User`s Manual for OpenNSPECT, Version 1.1
Contents
1. DEM Grid CANSPECTAHI_Sample_DatasHI_dem_30 tif Units F Hpdroloaically Corrected DEM Subwatershed Size small y Watershed C NSPECT wesdelin H _SamplewS basinpoly shp Flow Accumulation Grid C NSPECT wsdelin HI_SamplewS flowacc tif LS Grid C NSPECT wsdelin HI_SamplewS Isa Watershed Delineation Name This field contains all the currently defined watershed delineations within OpenNSPECT Fields in the Watershed Delineations window are populated according to the selected watershed delineation name DEM Grid The DEM Grid field provides topography data for use in OpenNSPECT analyses and is automatically populated with the DEM grid defined for the selected watershed delineation This field cannot be edited The tool was developed and tested using 30 meter DEMs from the U S Geological Survey USGS although other DEMs may also be used USGS DEMs are available for download at http data geocomm com dem demdownload html Note Care must be taken to ensure that the grid cells of the DEM and land cover data sets and all other grid data sets match See the OpenNSPECT technical guide for more information Units This field is automatically populated with the DEM grid units meters or feet defined for the selected watershed delineation This field cannot be edited in this window Hydrologically Corrected DEM Select the Hydrologically Corrected DEM check box if you have already hydrologically correct2. Hydrologic Soil Group Definitions Hydrologic Soil Group Soil Group Characteristics Soils having high infiltration rates even when thoroughly wetted and A consisting chiefly of deep well to excessively drained sands or gravels These soils have a high rate of water transmission Soils having moderate infiltration rates when thoroughly wetted and consisting chiefly of moderately deep to deep and moderately fine to B moderately coarse textures These soils have a moderate rate of water transmission Soils having slow infiltration rates when thoroughly wetted and consisting c chiefly of soils with a layer that impedes downward movement of water or soils with moderately fine to fine texture These soils have a slow rate of water transmission Soils having very slow infiltration rates when thoroughly wetted and consisting chiefly of clay soils with a high swelling potential soils with a D permanent high water table soils with a claypan or clay layer at or near the surface and shallow soils over nearly impervious material These soils have a very slow rate of water transmission K Factor Attribute Select the attribute in the soils data set that corresponds to the K factor The K factor kffact is an attribute found in the chorizon table of the SSURGO database This factor is derived from the amount of soil lost per unit of erosive energy in the rainfall assuming a standard research plot It is an erodibility
3. New Precipitation Scenario dialog New Precipitation Scenario E x Enter new scenario information Scenario if Description P Precipitation Grid P El Grid Units py Precipitation Units A Time Period y Te Caro Scenario Provide a name for the new precipitation scenario being added limit of 35 characters Description Provide a brief description less than 100 characters of the new precipitation scenario 23 Precipitation Grid Use the browse button to select the precipitation grid to associate with this precipitation scenario Grid Units Specify the cell size units meters or feet of the specified precipitation grid This information may be found in the metadata for the precipitation data set Precipitation Units Specify the precipitation units centimeters or inches that are reported in the precipitation grid This information may be found in the metadata for the precipitation data set Time Period Specify the type of precipitation scenario annual or event depending on the type of precipitation data you are using Different methods will be used to estimate soil erosion from annual precipitation data than from event based precipitation data To avoid confusion your scenario name should accurately reflect the time period you have chosen Type Specify the rainfall type in the analysis region The different rainfall types describe the four synthetic 24 hour rainfall distributions develop
4. and choose Export from the Options menu Name the exported file and designate a location in which to save the file The land cover classes are written to a comma separated ASCII file containing a row of values for each land 16 cover class The file contains a header row with the name of the land cover type and the description Each row contains seven fields ordered as follows Value name Curve A Curve B Curve C Curve D CoverFactor Wet 3 2 Pollutants The primary focus of OpenNSPECT is nonpoint source pollutants OpenNSPECT applies coefficients representing the expected pollutant load from each land cover type to approximate total nonpoint source pollutant loads The accuracy of OpenNSPECT s pollutant results depends on these coefficients To apply the tool to other areas you should develop coefficients based on local data when possible Use the Pollutants dialog box to view or edit information about previously defined pollutants to define new pollutants or to delete pollutants that are no longer needed Use the Pollutants menu to add or delete a pollutant Use the Coefficients menu to create copy delete import or export a coefficient set View or Modify Pollutant To modify an existing pollutant select Advanced Settings and Pollutants Select the pollutant of interest in the Pollutant Name drop down list The list will display all the currently defined pollutants within OpenNSPECT Fields in the Pollutants window are populate
5. box in the Apply column To exclude a pollutant from the analysis clear the check box The column defaults to cleared which means that the pollutant in that row will not be included in the analysis Pollutant Name The Pollutant Name column is automatically populated with the name of all the currently defined pollutants and cannot be edited in this window see Advanced Settings gt Pollutants to learn how to add a pollutant Coefficient Set Select the appropriate coefficient set for the pollutant from the drop down list of all currently defined coefficient sets for that pollutant see Advanced Settings gt Coefficients to learn how to add a coefficient set Which Coefficient Select the coefficient type Type 1 Type 2 Type 3 or Type 4 to be used to run the analysis OpenNSPECT will apply that coefficient type to each land cover class in the area of interest If only one type of coefficient is available select Type 1 Once the pollutants are specified and the other parameters in the project setup window are selected the analysis can be run by pressing the Run button in the bottom right hand corner of the window Erosion will not be included in the analysis unless the Calculate Erosion option is activated on the Erosion tab see next section 2 3 Estimating Sediment Loads optional Use the Erosion tab to indicate whether you want OpenNSPECT to calculate erosion The content of the erosion tab will change according to whether an even
6. factor that quantifies the susceptibility of soil particles to detachment and movement by water The K factor is used in RUSLE and MUSLE to calculate soil loss by water The two most important factors related to soil erodibility are infiltration capacity and structural stability Low infiltration capacity would cause more surface runoff and the surface is less likely to be ponded making soil more susceptible to splashing Some properties that create a high K factor value are high contents of silt and clay or impervious soil layers Areas without a K factor value disturbed soils will be assumed to carry a K value of 0 30 Advanced MUSLE Specific Parameters MUSLE requires two constants that can be locally calibrated to estimate event based erosion In the Advanced MUSLE Specific Parameters section the universal MUSLE equation is given under MUSLE Equation for sediment yield The user can enter locally specific constants into the text boxes under MUSLE Equation for Sediment Yield Delete Soils Configuration To delete an existing soils data set select the desired soils data set for deletion in the Name field and select Delete from the Options menu Confirm the choice to delete when prompted and the selected soils data set will be deleted from the database 31 4 Output OpenNSPECT produces three primary types of pollution and erosion output estimates These are local effects accumulated effects and pollutant concentration The
7. loss from bare soil The cover factor reduces the soil loss estimate according to the effectiveness of vegetation at preventing detachment and transport of soil particles The higher the value the more erosion that occurs for example bare land has a relatively high cover factor Specify whether the land cover type is water or wetland in the Wet column If the land cover class is water or wetland the box in this column should be checked For any non water class the box should be left unchecked This distinction is necessary for an accurate calculation of erosion Delete Land Cover Type To delete an existing land cover type select the land cover type to be deleted from the Land Cover Type drop down list and choose Delete from the Options menu The selected land cover type and all associated coefficient sets will be deleted from OpenNSPECT s database and will no longer appear in the Land Cover Type drop down list Note The C CAP land cover type cannot be deleted 15 Import Land Cover Type 5 Import Land Cover Type x Land Cover Type Name Import File A OK Cancel The import function will allow you to use land cover data sets from other OpenNSPECT users without entering them by hand Other users can use the export function to save the land cover curve numbers and cover factor in the appropriate format To import a land cover type select Import from the Options menu Name the file and navigate to the folder in
8. which it is located The imported file must be an ASCII file containing a header row followed by a row of comma separated values for each land cover class The header row should contain the name of the land cover type and a description separated by a comma no space Each row must contain seven fields ordered as follows Value name Curve A Curve B Curve C Curve D CoverFactor Wet Supply a name for the new land cover type when it is imported The new land cover type will be added to the Land Cover Type drop down list 6 import_landcover Notepad t Oj x File Edit Format view Help CCAP C CAP Landcover coefficients 0 Background 0 0 0 0 0 0 1 No Data 0 0 0 0 0 0 oa Intensity Developed 0 89 0 92 0 94 0 95 0 0 jum Intensity Developed 0 77 0 85 0 9 0 92 0 01 0 4 Low Intensity Developed 0 61 0 75 0 83 0 87 0 03 0 5 Developed Open Space 0 49 0 69 0 79 0 84 0 005 0 6 Cultivated Land 0 67 0 78 0 85 0 89 0 24 0 7 Pasture Hay 0 39 0 61 0 74 0 8 0 05 0 8 Grassland 0 3 0 58 0 71 0 78 0 12 0 9 Deciduous Forest 0 3 0 55 0 7 0 77 0 009 0 10 Evergreen Forest 0 3 0 55 0 7 0 77 0 004 0 ha Export Land Cover Type The export function will allow you to share land cover data sets with other OpenNSPECT users who can use the import function to load the land cover curve numbers and cover factor without entering the values by hand To export a land cover type select the land cover type to be exported from the Land Cover Type drop down list
9. User s Manual for OpenNSPECT Version 1 1 Jory 23072 NATIONAL OcEANIC AND ATMOSPHERIC ADMINISTRATION NOAA COASTAL SERVICES CENTER An Open Source Version of the Nonpoint Source Pollution and Erosion Comparison Tool MOsp NOAD S Phe a a NATIONAL S Sce PS D ATMENT oF O NOAA Coastal Services Center LINKING PEOPLE INFORMATION AND TECHNOLOGY 2234 South Hobson Avenue Charleston South Carolina 29405 2413 843 740 1200 www csc noaa gov Regional Offices NOAA Pacific Services Center NOAA Gulf Coast Services Center and Offices in the Great Lakes Mid Atlantic Northeast and West Coast Table of Contents o o A A ONO 1 1 Getting Starte ii A A dada 2 1 1 Installing MapWindow GIS ccccccnnnonoooonnnnnnnnnnonononnnnnnnnnconnnnnnn ono nnnnnnnnonnnnnnnnnnnnnnnnnnns 2 1 2 Installing OpenNSPECT id 2 1 3 Loading OpenNSPECT mirre dieat a a a a a 2 2 RUNING am Analysis eissa E 3 2 1 Setting Upa Project ipni ennn a a a ekaa aaa eri iaa Tea Taia 3 2 2 Estimating Pollutant Load Sereni eanne aaa a Ee E a r 5 2 3 Estimating Sediment Loads optional ad A dido 6 2 4 Incorporating SCenarlOS occcccccconooonncnnnnnnnnnnnnnnnonannccnnnnnonaonnnncnnnnnnonananonacnannnnonananinass 7 PAL EAMG A A RN 7 2 4 2 Management ScenariOS ccccccccnononcnncnncnnnnnnnnnnononncnnnnnnonnnnncnnnnnnnncnnnnnnonnnncnnnnnnnnnss 9 3 Advanced Setting Sii a E E 12 NA AE EE A died seus caus A O AA 12 32 POMAR dd 17 Bed C effici
10. and a new coefficient set will be created with the values defaulting to zero Enter a description of the coefficient set Enter a coefficient for each land cover class defined for the land cover type Values must be entered for at least one of the four types Types 1 through 4 5 Add Coefficient Set xj Coefficient Set Name new_set_name Land Cover Type CCAP v Cancel Copy Coefficient Set To copy a coefficient set select Copy Set from the Coefficient menu Designate a coefficient set to copy from and a new coefficient set name The Copy from Coefficient Set drop down menu will contain all defined coefficient sets for the selected pollutant Click OK and a new coefficient set will be created that is identical to the coefficient set selected in the Copy from Coefficient Set field The coefficient values may be edited for the new set 19 xi Copy from Coefficient Set Lead Set y New Coefficient Set Name new_lead_set Cancel Delete Coefficient Set To delete an existing coefficient set select the desired coefficient set for deletion and select Delete Set from the Coefficient menu Confirm the choice to delete when prompted The selected coefficient set will be deleted from the database Import Coefficient Set xi New Coefficient Set Name import_coeff_set Land Cover Type CCAP De Import File Ct al Cancel To import a coefficient set select Import Set from the Coefficients menu Specify a name for the coeffici
11. be acquired from the 6 NRCS SSURGO data set To use a grid check Use GRID and select the appropriate grid from the drop down list of grids loaded in the MapWindow project To use a constant value check Use Constant Value and enter a valid numeric value greater than zero This constant rainfall factor value will be applied for the entire study area e Sediment Delivery Ratio GRID The Sediment Delivery Ratio SDR GRID is a raster data set that is used to calculate the amount of sediment delivered from a cell The Universal Soil Loss Equation calculates the amount of sediment that is mobilized from an area and the SDR is used to adjust the amount of sediment that actually leaves a cell OpenNSPECT automatically calculates the SDR grid using the digital elevation model associated with the specified watershed delineation when an annual erosion analysis is run but users are also encouraged to specify their own SDR grid here if one is available 2 4 Incorporating Scenarios 2 4 1 Land Uses Use the Land Uses tab to define a specific land use and new Soil Conservation Service SCS curve number and pollutant coefficient set for a particular area OpenNSPECT will use this new land use scenario to calculate runoff pollutant and sediment loads in this area The original land cover grid values will be ignored in the calculation For example if a known area is a landfill a new land use type landfill can be defined with appropriate coefficients t
12. ch land cover class in the new land cover type To add insert or delete a row right click in the table SCS Curve Numbers Specify the SCS curve numbers in the CN A CN B CN C and CN D columns Curve numbers represent the infiltration of precipitation into the soil The four columns represent the curve numbers for each of the four hydrologic soil types which indicate the soil s minimum infiltration rate The water that infiltrates is not included in the flow accumulation calculations therefore a more accurate prediction of the total runoff is provided SCS curve numbers are percentages entered into OpenNSPECT in decimal form as numbers between 0 and 1 the higher the curve number the greater the amount of runoff Group A soils typically sand or gravel have the highest infiltration potential and Group D soils typically clay soils have the lowest infiltration potential Group B soils typically silt with fine to moderately course textures have a moderate infiltration rate and Group C soils typically sandy clay with a moderately fine to fine texture have a low infiltration rate For instances where a dual hydrologic group is assigned for example A D B D C D the highest curve number of the two components is used RUSLE Specify the cover factor for each land cover type The cover factor is typically a number between 0 and 1 and is essentially the ratio of soil loss from land under specified vegetative conditions to the corresponding
13. ch time you make changes or the original project parameters will be lost e Working Directory Designate a working directory for your project The working directory will default to C NSPECT workspace C Land Cover e Grid Select the land cover grid that will be used in the analysis The field contains a drop down list of all grids loaded in the MapWindow project e Type Select the land cover type that matches the selected land cover grid The drop down list contains all currently defined land cover types see Advanced Settings gt Land Cover to learn how to add a land cover type D Watershed Delineation Select the watershed delineation data to be used in the analysis from the drop down list of all currently defined watershed delineations or define a new watershed delineation see Advanced Settings gt Watershed Delineations to learn how to add a watershed delineation These water quality standards can be acquired from state and local water quality regulatory agencies E Precipitation Scenario Select the precipitation scenario to be used in the analysis from the drop down list of all currently defined precipitation scenarios or define a new precipitation scenario see Advanced Settings gt Precipitation Scenarios to learn how to add a precipitation scenario F Soils e Hydrologic Soils Data Set Select the soils configuration that will be used in the analysis The drop down list contains all currently defined soil confi
14. ct the land cover type to be viewed or edited All currently defined land cover types are available via the Land Cover Type drop down list When a land cover type is selected the remaining fields are automatically populated with information about the selected land cover type Use the Options menu to create import delete or export a land cover type Land Cover Types No x Options Edit Help Description a CNA CNB CNC CND Cover Factor Background ooo 0 0000 aooo omo 0 000 No Data 0 0000 o 0000 o0000 0 0000 0 000 High Intensity Developed 0 8900 0 3200 0 3400 0 9500 0 00 Medium Intensity Developed 10 7700 0 8500 0 3000 0 9200 0 010 Low Intensity Developed 0 6100 0 7500 0 8300 08700 0 030 Developed Open Space 0 4900 0 6900 0 7900 0 8400 0 005 Cultivated Land 0 6700 0 7800 0 8500 0 8900 0 240 Pasture Hay 0 3900 0 6100 0 7400 0 8000 0 050 Grassland 0 3000 0 5800 0 7100 0 7800 0 120 Deciduous Forest 0 3000 05500 07000 o7700 0 009 Evergreen Forest 0 3000 0 5500 0 7000 0 7700 0 004 Mixed Forest 0 3000 0 5500 0 7000 0 7700 0 007 Restore Defauts Cancel 12 Land Cover Use this to designate the land cover type The drop down list contains all currently defined land cover types within OpenNSPECT Description A brief description of the selected land cover type P
15. d according to the selected pollutant Use the Coefficients tab to view or edit information about the defined coefficient sets for the selected pollutant Pollutants x Pollutants Coefficients Help hc E Coefficients water Quality Standards Coefficient Set Lead Set y Land Cover Type CCAP Description Default lead coefficients CCAP 2001 classification scheme Class Coefficients mg L Name Type 2 Type 3 Type 4 Background 0 0000 0 0000 0 0000 No Data i 0 0000 0 0000 o 0000 High Intensity Developed i 0 0000 0 0000 PPP R i Y E PESE E 17 Add Pollutant To add a new pollutant select Add from the Pollutants menu 2 Add Pollutant x Coefficients Pollutant Name Coefficients Coefficient Land Cover Type CCAP y Description Class Coefficients mg L Name Background No Data High Intensity Developed Medium Intensity Developed Low Intensity Developed Pollutant Name Provide a name for the new pollutant being added limit of 35 characters Coefficient Set Provide a name for the coefficient set to associate with the new pollutant Land Cover Type Select the type of land cover that will be used to define new coefficients for the pollutant being added Description Provide a brief description less than 100 characters of the new coefficient set Class The Value and Name columns conta
16. d use changes caused a decrease in the variable measured Note that this interpretation depends on entering the changed scenario in the left pane and the original scenario in the right pane e Percent Change 100 Management Baseline Baseline produces a grid of the relative difference between the modified scenario and the original scenario expressed as a percentage change from the original values Zero equals no change positive numbers indicate the land use changes caused an increase and negative numbers indicate the land use changes caused a decrease in the variable measured Note that this interpretation depends on entering the changed scenario in the left pane and the original scenario in the right pane Compare Outputs Select Compare Outputs from the OpenNSPECT toolbar All OpenNSPECT output group layers will be displayed in the left and right selection boxes Choose a modified that is a management or land use scenario run in the left box and a baseline scenario for the same area in the right box Compare OpenNSPECT Outputs 0 x File Compare Modified to Orignal Output Select Modified Output Select Original Output ccap05 baseline Position 0 ccap05 management scenario Position 1 ccap05_management_scenario Position 1 M Show Only Output Group from Legend Y Show Only Output Group from Legend Limit Output Selection to Those in the MapWindow Legend To view only the layers currently open in MapWindow cl
17. delete an existing watershed delineation select the desired watershed delineation for deletion in the Delineation Name field and select Delete from the Options menu Confirm the choice to delete when prompted and the selected watershed delineation will be deleted from the database 3 6 Soils Soils data are used to estimate sediment loads using the NRCS developed RUSLE and MUSLE equations RUSLE is used to estimate average erosion over time whereas MUSLE is used to estimate erosion from specific rainfall events OpenNSPECT was developed using soils data from the SSURGO database however any land soils data can be used in the tool provided the data are in the appropriate format The soils configurations that are defined within OpenNSPECT are listed in the Name drop down list in the Soils window Fields in the Soils window are populated according to the selected soil name OpenNSPECT provides the ability to create a new soils configuration or delete a soils configuration xi Options Help M Soils Configuration Name HI_SampleS oils y Soils C NSPE CT HI_Sample_Data soils1 tif Soils K Grid C NSPECTSHI_Sample_Data soilsk1 tif Add New Soils Configuration To define a new soils data set select Advanced Settings and then Soils and select New from the Options menu 29 x Name DEM GRID 5 m Soils Soils Dast ol Hydrologic Soil Group Attribute y K Factor Attribute v Advanced MUSLE Specific Coeffic
18. down list of all polygon layers defined in the active data frame Then select the new land cover class for the region e Delete Row Delete an existing management scenario by clicking on the appropriate row and selecting Delete Row from the pop up menu that displays by right clicking within the table Confirm the choice to delete when prompted and the selected management scenario and its associated information will be deleted from the database 11 3 Advanced Settings The Advanced Settings menu provides access to functionality for viewing editing and adding region specific data sets and parameters Default data sets and parameters are defined for the Wai anae region and have been provided with OpenNSPECT Users in the Wai anae area who choose to use the default data can skip the Advanced Settings section and go directly to the Run Analysis menu selection Users who want to use OpenNSPECT in other regions nationwide can use the advanced settings to incorporate data from their local area 3 1 Land Cover Land cover data are the basis of OpenNSPECT s functionality Land cover is used to estimate pollutant loads by applying coefficients for individual pollutants to each land cover class OpenNSPECT was designed using NOAA s Coastal Change Analysis Program C CAP land cover data however any land cover data can be used in the tool provided the appropriate pollutant coefficients have been defined Use the Land Cover Types window to sele
19. ed by the NRCS The National Weather Service s duration frequency data or local storm data were used to develop these distributions All of Hawaii is Type rainfall Delete Precipitation Scenario To delete an existing precipitation scenario select the desired precipitation scenario for deletion in the Scenario Name field and select Delete from the Options menu Confirm the choice to delete when prompted and the selected precipitation scenario will be deleted from the database 3 5 Watershed Delineations Watersheds are a common and logical analysis unit for conducting water quality assessments The first step in creating a vector layer of watershed polygons is to load a digital elevation model DEM OpenNSPECT generates a flow direction grid flow accumulation grid vector watersheds layer and length slope LS factor grid when a new watershed delineation is created The watershed delineations that are already defined within OpenNSPECT are listed in the Watershed Delineation Name drop down list in the Watershed Delineations window Fields in the Watershed Delineations window are populated according to the selected watershed delineation name OpenNSPECT provides the ability to create a new watershed delineation delete an existing watershed delineation and enter the unique components of a watershed delineation 24 lt 4 Watershed Delineations xj Options Help Browse Watershed Delineations Watershed Delineation Name IEPS
20. ed the DEM by filling sinks If this check box is cleared OpenNSPECT will automatically perform this hydrological correction process before creating the watershed delineation Subwatershed Size Subwatershed size designates the subwatershed size small medium or large for the selected watershed delineation The subwatershed size is relative to the DEM a small subwatershed is 3 percent of the maximum flow accumulation value a medium 25 subwatershed is 6 percent of the maximum flow accumulation value and a large subwatershed is 10 percent of the maximum flow accumulation value This field cannot be edited in this window Watershed This field displays the watershed file that was created in the watershed delineation process Flow Accumulation Grid This field displays the accumulation grid that was created when the selected watershed delineation was created Each cell in the flow accumulation grid contains the total value of all cells upstream of that cell LS Grid The LS Grid is the length slope grid that is used in calculating erosion Length slope is a parameter needed to use the MUSLE equation to estimate soil loss from a short term rain event Add New Watershed Delineation A new watershed delineation can be created in one of two ways 1 New o Automatic delineation from user specified DEM o Inthe Run Analysis project window use the Watershed Delineation drop down menu to select New watershed delineation All the defined wate
21. ent set to be imported and the land cover type that will be associated with it Browse for the coefficient set file that contains the values to be imported The file must contain a header row with the name of the land cover type and a description separated by a comma no space The imported file must be an ASCII file containing a row of comma separated values for each land cover class Each row must contain five fields ordered as follows Value Type 1 Type 2 Type 3 Type 4 The new coefficient set will be added to the Coefficient Set drop down list The associated land cover type should match the land cover values defined within the import file The new coefficient set will be added to the Coefficient Set drop down list AE File Edit Format View Help p 0 0 0 0 1 0 0 0 0 212 22 0 0 0 3 2 29 0 0 0 4 1 77 0 0 0 5 1 25 0 0 0 6 2 68 0 0 0 2 48 0 0 0 8 1 25 0 0 0 9 1 25 0 0 0 10 1 25 0 0 0 dt L 23 0 0 0 y 20 Export Set To export a coefficient set select Export Set from the Coefficients menu Name the file and designate a location to save it The coefficient set will be written to a comma separated ASCII file containing a row of values for each land cover class Each row will contain five fields ordered as follows Value Type 1 Type 2 Type 3 Type 4 3 4 Precipitation Scenarios The intensity length of precipitation event and amount of precipitation that falls during an event has a large impact on the amount of
22. entS A A AA AS 19 3 4 Precipitation SCENAllOS vesiceccc sciveleesivescsshesendsessnoncssdileadsauaeelecshcdendacessesedsaduudsevbeeseusle 21 30 Watershed Delle OS iii A a A R iai 24 A O 29 A QUCPU eis isicasivsccccisecnssesivncscaadecesssedeesscccued sasesoss culesatecsousndedsddsseuscansoduecseuedesesoussvecdens 32 4 1 Comparing Dutputs ias is 32 MAA A E S 35 Gs Hints ANACO YSL A e 36 Introduction OpenNSPECT is the open source version of the Nonpoint Source Pollution and Erosion Comparison Tool that examines the relationship between land cover nonpoint source pollution and erosion OpenNSPECT is a plug in for the free open source geographic information system GIS software package MapWindow GIS OpenNSPECT is designed for use with any watershed provided the user has access to the necessary data This user s manual provides a detailed description of the interfaces within OpenNSPECT and the data required to perform an analysis The separate technical guide explains in more detail where the data that are distributed with OpenNSPECT were acquired and how the data were processed to be compatible with OpenNSPECT OpenNSPECT uses spatial elevation data to calculate flow direction and flow accumulation throughout a watershed To do this land cover soils and precipitation data sets are processed to estimate runoff volume at both the local and watershed levels Coefficients representing the contribution of each land cover class to the expected po
23. erosion that occurs during the rainfall Erosion is calculated differently using annual precipitation data than it is using event specific data The RUSLE is used to calculate average annual erosion with annual precipitation data while the modified universal soil loss equation MUSLE is used to calculate erosion from specific events and requires event specific rainfall data A precipitation scenario must be specified to calculate runoff within OpenNSPECT The precipitation scenarios that are defined within OpenNSPECT can be modified or new scenarios can be created OpenNSPECT also provides the ability to delete precipitation scenarios Precipitation Scenarios l x Options Help Choose a precipitation scenario to view or edit Scenario Name AnnualPrecipitation y Description Annual Precipitation for Waianae Precipitation Grid CANSPECTAHI_Sample_DataWHI_annual_prec tif El Grid Units meters sisi Precipitation Units finches A Time Period nnu o Raining 7 Type lypel ti el 21 Modify Precipitation Scenario To modify an existing precipitation scenario select Advanced Settings gt Precipitation Scenarios Fields in the Precipitation Scenarios window are populated according to the selected scenario Scenario Name This field contains a drop down list of all the currently defined precipitation scenarios Fields in the Precipitation Scenarios window are populated according to the selected scenario name Th
24. gurations The soils configuration specifies the grid that contains spatial values for the hydrologic soil types A B C or D depending on the soil s infiltration rates in the area of interest and the grid that contains spatial values for the K factor soil erodibility factor in the area of interest see Advanced Settings gt Soils to learn how to add a soil configuration G Miscellaneous e Selected Polygons Only Select this check box to perform the analysis on a selected area The analysis will be performed in the entire watershed or catchment basin in which the polygon is located but the output will be clipped to the selected area This option is only active if a polygon data layer is loaded in the MapWindow project e Include Local Effects Select this check box to remove the influence of upstream cells from the analysis Local Effects will only account for the runoff pollutants and sediment yield generated at each cell rather than incorporating the cumulative effects of upstream cells in the watershed 2 2 Estimating Pollutant Loads Use the Pollutants tab to define which pollutants to include and which coefficient set to apply in the analysis All the pollutants in the database with defined coefficient sets are listed in the table Pollutants Erosion Land Uses Management Scenarios Nitrogen Total Suspended Solids Zinc Apply To include a pollutant in the analysis select the check
25. hat are applied only to that area Note When both a land use scenario and a management scenario see next section are selected for the same area the management scenario will be performed first The final result in the overlapping area will reflect the land use scenario that was specified Pollutants Erosion Land Uses Management Scenarios Apply Land Use Scenario Edit Scenario Delete Scenario Note Right click the table to Add Edit and Delete Land Use Scenarios Run Cancel e Apply To include a land use scenario in the analysis select the check box in the Apply column To exclude the land use scenario from the analysis clear the check box The column defaults to cleared which means that the land use scenario in that row will not be included in the analysis e Land Use Scenario The Land Use Scenario column on the Land Uses tab displays all the land use scenarios that have been defined for the current project Add edit or delete a scenario by right clicking within the table Add Land Use Scenario A new scenario can be added to OpenNSPECT by right clicking in the table on the Land Uses tab and selecting Add Scenario from the drop down list s Add Land Use Scenario xj Scenario Name new_land_use Es EE I Use Selected Polygons Only Select O selected SCS Curve A B E D 0 0 0 0 Cover Factor fo T Water Wetlands Coefficients Pollutant Type 1 Type 2 Type 3 Type 4 Ph
26. ick the Show Only Output Group from Legend check box 34 5 Metadata Each data set that is delivered with OpenNSPECT has a metadata file associated with it that can be accessed with the MapWindow View Metadata tool The same is true for each output data set that is created with OpenNSPECT Each time a new analysis is completed metadata are created for each output data set which includes information such as the OpenNSPECT project the output file is associated with and the parameters that were chosen to run the tool when the data set was created 35 6 Hints and Acronyms Right clicking within the tables contained in the OpenNSPECT window will allow you to append a row add a blank row at the end of the grid insert a row insert a blank row above the current row or delete a row from the table ASCII American Standard Code for Information Interchange C CAP Coastal Change Analysis Program DEM digital elevation model LS length slope MUSLE modified universal soil loss equation NOAA National Oceanic and Atmospheric Administration NRCS Natural Resources Conservation Service NWS National Weather Service RUSLE revised universal soil loss equation SCS Curve Number Soil Conservation Service Curve Number SDR sediment delivery ratio SSURGO Database Soil Survey Geographic Database USDA United States Department of Agriculture USGS United States Geological Survey 36
27. ients MUSLE Equation for sediment yield a 0 a K C P LS 95 b 056 Locally calibrated MUSLE coefficients can be entered above Warning OQ and qp are calculated in English units acre feet and cubic feet per second respectively a and b must be derived accordingly CE ces Name Provide a name for the new soils configuration being added limit of 35 characters DEM GRID Browse to specify the DEM Grid that you are using in the analysis area This should match the DEM grid used in the watershed delineation process Soils Data Set Select the soils data set polygon shapefile layer that contains soils information for the area of interest The soils data currently provided in OpenNSPECT were acquired from the U S Department of Agriculture USDA NRCS SSURGO database Although these data are available for download on the Web a few modifications are necessary before they can be loaded into OpenNSPECT See the OpenNSPECT technical guide for information on processing the soils data Hydrologic Soil Group Attribute Select the attribute in the soils data set that corresponds to the hydrologic soil group information The hydrologic group hydgrp is an attribute found in the component table of the SSURGO database The hydrologic group is assigned based on soil infiltration rates These are grouped into four categories A through D based on decreasing infiltration A high infiltration D very slow infiltration 30
28. in the grid value and corresponding name for each land cover class defined for the associated land cover type These values cannot be edited Coefficients Enter coefficients into the table for each land cover class Only one type of coefficient is required so only one column must be completed but the functionality to enter four different types of coefficients is available The coefficients give the average concentration of the selected pollutant that is released by the identified land cover during a precipitation event This is frequently referred to as the Event Mean Concentration 18 Delete Pollutant To delete an existing pollutant select the desired pollutant for deletion and select Delete from the Pollutants menu Confirm the choice to delete when prompted The pollutant all associated coefficient sets and all references to the pollutant in water quality criteria will be deleted from the database 3 3 Coefficients Coefficients give the average concentration of the selected pollutant that is released by the identified land cover during a precipitation event This is frequently referred to as the Event Mean Concentration Add New Coefficient Set To create a new coefficient set select the pollutant for which you want to create a new coefficient set in the Pollutant drop down field and select New Set from the Coefficients menu Designate a Coefficient Set Name and associate a land cover type in the Land Cover Type field Click OK
29. ion software MapWindowx86Full v48Final installer exe from the Digital Coast www csc noaa gov digitalcoast tools nspect download 2 Run MapWindowx86Full v48Final installer exe Follow the prompts to install the software A MapWindow GIS icon will be added to your desktop The software will reside at C Program Files x86 MapWindow 1 2 Installing OpenNSPECT OpenNSPECT is a plug in extension for MapWindow GIS Installation requires administrative privileges on the target computer 1 Download the OpenNSPECT installation software OpenNSPECT v1_1_installer exe from the Digital Coast www csc noaa gov digitalcoast tools nspect download 2 Be sure that the MapWindow program is not running and then run OpenNSPECT v1_1_installer exe Follow the prompts to install the software An NSPECT directory will be installed on your C drive Note If a previous version of OpenNSPECT is already installed it should be removed before installing a new version To uninstall the previous version use the function Add Remove Programs in the Control Panel select OpenNSPECT and click Change Remove Then follow the instructions from the wizard to uninstall the tool Check the location where OpenNSPECT was installed and make sure it is empty the directory will not be deleted which is fine 1 3 Loading OpenNSPECT e Open MapWindow GIS A Welcome to MapWindow dialog box will appear Select Close to dismiss the box e From the MapWindow pu
30. is field cannot be edited Description This box provides a brief description of the selected precipitation scenario The description for the precipitation scenario can be modified and saved Precipitation Grid The precipitation grid contains spatial values for precipitation over the area of interest The name and path of the precipitation grid are displayed To change the precipitation grid associated with the scenario use the browse button to select a precipitation grid for your analysis and choose Add Grid Units This field defines cell size units meters or feet of the specified precipitation grid Precipitation Units This box defines the precipitation units centimeters or inches used in the precipitation grid Time Period This field specifies the type of precipitation scenario annual or event depending on the precipitation data set that is being used Annual precipitation events will use different methods for estimating soil erosion than event based precipitation events The annual and event types of precipitation scenarios for Wai anae were developed in conjunc tion with the Hawaii state climatologist See the OpenNSPECT technical guide for specific details Raining Days This number indicates the average number of storms that occur in a one year period in the area of interest This parameter is very sensitive and typically requires careful consideration While it isn t recommended that users simply adjust this value to ca
31. librate OpenNSPECT to local conditions users are encouraged to employ creative methods to accurately reflect spatial variation in raining days Type This field specifies the rainfall type in the analysis region The different rainfall types describe the four synthetic 24 hour rainfall distributions developed by the NRCS The National Weather Service s duration frequency data or local storm data were used to develop these distributions All of Hawaii is Type rainfall see following table for descriptions of rainfall types 22 NRCS Rainfall Distributions Type Description Types I and IA Pacific maritime climates with wet winters and dry summers Type IA is the least intense rainfall Type Il Most of the country falls into this category Type Il is the most intense short duration rainfall Type Ill Atlantic coastal areas and the Gulf of Mexico where tropical storms with large 24 hour rainstorms occur New Precipitation Scenario Anew precipitation scenario can be created in one of two ways e Inthe Run Analysis project window use the Precipitation Scenario drop down menu to select New precipitation scenario All the defined precipitation scenarios will be listed in this drop down menu but the last entry in the list will give the option to create a new precipitation scenario e Select Precipitation Scenarios under Advanced Settings and select New from the Options menu Either one of these options will take you to the
32. ll down menu select Plug ins gt OpenNSPECT This will add OpenNSPECT to the main pull down menu 2 Running an Analysis 2 1 Setting Up a Project Use the Run Analysis option on the main OpenNSPECT menu to define all parameters required to perform an analysis within a defined region Use the File menu to create a new project or open an existing project file Use the Pollutants tab to define which pollutants to include in the assessment Use the Erosion Land Uses and Management Scenarios tabs to specify optional parameters to consider in the analysis 2 OpenNSPECT Example Project Watershed Delineation Waianae YD Hydrologic Soils Data Set Waianae F m A File Use the File menu to create a new project to open a previously defined project or to save a new or modified project Select New Project to start a new analysis Select Open Project to open an existing project file Fields in the project setup window will be automatically filled with the information that was previously saved Choose Save or Save As to save the current project B Project Information e Name To save the parameters in a project file designate a name for the project when a new project is created or an existing project is modified The parameters that are used in each analysis are saved in this project file which is in xml format Be sure to save the project under a new name ea
33. llutant load are also applied to land cover data sets to approximate total pollutant loads These coefficients were derived from a combination of relevant studies and local water quality sampling data or taken from published sources The output layers display estimations of runoff pollutant loads pollutant concentration and total sediment loads These layers can help resource managers make informed decisions about water quality and what areas to target for improvement as well as predict the impacts of management decisions on water quality OpenNSPECT also provides functionality to compare current land cover conditions to proposed changes in both land use and land cover Note Data provided with OpenNSPECT are for the Wai anae area located on the western side of O ahu Hawaii The technical guide explains in more detail where the data were acquired for the Wai anae study area and how the data were processed to be compatible with OpenNSPECT 1 Getting Started 1 1 Installing MapWindow GIS The MapWindow desktop software is available through free download as a single ready to install exe file from the MapWindow website www mapwindow org Installation requires administrative privileges on the target computer MapWindow is a native Windows application that requires installation of the Microsoft NET framework It runs on XP Vista and Windows 7 A Quick Start Guide is available on the MapWindow website 1 Download the MapWindow GIS installat
34. local effects outputs are estimates of the amount in units of mass of pollutants or sediments that are originating from that particular location The accumulated effects outputs are estimates of the total pollutant or sediment load delivered to through a location again in units of mass The concentration outputs are estimates of the average concentration at a location given what is flowing in from upstream These are in units of concentration mass volume If there is nothing coming from upstream these would be the same as the pollutant coefficients Note that there are no concentration results from the RUSLE MUSLE calculations Output data sets are organized and displayed in the MapWindow Legend using group layers Data sets that result from running an OpenNSPECT analysis for accumulated effects will include e Accumulated runoff volume grid liters This grid displays accumulated values of water volume at each cell in the analysis area These values are used in calculating the pollutant and sediment concentration grids by dividing the pollutant sediment accumulation grid by the water volume to give a concentration e Accumulated pollutant grid kilograms This grid displays the accumulated load of the specified pollutant at each cell in the analysis area e Pollutant concentration grid milligram per liter Each cell in this grid gives an estimate of the concentration of the specific pollutant at that location The user can easily identify
35. nd cover within a specified region to a different land cover class that is already defined in the land cover classification being used in the analysis For example to estimate the impact of a new housing development you can create a polygon shapefile of the area that will be developed and apply the high medium or low intensity developed land cover class to that specific area The coefficients for the newly designated land cover class will be used in these designated areas rather than the coefficients for the original land cover data set Note The original land cover data set will not be changed but original coefficients will be ignored When both a land use scenario and a management scenario are selected for the same area the management scenario will be performed first The final result in the overlapping area will reflect the land use scenario that was specified E Pollutants Erosion Land Uses Management Scenarios Apply Change Area Layer gt w Waianae Drainage Basins Note Right click the table to Append Insert and Delete Rows Run Cancel e Apply To include a management scenario in the analysis select the check box in the Apply column To exclude the management scenario from the analysis clear the check box The column defaults to cleared which means that the management scenario in that row will not be included in the analysis e Change Area Layer Select the polygon layer that will be changed
36. osphorus Nitrogen Total Suspended Solids 0 Zinc 10 Lead Cancel e Scenario Name Provide a name for the new scenario being added limit of 35 characters e Layer Select the polygon layer that delineates the area of your land use The drop down list contains all defined polygon layers in the MapWindow project The new land use type will be applied to the entire selected layer Note When both a land use scenario and a management scenario are selected for the same area the management scenario will be performed first e SCS Curve Numbers Designate SCS curve numbers for the new land use type for each soil type A B C and D The SCS curve numbers represent the infiltration of precipitation into the soil and are used when calculating runoff and erosion The water that infiltrates is not included in the flow accumulation calculations therefore a more accurate prediction of the total runoff is provided SCS curve numbers are percentages entered into OpenNSPECT in decimal form as numbers between 0 and 1 the higher the curve number the greater the amount of runoff The four columns A B C and D represent the curve numbers for each of the four hydrologic soil types which indicate the soil s minimum infiltration rate Group A soils typically sand or gravel have the highest infiltration potential and Group D soils typically clay soils have the lowest infiltration potential Group B soils typically silt wi
37. r large for the selected watershed delineation The subwatershed size is relative to the DEM a small subwatershed is 3 percent of the maximum flow accumulation value a medium subwatershed is 6 percent of the maximum flow accumulation value and a large subwatershed is 10 percent of the maximum flow accumulation value Note This field cannot be edited in this window Click OK to derive the new watershed delineation and process all associated files 27 New from existing data Users can create a new watershed delineation using derivatives created outside of OpenNSPECT Y Define From Existing Watershed Delineation xi Define Watershed Delineation Watershed Delineation Nam DEM 6 o l DEM Unt ts Flow Direction Grid FlowAccumiaion Gt LengthslopeGid O Watersheds SSS gh ox tano Watershed Delineation Name Provide a name for the new watershed delineation being added limit of 35 characters DEM Grid Browse to the DEM Grid that will be used for the analysis in the area of interest This grid should be hydrologically corrected DEM Units Specify the DEM grid vertical units meters or feet for the selected DEM Flow Direction Grid Select the flow direction grid Flow Accumulation Grid Select the flow accumulation grid Length Slope Grid Select the length slope grid Watersheds Select the shapefile polygon that represents unique watersheds 28 Delete a Watershed Delineation To
38. rovide a description less than 100 characters when importing or creating a new land cover type data set Classification This column contains the grid value and corresponding name for each land cover class in the currently selected land cover type Provide values and names when creating a new land cover data set SCS Curve Numbers The SCS curve numbers represent the infiltration of precipitation into the soil The water that infiltrates is not included in the flow accumulation calculations therefore a more accurate prediction of the total runoff is provided SCS curve numbers are percentages entered into OpenNSPECT in decimal form as numbers between 0 and 1 the higher the curve number the greater the amount of runoff The four columns CN A CN B CN C and CN D represent the curve numbers for each of the four hydrologic soil types which indicate the soil s minimum infiltration rate Group A soils typically sand or gravel have the highest infiltration potential and Group D soils typically clay soils have the lowest infiltration potential Group B soils typically silt with fine to moderately course textures have a moderate infiltration rate and Group C soils typically sandy clay with a moderately fine to fine texture have a low infiltration rate For instances where a dual hydrologic group is assigned for example A D B D C D the highest curve number of the two components is used see the OpenNSPECT Technical Guide for a detailed de
39. rshed delineations will be listed in this drop down menu but the last entry in the list will give the option to create a new watershed delineation o Select Watershed Delineations under Advanced Settings and select New from the Options menu Either one of these options will take you to the New Watershed Delineation dialog box 2 New from existing data o Manual input of watershed delineation files This option is designed for the power user who wants to have maximum control over the DEM derived data layers 26 New delineation from user specified DEM Create New Watershed Delineation E x Create a new watershed delineation Delineation Name DEM Grid CA El T DEM is hydrologically correct filled DEM Units o yl Subwatershed Size I ok Cancel Delineation Name Provide a name for the new watershed delineation being added limit of 35 characters DEM Grid Browse to the DEM Grid that will be used for the analysis in the area of interest DEM Units Specify the DEM grid units meters or feet for the selected DEM DEM is hydrologically correct filled Check the DEM is hydrologically corrected box if the DEM has already been hydrologically corrected by filling sinks If this check box is cleared OpenNSPECT will automatically perform this hydrological correction process before running the analysis Subwatershed Size Select the subwatershed size to indicate the approximate subwatershed size small medium o
40. scription Default values for C CAP land cover data are provided with OpenNSPECT Provide SCS curve number values when creating a new land cover data set Hydrologic Soil Group Definitions Hydrologic Soil Group Soil Group Characteristics Soils having high infiltration rates even when thoroughly wetted and A consisting chiefly of deep well drained to excessively drained sands or gravels These soils have a high rate of water transmission Soils having moderate infiltration rates when thoroughly wetted and consisting chiefly of moderately deep to deep and moderately fine to B moderately coarse textures These soils have a moderate rate of water transmission Soils having slow infiltration rates when thoroughly wetted and consisting c chiefly of soils with a layer that impedes downward movement of water or soils with moderately fine to fine texture These soils have a slow rate of water transmission Soils having very slow infiltration rates when thoroughly wetted and consisting chiefly of clay soils with a high swelling potential soils with a D permanent high water table soils with a claypan or clay layer at or near the surface and shallow soils over nearly impervious material These soils have a very slow rate of water transmission RUSLE The Cover Factor and Wet columns are values used in the revised universal soil loss equation RUSLE to calculate erosion The cover factor is typically a number bet
41. specific areas of concern that may be logical targets for further monitoring e Accumulated sediment load grid kilograms A total sediment load grid is created for each OpenNSPECT run for which the user chooses to calculate erosion Data sets that result from running an OpenNSPECT analysis for local effects will also include e Local runoff grid liters This grid displays the volume of runoff from each cell in the analysis area e Local pollutant grid milligrams This grid displays the amount mass of the specified pollutant that is coming off of each cell in the analysis area e Local sediment load grid milligrams This grid displays the amount of sediment mass that is eroding from each cell in the analysis area 4 1 Comparing Outputs Making comparisons of the difference in water quality between a baseline landscape and a landscape after some management scenario is the heart and soul of OpenNSPECT The Compare Outputs tool helps users easily do this by calculating the absolute change and the percentage 32 change between two different OpenNSPECT runs These runs can include local effects accumulated effects and pollutant concentration e Direct Comparison Management Baseline produces a grid of the difference between the modified scenario and the original scenario in units of the original data Zero equals no change positive numbers indicate the land use changes caused an increase and negative numbers indicate the lan
42. t based precipitation scenario or an annual precipitation scenario is selected in the Precipitation Scenario field Pollutants Erosion Land Uses Management Scenarios IV Calculate Erosion for Annual Type Precipitation Scenario K Factor C NSPECT WaianaeD ata SOILSK1 m Rainfall Factor fT Sediment Delivery Ratio GRID foptional UseGRID IEEE A a a Use Constant finches Event Type Precipitation Scenario To include erosion calculations in the analysis select the check box beside Calculate Erosion for Event Type Precipitation Scenario Annual Type Precipitation Scenario To include erosion calculations in the analysis select the check box beside Calculate Erosion for Annual Type Precipitation Scenario e K Factor Data Set This shows the K factor grid associated with the soils configuration selected in the Soils Definition drop down list The K factor is an erodibility factor needed to estimate soil loss The erodibility factor is based on soil characteristics and can be acquired from the Natural Resources Conservation Services NRCS Soil Survey Geographic SSURGO Database e Rainfall Factor The Rainfall Factor frame becomes available if the selected precipitation scenario is an annual precipitation scenario The rainfall factor also called the runoff erosivity factor quantifies the effects of raindrop impacts and reflects the amount and rate of runoff associated with the rain Rainfall factors can also
43. th fine to moderately course textures have a moderate infiltration rate and Group C soils typically sandy clay with a moderately fine to fine texture have a low infiltration rate e Cover Factor Specify a cover factor for the new land use type The cover factor is defined as the ratio of soil loss from land under specified vegetative or mulch conditions to the corresponding loss from tilled bare soil More dense cover slows water and prevents it from flowing down a slope quickly carrying sediment The lower the cover factor the better the vegetative cover is at preventing erosion The higher the cover factor the more erosion that will result in that area For example grasslands generally have a much lower cover factor than bare land because the vegetation will help prevent soil erosion e Water Wetlands Select the Water Wetlands check box if the land use type is water or a wetland This information is required to accurately calculate erosion e Pollutant Each pollutant that the user has defined within OpenNSPECT will be listed in the pollutant column This column cannot be edited e Coefficients Specify a coefficient for each pollutant that may result from this land use type Only one type of coefficient must be specified The Type 2 Type 3 and Type 4 columns can be used in cases where some phenomenon will cause the coefficients for each pollutant to change 2 4 2 Management Scenarios Use the Management Scenarios tab to change the la
44. to a different land cover class The Change Area Layer drop down list contains all defined polygon layers in the MapWindow project e Change to Class Select the new land cover class that will be applied to the polygon layer The Change to Class drop down list contains all land cover classes for the selected land cover type Pollutants Erosion Land Uses Management Scenarios Apply Change Area Layer Change To Class Insert Row Delete Current Row Note Right click the table to Append Insert and Delete Rows Run Cancel 10 Add Management Scenario There are three options available via a pop up menu to edit the management scenario parameters Access the pop up menu by right clicking within the table e Append Row Add a new management scenario to the end of the table by selecting Append Row from the pop up menu that displays by right clicking within the table In the Change Area Layer column select the polygon layer denoting the area where the land cover class will change The column contains a drop down list of all polygon layers defined in the active data frame Then select the new land cover class for the region e Insert Row Insert a new management scenario into the table by selecting Insert Row from the pop up menu that displays by right clicking within the table In the Change Area Layer column select a polygon layer denoting the area where the land cover class will change The column contains a drop
45. ween 0 and 1 13 and is essentially the ratio of soil loss from land under specified vegetative conditions to the corresponding loss from bare soil The cover factor reduces the soil loss estimate according to the effectiveness of vegetation at preventing detachment and transport of soil particles The higher the value the more erosion that occurs for example bare land has a relatively high cover factor Default values for C CAP data are provided with OpenNSPECT Provide cover factor values when creating a new land cover data set The Wet column designates whether the land cover type is water or wetland If the land cover class is water or wetland the check box in this column should be selected For any non water class the check box should be cleared This distinction is necessary for an accurate calculation of erosion Add Land Cover Type In the Land Cover Type dialog box go to Options gt New New Land Cover Type ES Land Cover Type New Land Cover Description Description of land cover Classification SCS Curve Numbers RUSLE Value Name Landclass1 Landclass2 Insert Row Delete Row wes Land Cover Type Provide a name for the new land cover type being added limit of 35 characters Description Provide a brief description less than 100 characters of the new coefficient set 14 Classification Input the grid value Value column and corresponding name Name column for ea
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