Visual Resource Assessment A User Guide MOE Manual 2
Contents
1. SCENIC ASSESSMENT UNIT VISUAL RESOURCE MANAGEMENT CLASS I to X high to low Y R rehabilitate IZ E enhance FIGURE 4 9 Slocan Valley Landscape Unit Management Class Structure A Summary Map A composite elements score of contrasts with all indicated the degree of magnitude of impact occasioned by the proposed development Contrast rating scores as outlined can be related to VR Management Classes by assigning maximum and minimum allowable rating scores within each class Table 4 6 VR Management Class Reguirements is used for this purpose If the composite visual impact rating score tabulated summary on Field Form 2 as a sum of overall element ratings and scale dominance factors is too high to be accomodated in the Management Class the project must be modified by design re located in a lower VR Management Class area or disallowed In the example shown severity was judged moderate with a tota impact score of 33 Since Management Class 111 reguirements range from 24 to 35 the project is acceptable It is important to note that visual contrast rating assignments as outlined above will vary within each VRMA and cannot be categorically specified for the province at large until adeguately field tested under actual conditions 4 7 2 LANDSCAPE CONTROL POINTS One effective system for office and field checking probable impacts of development on the visual resource is by establishing2. tion and later translated to sketch form as noted The above system is less costly than computer assisted methods but limited to projects where digital information is either unavailable inappro Its main value lies in depicting above ground vegetation and structures priate or unnecessary with scale and perspective accuracy beyond that of such systems as Perspective Plot and Preview which depict trees rocks and objects in symbolic form only More specific current and past project information may be obtained from the B C Parks and Outdoor Recreation Division the British Columbia Institute of Technology Angelo 1979 and the School of Forestry University of British Columbia Young 1978 66 FIGURE 4 14 Simulation Technique An Example of Application in British Columbia Original Drawings by Rina Pita 4 7 5 SUMMARY Although the four methods of determining visual impact predictions appear to be fragmented and somewhat complex they are not unrelated Basically the Contrast Rating System can be given greater objectivity by supplementing assigned and weighted values with the other three methods depending upon the nature scale and intent of the 67 proposed activity and its consequent impact Developing rating skills in contrast estimation is the key to conducting effective visual impact predictions This skill can only be gained by actual on the ground applications of methodologies outlined t ogi
3. 1 Synonymous with Key Observation Points KOP as outlined in the User Guide 64 drawings both in the field and office However until more areas in British Columbia are digitized for computer entry the Landscape Control Point System remains a viable method for assessing visual impact predictions in conjunction with field contrast ratings and VAC studies For a more detailed outline of the system see Litton 1973 4 7 3 COMPUTER ASSISTED PROGRAMS Computer graphic systems now available for illustrating viewed areas times seen and impact frequencies include the following Preview Perspective Plot and Mosaic Viewit Viewit is capable of delineating terrain visible from both single and multiple observer points demonstrating viewed areas times seen and impact frequencies Travis Elsner et al 1975 It can also depict slope and aspect data in varying degrees of shaded patterns e s 0 5 0 s 0 5 onen yd 1 oeoe dd yee dID zu wed z 22000006 22210022222290086086 6006 2242010696980 22002222 2222090600 6007290907722222 wacacassor2 2222 Hath a HTTP SAS 945 Hit litsaeottiiittsauvoesnunui n im 1 1 2 3 9 0 3 5 s FIGURE 4 11 Viewit An Example of Application al 1976 Perspective Plot is used largely for selection of cut blocks in forested areas where visual imapct can be determined from varying observer points and from different azimuth angles Twito 1978 It places the propos
4. Modified from USDI Bureau of Land Management 1980 and Sheppard et al 1979 VISUAL RESOURCE CONTRAST RATING SHEET Project Name Sewage Treatment Plant Location vap NTS F2EF SE scale 50 000 Regional District Central Kao tenes Strategic Planning Area Konteney Slocan Section Range Township Longitude uT 30 Latitude 49 340 EXAMPLE ONLY soode area Sketch Map vem O Glumb Mie Landscape Unit Cost lega Evaluated By My Checked By Fz Visual Resource Management Class UL Key Observation point Ior 2 Characteristic Landscape Element Descriptors Comments inter en BUG de steep sound Site Mod Contre of Regularity continuity Little we de fn lard form Inreg Cont iuit he vue chrome Crey fe deep braun Glacia Hill over beimoc c Clarity grain Seil texture not evident Sram KoP ee YN lard farm subord in 9 but rises above Gita Regular Simple vertical DF WRC 4 ospen LAND WATER Regularity simplicity orientation Direction regularity a edge character Ne riharian dehnt Edges D rregulas ie atac chron Hve deep green Valve Medium Chrome dv if Clarity grain A Course textured dense even arde red Size di I a objects s TtT Basic conif 279 qraw to lt of not domin Regularity simplicity or
5. ja koni Man survives by taking in four kinds of nourish ment food water air and impressions of his environment Ouspensky 1968 Chapter Separator Photo PLATE 5 1 Farly morning mists rise over fenced meadows in this rural B C scene B C Ministry of Environment photo 5 MANAGEMENT OPTIONS In the final analysis decisions to allow or disallow development in visually sensitive areas are essentially political but hased on economic factors as well This may and often does present problems where aesthetics are not given sufficient consideration Thus it is of great importance that descriptive inventory and subseguent visual evalua tions portray the conseguence s of any development as they will affect visual quality in economic as well as aesthetic terms Management must then exercise options for its placement in the land scape In some cases for example a transmission line right of way or coal extraction operation places little demand upon a landscape rarely seen or one sufficiently diverse to carry the operation with little visual impact At other times various management options will need to be reviewed These fall into the following general categories mitigation enhancement rehabilitation alternate site locations or disallowance of the project In all instances it should be the aim of the visual analyst to work toward accommodation of development in the landscape with as little disturbance as possible to i
6. landscape control points Litton 1973 In this method a set viewpoint from which the landscape would normally be seen is established and mapped Drawings from this point can be made and used to predict changes Basically the method involves setting up cross sectional diagrams from a point or points of observation to the determine seen and unseen areas subject area to As with contrast ratings it is essential in KOPs which the proposed development would be seen by the greatest number of people for the greatest period of time Lines are then drawn on the map from one KOP s Figure 4 10 to ridgelines or this system to establish or points from or several 63 Sightline N VAN aa SS Computer Derived Viewshed Boundary NNN LET N Z ANS Scale 1 40 000 FIGURE 4 10 Landscape Control Points Adapted From B C Forest Service Landscape Handbook 1982 points of highest elevation within the line of vision A vertical scale is then made of points of intersection with contours plotted This should reveal in section areas seen and not seen from each KOP at a topographical level Tree heights must then be estimated to give a more precise definition of seen or unseen areas This informa tion can be gained from forest cover maps obtainable from the B C Ministry of Forests The main difficulty with the landscape control point system lies in the time reguired for
7. points 3 Computer graphics 4 Simulation These procedures are discussed at some length in the following section 4 7 1 CONTRAST RATINGS Contrast ratings based on previous scenic quality evaluations reveal existing features and 59 their respective elements that will be subject to the greatest visual impact The degree of contrast with basic landscape patterns brought about by a specific development is the primary criterion for determining suitability or adaptability of such a proposal within each designated VR Management Class Contrast ratings should be made from key observation points KOP or points that will be commonly used by observers The following factors are to be considered Distance Foreground site locations hold highest impact potentials Angle of observation As the angle nears 90 degrees it is most critical Length of time during which proposed project will be viewed There may be a need for short and long term objectives since some projects are self mitigating e g dam construction and strip mining Relative size or scale created by projects Season of year indicating heaviest use Lighting Sidelighting is best for accurate contrast evaluation PLATE 4 21 This sewage treatment plant within VRMA 14 B meets Class III VR Management requirements B C Ministry of Environment photo See page 62 60 ER nn TABLE 4 7 Proposed Field Form 1 Assigning Visual Contrast Ratings
8. 4 7 VISUAL IMPACT PREDICTIONS Where assessments of proposed project impacts are being made with a specific project in mind public awareness and sensitivity will likely be increased Public value judgements may well be coloured by the threat of development In these cases it must be made very clear whether the public or the professional involved is being asked to a assess the inherent quality of the landscape itself or b assess the sensitivity of the land scape to a specific development In answer to the above once VR Management Classes have been established by inventory and assessment a considerable degree of guidance can be given proposed developments as they arise Thus development can be avoided in highly sensitive areas or modified by specific design guidelines to reduce visual impacts Visual impact predic tions are important at this point to determine if a development should occur and where Visual impact predictions are based on the compatibility or misfit between development alter natives and the landscape s visual quality i e its relative sensitivity to alteration of its inherent visual characterics by management activity However if descriptive inventory and assessment factors have not been pre determined visual impact predictions will be difficult to carry out There are four basic procedures for conducting visual impact predictions 1 Contrast Ratings as modified from BLM 2 Establishing landscape control
9. ed cut block in perspective outline by tree symbols and is highly manipulative This program is written specifically for use on desktop computer systems such as the Hewlit Packard 9845 or Wang 2200 LVP The system has been further developed to depict utility poles and lines road cuts water storage areas and similar projects where ditigal control can be obtained see Nickerson 1980 vo LEVEL LINE OF SIGHT 18 O INCHES ABOVE FRAME VIEH DIST 15 INCHES BT Ar PERBPECTIVE plot FIGURE 4 12 Perspective Plot An Example of Application Preview in addition to rendering perspective diagrams from digitized data is capable of graphi cally illustrating vegetative cover rock outcrops water bodies and ground cover as well Myklestad et It has proven useful in selection of suitable ski slopes borrow pits road locations and cut block proposals FIGURE 4 13 Preview An Example of Application in British Columbia Source Angelo 1979 4 7 4 SIMULATION Visual predictions may also be made through simulation which can either be photographic or mechanical and often combines well with computer graphics In this rapidly developing field actual predictable results of placing a management activity within the landscape can be seen Blair 1981 Black and white or preferably colour photographs of the project area are projected and PLATE 4 22 Visual impacts of cuts fills and alignment can be simulated b
10. ientation Simple jew pro file Grm boo Direction regularity Horia dominant largely Surface areas 5 continuity simplicity blend well W ov erovFdh vg s ilu eon N trace 5 fan ia bere hal chroma Kay ul Peete Com c Untreated wood auras Size height width Observer above frem KOPA Thys low VAC surrounding areas but lew profile mot inmpetetle wi surround Define characteristic a b landscape regional Londscape unit dissected z Columb amp e n topeg lnteciae wet bel setting etc stengly by rell na to rugged vee te J Jauch b 9 Texture Scale STRUCTURES VEGETATION General Description Spatial Composition 1 Refer to Chapter II Concepts Adapted from VSDI Bureau of Land Management 1978 and Smardon et al 1982 Expansive bounded area enclosure visual unit a fe ty moderate ty focal din 5g of views of river thus highds sensitiyity n Uemwina Focal feature enclosed panoromic canopied weak to strong LANDSCAPE 61 TABLE 4 8 Proposed Field Form 2 Establishing Contrast Rating Scores for Project Visual Impacts Modified from Sheppard et al 1979 2 Relative Importance of Visual Elements in Contrast Ratings Overall Rating Procedure Multiply weighting assigned to each visual element against degree To arrive at an Overall Overall Overal
11. l or contrast i e strong 3 moderate 2 weak 1 and none 0 Rating one must review the Element Element Contrast Rating box 1 Visual and use the criteria listed Ratings scores Elements amp Introduced or Modified Components below Weighted Zi High Values Land Wate Vegetation Structures igh Moderate Overall High if Color 1 3 components high Low ja Color High 12 High or 3 components None Contrast Moderate Moderate medi um High 4x Low Low Moderate Wei ghti Form er gnelng None 0 None Overall Medium if Lou Form High High High 1 2 components atk Contrast Moderate Moderate Moderate medium With no High 4x low pee low higher ratings Mode iat Weighting None None None Line LOW Line High High High Overall Low if None Contrast Moderate Moderate Moderate 1 3 components High 3x Low LOW L w low with no higher He t Weighting None None None ratings Texture P e Texture High High High Hone Contrast Moderate Moderate Moderate Overall None if High 2x Low Low Low all components Moderate Weighting None None None None Scale Low scale High High High pone Contrast Moderate Moderate Moderate 3x Low Low Low Total Contrast Weighting Score Composite Visual Impact Severity Add the score from box 2 Overall Contrast Rating to the score from box 3 Scale Dominance to get the Composite Visual Impact y Severity Number Compare the CVIS Number with the accompanying Co dominate table to choose the Sensitivity Class Com
12. l basic quality ilnformation relateed to form line colour texture and scale At this level of assessment the characteristic landscape is defined in terms of descriptive inventory This may or may not have been done for the entire VRMA These data are then related to the proposed project in terms of evident contrasts VRMA Field Form 2 Table 4 8 is used for this purpose Usingf this form the sewage treatment plant is compared with existing site conditions element by element feature by feature according to the degree of contrast involved e g strong 3 moderate 2 low 1 and 0 no contrast Thus the element s weighted value multiplied by the degree of contrast eguals the magnitude of visual impact Weighted values for each element form line color texture and scale are based on its significance in the landscape as determined by scenic guality levels sensitivity levels and distance zones For example in this case the sewage treatment plant contrasted moderately 2 with the surrounding landforms 4 for a rating of 2 x 4 or 8 while it contrasted strongly 3 in texture 2 with the surrounding vegetation for a rating of 2 x 3 or 6 Table 4 5 Example not a plan for illustrative purposes only Legend SCENIC QUALITY RATING A high B moderate C low SENSITIVITY LEVEL H high M moderate L low DISTANCE ZONES form KOP s fg foregound mg middleground bg background ss seldom seen
13. oject area by design
14. posite Visual Impact Severity Major object in confined setting Dominate One of several major objects or major object in an unconfined setting Significant object relative to setting Subordinate Small object relative to setting Insignificant Comments Treatment plant could be brought more Closely m line win V Class Class Class OL VRMA by adoitimia Screening fron KOP 4 Class V and V R and V E Severe Project Name Does the project meet the Visual Resource Management Class Reguirement Project Visual Impact Visual Resource Management Class Reguirement maximum No C Assessor Date JQ i10 82 62 Each VR Management class describes a different degree of modification allowed in the basic elements of the landscape The primary character of the landscape should be retained regardless of the degree of modification allowed A theoretical project will serve as an example Plate 4 21 illustrates a sewage treatment plant within VRMA 14 B but a proposal for its expansion has been initiated by the Regional District The existing plant requires a visual contrast rating to determine whether or not it meets the requirements of VR Management Class 111 into which it falls The facility is in place Completing the proposed field form 1 Table 4 7 for assigning visual contact ratings is the first step in the assessment It sdhould be filled out in the field where direct observations can revea
15. ts natural qualities and in accordance with provincial and regional requirements since such development may well be necessary and desirable for our economic and social well being 5 1 MITIGATION This option can usually be carried out by means of project design A harsh exterior can be softened by wood or masonry reflecting the colour hue and intensity of the surrounding landscape Storage tanks can be painted utility towers modified vertical buildings reduced in scale Architectural engineering and landscape architec tural treatments may often be the only requirements needed to bring the proposed development up to acceptance within the specified minimal management class requirement Cost factors may preclude such treatment in which case compensation will be See B C Committee 1980 and B C Mines and Petroleum Resources 1982 for clarifica reguired Environment and Land Use Ministry of Energy 69 tion of energy and linear development application procedures in British Columbia PLATE 5 2 Structural harmony and carefully textured surfaces combine to mitigate the visual impact of this industrial complex B C Ministry of Environment photo n T1 mn19 P3G PLATE 5 3 The southern approach to Cranbrook could be greatly enhanced by the introduction of vegetation screening and ground cover 5 2 ENHANCEMENT Another option is enhancement of visual attributes of a project or pr
16. y computer graphics if digital terrain data is available 65 enlarged on a screen The proposed development can then be drawn onto the enlarged screen or photo graphic format or another photograph of the proposal superimposed on the area photo In large areas contrast ratings coupled with simulation and computer graphic displays can be very effective determinants of probable impact levels The use of visual simulation methods in British Columbia has been minimal due largely to the lack of a digitized contour data base and limited technical experience with the system Figure 4 13 illustrates the recent use 1979 of Preview for simulation of a proposed ski develop ment In a more recent example the B C Parks and Outdoor Recreation Division employed photo graphy sketches and balloon assisted simulation to graphically depict the visual effect a proposed power transmission line would have within an existing park area Figure 4 14 top is a sketch of the area as it presently exists Figure 4 14 bottom is a simulation of the same area as it would likely appear after clearing grading and installation of power poles Clearing widths and pole locations were obtained from Provincial highway and B C Hydro engineers and located in the field Actual pole heights were then simulated by the use of balloons which were released at each pole location then allowed to rise to the actual pole height Photographs were taken of the simula
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