you built 1 Switch to the TIN
112. to green 4 In a similar manner rename material 2 to Silty_or_Clayey Fine Sand and change its color to blue 5 Also rename material_4 to Silty_Clay and change it s color to red 6 Click OK 3 6 Creating Blank Cross Sections The next step is to create a set of blank cross sections interactively using the mouse The set of cross sections will be blank because at this point we are indicating where the cross section should be not what it should look The blank cross sections will appear as two lines connecting the tops and bottoms of the two boreholes For this tutorial a borehole cross section created between two boreholes will be named by the combination of the two holes names For example a cross section created between holes 1G and 7G will be named as 1G 7G The set of blank cross sections we will create are 1G 7G 7G 2G 2G 5G 4G 5G 5G 6G 6G 7G 3G 6G and 6G 8G 1 Select the Create Cross Section tool AA 2 Create the first set of cross sections by clicking on hole 1G to begin then single clicking on hole 7G 2G 5G 6G in sequence and double clicking on hole 8G to end 3 Create cross sections 3G 6G and 6G 7G by clicking on hole 3G to begin then single clicking on hole 6G and double clicking on hole 7G to end 3 4 GMS Tutorials Volume I 4 Create cross section 4G 5G by clicking on hole 4G to begin and double clicking on hole 5G to end The blank cross sections should look like those in th
113. ton O 2 8 2 2 8 3 2 8 4 Surface Modeling With TINs 2 7 2 Select No to avoid saving the changes 3 Select the Open button a 4 Select the file entitled sparse gpr 5 Click on the Open button Copying the Vertices The first step in smoothing the TIN is to copy the vertices of the TIN to a scatter point set This will allow us to use the scatter point set later to interpolate the z values of the original vertices to the new vertices created while subdividing the TIN 1 Select the Build TIN TIN gt 2D Scatter Points command 2 Select the OK button to accept the default name of the new scatter point set 3 Select the No button to indicate that you do not want to delete the existing TIN Subdividing the TIN The next step is to increase the resolution of the TIN by uniformly subdividing the TIN 1 Select the Modify TIN Uniformly Subdivide TIN command 2 Move the scroll bar to select a subdivision factor of 8 3 Select the OK button Interpolating the Elevations Notice that the contours of the TIN have not changed There are more triangles in the TIN but they still define essentially the same surface To smooth the TIN we must use one of the interpolation schemes and interpolate from the original vertices of the TIN to the new vertices created during the subdivision process 1 Switch to the 2D Scatter Point module ml 2 Select the Interpolation Interpolate gt Active TIN command we will use t
114. turn on the Fill between option 7 Turn on the so surface faces option 8 Select the OK button to exit the Iso Surface Options dialog 9 Select the OK button to exit the Display Options dialog You should now see the iso surface 8 9 Interior Edge Removal A series of edges are draped over the iso surface plot These edges represent the intersection of the iso surface with the grid cells The edges are displayed to help the user visualize the spatial variation or relief in the iso surface However it is sometimes useful to inhibit the display of the edges in some areas For example in the regions where the plume intersects the grid the iso surface is flat We will turn off the display of the edges in this area since they provide little benefit 1 Select the Data Iso Surface Option command 2 At the bottom of the dialog select the Interior edge removal option This removes the edges between adjacent planar facets that are coplanar 3 Select the OK button 8 10 Specified Range You may have noticed that the shell of the iso surface is all one color but the interior of the iso surface where the iso surface intersects the boundary of the grid varies in color according to the contaminant concentration We can change the display options so that the color variation in this region is more distinct 1 Select the Data Iso surface Options command 2 Select the Contour specified range option 8 6 GMS Tutorials Vo
115. tween the Markov Chain model and the observed transition probability data It should be noted that the self transitional curves on the diagonal start at a probability of 1 0 and decrease with distance and the off diagonal curves start at zero probability and increase with distance In both cases the curves eventually flatten out at some distance The probability corresponding to the flat part of the curve represents the mean proportion of the material All curves on a particular column should flatten out to the same proportion The proportions are displayed in the lower left corner of the dialog As expected clay has the highest proportion of the four materials The point where a tangent line from the early part of the curves on the on the diagonal intersects the horizontal lag distance axis on each curve represents the mean lens length for the material The mean lens lengths are shown just to the right of the mean proportions in the lower left part of the dialog The slope at the beginning of each of the Markov Chains represents the transition rate Together the proportions lens lengths and transition rates define the Markov Chains Several methods are provided for fitting the Markov Chains to the measured transition probability curves These methods are listed in the section of the dialog titled Markov Chains By default GMS automatically makes an attempt to fit the curves using the Edit maximum entropy factors option In many cases th
116. wing these tools we will reset some of the display options 1 2 Select the Display Options button a Turn on the Vertices and Contours options Select the Options button to the right of the Contours option In the section titled Contour Interval select the Specified Interval option and change the interval to 20 0 Select the OK button to exit the Contour Options dialog Select the OK button to exit the TIN Display Options dialog 2 4 GMS Tutorials Volume I 2 7 1 2 7 2 2 7 3 Dragging Vertices One of the simplest ways to edit a TIN is to drag the vertices with the mouse This can be accomplished with the Select Vertices tool 1 From the Tool Palette choose the Select Vertices tool oh 2 Select the Plan View button 2m 3 Choose one of the vertices in the interior of the TIN and drag it to a new location Notice that you are not allowed to drag an interior vertex beyond the boundaries of the adjacent triangles This prevents the triangles from becoming inverted Dragging in Oblique View When dragging in plan view the vertex is constrained to move in the xy plane To change the z coordinate we must drag the vertices in oblique view or front or side view 1 Select the Oblique View button tz 2 Select one of the vertices and drag the vertex up and down Notice that as you drag the vertex in oblique view you are constrained to move the vertex along the z axis Using the Edit Window In man
117. xecuted each cell is compared to the corresponding unit elevation arrays and equivalent hydraulic properties are assigned to the cell The figure below shows an example of HUF units on a MODFLOW grid Figure 9 8 HUF Data 9 10 1 Selecting the HUF Package First we need to select the HUF package as our flow package 1 Select the MODFLOW Global Options command 2 Select the Packages button 3 In the Flow Package section of the MODFLOW Packages dialog change the flow package to Hydrogeologic Unit Flow HUF 4 Select OK twice to exit both dialogs 9 14 GMS Tutorials Volume I 9 10 2 Converting the Solids to HUF Data We are now ready to convert the solids to HUF data However when we ran the Solids gt MODFLOW command some of the cells were inactivated in layers 4 and 5 We want those cells to be active for this new model N 1 Switch to the Map module 2 Select the Feature Objects Activate Cells in Coverage s command 3 Switch to the Solids module 4 Select the Solids Solids gt HUF command 5 Turn on the Adjust grid cell elevations toggle This toggle results in the grid elevations matching the topology of the solids The MODFLOW top elevation array of the top layer and the bottom elevation array of the bottom layer are adjusted to match the union of all the solids The interior top and bottom elevation arrays are assigned based on the proportions entered in the Elevation bias spreadsheet The
118. y cases dragging vertices with the mouse is not adequately precise It is often necessary to change the vertex coordinates to a specific value This type of editing can be accomplished with the input fields at the top of the GMS window 1 Click on any one of the vertices to select it Notice that as the vertex is selected the coordinates of the vertex are displayed in the fields at the top of the window The edit fields can be used to change the x y or z coordinates of the selected vertex 2 Move the cursor to the z coordinate field and enter a value that is 5 more than whatever the current z value is 3 Hit the Return or Tab key 2 7 4 2 7 5 Surface Modeling With TINs 2 5 Again as the vertex coordinates change the triangle edges are immediately updated Locking Vertices In many cases some of the vertices defining a TIN come from actual measured data such as a borehole log and can be considered hard data In other cases vertices are added manually and represent soft data used simply to fill in gaps When editing a TIN it is useful to distinguish between these two types of vertices so that a vertex corresponding to an actual measurement is not accidentally edited This can be accomplished by locking and unlocking vertices 1 Select several vertices by dragging a box around the vertices or by clicking on individual vertices while holding down the Shift key 2 Select the Modify TIN Lock Unlock Vertices com
119. y from horizon data CHAPTER 5 T PROGS This tutorial describes how to use the T PROGS interface in the Borehole Module of GMS T PROGS is a software package that performs transition probability geostatistics to generate multiple equally probable models of aquifer heterogeneity all of which can be conditioned to borehole data T PROGS is generally used in a stochastic modeling approach with the MODFLOW model T PROGS can be used to generate multiple material sets used in the new Layer Property Flow LPF package in MODFLOW 2000 T PROGS can also be used to generate multiple instances of HUF data used in the new Hydrogeologic Unit Flow HUF package in MODFLOW 2000 This tutorial will demonstrate the application of T PROGS in generating material sets for both a multiple layer grid and a one layer grid In addition this tutorial will demonstrate how to generate multiple sets of HUF data T PROGS was originally developed by Graham Fogg and Steven Carle at UC Davis For more information consult the T PROGS User Manual Carle Steven F T PROGS Transition Probability Geostatistical Software Version 2 1 Hydrologic Sciences Graduate Group University of California Davis 1999 5 1 Problem Description The problem we will be modeling in this tutorial is illustrated in Figure 5 1 The objective is to set up a stochastic simulation for a local scale model of a site in Texas The grid for the local scale model will be oriented in the general d

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