Cartographic models Application of spatial operations such as buffers, interpolation, reclassification, and overlay to solve problems For example, suitability analyses; see Labs 9 and 10 •Often temporally static; values don’t change during the model period •It may include a temporal component when it compares change through time (comparing vegetation in 1990 to vegetation in 2000)
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
CartographicmodelsApplicationofspatialoperationssuchasbuffers,interpolation,reclassification,andoverlaytosolveproblemsForexample,suitabilityanalyses;seeLabs9and10
•Oftentemporallystatic;valuesdon’tchangeduringthemodelperiod
•Itmayincludeatemporalcomponentwhenitcompareschangethroughtime(comparingvegetationin1990tovegetationin2000)
2
CartographicmodelingCombinegeneraldatasets,functions,andoperationsinasequencetoanswerquestions.
Examples:-wherearethebestplacestositeasolarplant?-whereisthebestwolfhabitat?-wherearethemostvulnerablecitiestooil
increasedoil-railtransport?-whereisthebestplacetobuildanewpark?
Cartographicmodeling
Questionsascriteria:“bestplaceforparks”meanswhat?
1)Nearroads…..whatdistanceisnear…500m?
2)Nearwater,samequestion…200m?
Additionalrestrictions3)Notinwetlands(howtoidentify?),
4)Notonhydricsoils(howtodefine?)
Cartographicmodeling
Stepsfromquestiontosolution
1)Identifycriteria,relativeranking
2)Quantifythresholds,values,asneeded
3)Identify,assessdataneeds,availability,
4)Listspatialoperations,sequence
5)revisitquestion/criteria,orapply
Cartographicmodeling
Cartographicmodels
Oftenrepresentedwithflowcharts;graphicallyrepresentingthespatialdata,operationsandtheirsequence
Combinationsasanadditiveprocess
DiscreteandContinuousRankings
TheBasisforRankings
ExampleWeightings–DistancetoRoads
Example–slopesuitabilityranking
WeightingsAmongLayers:Howdoyoucombinetherankingsfromvariouslayers?Therelativeweightsamongyourinputlayerswillsubstantiallyaffecttherelativesuitabilitiesyoupredict.
DeterminingWeights
•Unscaled• Commonscale• ClientorExpertSurvey(iterative)• Rankorderweights
Weightsmustbejustified
RankOrderDeterminationofWeights
20 operations 15 data layers
20 operations 15 data layers
20 operations 15 data layers
PointstoRemember:•Problemisclearlyspecified,appropriateforGIS?•Spatialandattributeaccuracyrequired?SuchDataavailable,particularlyinclusionsandmmu?•Commoncoordinatesystem/datumsforalllayers•Adequatelayerextent?•Rasterandvectordata,conversionmethods?•Whataretheprimary“branches”ofanalysis?•Howdoyoujointhesebranchesintoananalysistree(diagram)
Related Documents
