chapter  12
17 Pages

Surface modelling and spatial interpolation

Earlyoninthisbookwemadeadistinctionbetween object-basedandfield-basedmodels,notingthatthe formerwereprimarilyconcernedwiththeformand locationofindividualphenomena,whilethelatter wereconcernedwithrepresentingthecontinuousdistributionofphenomena.Inthischapterwepursue thesubjectofthefield-basedviewofphenomena, lookingatthewaysinwhichtheyarerepresentedand analysedinsurfacemodels.Theterm'surfacemodelling'isusedtoheretorefertoarangeoftechniques formanipulatingdatathatareregardedasrepresentingafield.Aswehavepointedoutearlier,inthe geographicalsciencesthereisageneraldistinction betweentwotypesofsurfacemodel,differingaccordingtothephenomenarepresented.Thefirstisforthe purposeofmodellingphysicalsurfacesofterrainand geology.Thesecondisformodellingabstractsurfaces whichrepresentthedistributionoflesstangible,spatiallyvariablestatistics.Manysurfacemodelling techniquesarecommontothesetwoapplications. Terrainmodelscaninfactberegardedasaclassof statisticalsurfacemodelinthattheyarebasedona sampleofnumericalobservationsfromwhichthe 'real'surfacemustbeinferred.