地理坐标系与地图投影1课件

MapProjectionsandTypesMapProjectionsandTypes1CartographyTheartandscienceofmakingmaps,includingdatacompilation,layout,anddesign.Alsoconcernedwiththeinterpretationofmappedpatterns.AstonetabletfoundinacaveinAbauntzintheNavarraregionofnorthernSpainisbelievedtocontaintheearliestknownrepresentationofalandscape.CartographyTheartandscience2MapsVisualrepresentationoftheearth’ssurfaceorthephenomenon(anyobservableoccurrence)thatoccurontheearth’ssurface.MapsVisualrepresentationoft3MapScaleThedegreetowhichamap“zoomsin”ontheareaitisrepresenting.Scaletellsyouwhatextenttheportionoftheearthrepresentedonthemaphasbeenreducedfromitsoriginalsizetofitonthemap.MapScaleThedegreetowhicha4Forexample,1inchonamapmayequal10milesintherealworld.Thatscalemightbewrittenas1inch=10miles.Sometimes,scaleisindicatedasafraction.“1/10miles”or“1:10miles”means1inchonthemapequals10milesintherealworld.Forexample,1inchonamapm5THISISTHETRICKYPARTCounterintuitivepartofmapping: “LARGE”OR“SMALL”scale.Themore“zoomedin”themapisonanarea,thelargerisitsmapscale.large-scalemapdepictsasmallerareaTheless“zoomedin”themapisonanarea,thesmallerisitsscale.Small-scalemapdepictsalargerareaTHISISTHETRICKYPARTCounter6地理坐标系与地图投影1课件7地理坐标系与地图投影1课件8MapProjectionsMapProjections9EarthisROUND!EarthisROUND!10So?Transformingsomethingsphericalintosomethingflatmeansthatthe2-Dimagewillneverexactlyrepresentwhatisvisibleinthree-dimensions.Geographersusenumerousmathematicalequationstoproducemapprojections.So?Transformingsomethingsphe11Allflatmapshavesomedistortionintheirrepresentationof:DistanceShapeAreaOrdirection.Allflatmapshavesomedistor12TypesofProjectionsEqual-area(orequivalent)projections:mapsthatmaintainareabutdistortotherproperties.Conformal(ororthomorphic)projections:mapsthatmaintainshapebutdistortotherproperties(itisimpossibletohaveaprojectionthatisbothconformalandequalarea).Azimuthalprojections:mapsthatmaintaindirectionbutdistortotherproperties.Equidistantprojections:mapsthatmaintaindistancebutdistortotherproperties.TypesofProjectionsEqual-area13MercatorProjectionCylindricalmapprojectionUsefulfornavigationbecauseitmaintainsaccuratedirectionFamousfortheirdistortioninareathatmakeslandmassesatthepolesappearoversizedMercatorProjectionCylindrical14MercatorProjectionMercatorProjection15PetersProjectionCylindricalmapprojectionAttemptstoretainalltheaccuratesizesofalltheworld’slandmassesSometimesusedasapoliticalstatement-thatweshouldrefocusourattentiontothetropics,hometolargelandmassesandmanyoftheworld’spoorestcountries.PetersProjectionCylindricalm16PetersProjectionPetersProjection17FullerProjectionMaintainstheaccuratesizeandshapeoflandmassesCompletelyrearrangesdirectionsuchthatthefourcardinaldirections(north,south,east,andwest)nolongerhaveanymeaning.FullerProjectionMaintainsthe18FullerProjectionFullerProjection19RobinsonProjectionAttemptstobalanceseveralpossibleprojectionerrors.Doesnotmaintaincompletelyaccuratearea,shape,distance,ordirection,butitminimizeserrorsineach.UsedbyNationalGeographicRobinsonProjectionAttemptsto20RobinsonProjectionRobinsonProjection21AzimuthalProjectionPlanarFormedwhenaflatpieceofpaperisplacedontopoftheglobeand,asdescribedearlier,alightsourceprojectsthesurroundingareasontothemap.EithertheNorthPoleorSouthPoleisorientedatthecenterofthemapwhichgivestheviewertheimpressionoflookingupordownattheearth.AzimuthalProjectionPlanar22AzimuthalProjectionAzimuthalProjection23MapTypesMapTypes24ReferenceMapShowlocationsofplacesandgeographicfeatures.ReferenceMapShowlocationsof25ThematicMapTellastoryaboutthedegreeofanattribute,thepatternofitsdistribution,oritsmovement.ThematicMapTellastoryabout26ThematicMapThematicMap27ContourMaps(Isopleths)Isolines-Linesonamapdepictingareasofsameorlikevalues.Contourmapsuseisolines,orcontourlines,todepictwherethesameelevationexists.The

contourinterval

ofacontourmapisthedifferenceinelevationbetweensuccessivecontourlines.ContourMaps(Isopleths)Isolin28ContourMapsContourMaps29ProportionalSymbolsMapTheproportionalsymboltechniqueusessymbolsofdifferentsizestorepresentdataassociatedwithdifferentareasorlocationswithinthemap.ProportionalSymbolsMapThepr30ProportionalSymbolsMapProportionalSymbolsMap31ProportionalSymbolsMapProportionalSymbolsMap32Adotmaybeusedtolocateeachoccurrenceofaphenomenon.Whereappropriate,adotmayindicateanynumberofentities,forexample,onedotforevery100voters.DotMapMilitaryfamiliesinOhioAdotmaybeusedtolocateea33ChoroplethMapShowsstatisticaldataaggregatedoverpredefinedregions,suchascountiesorstates,bycoloringorshadingtheseregions.Forexample,countrieswithhigherratesofinfantmortalitymightappeardarkeronachoroplethmap.ChoroplethMapShowsstatistica34ChoroplethMapChoroplethMap35CartogramA

cartogram

isa

map

inwhichsomethematicmappingvariableissubstitutedforlandareaordistance.Thegeometryorspaceofthemapisdistortedinordertoconveytheinformationofthisalternatevariable.CartogramA

cartogram

isa

map

36CartogramCartogram37CartogramCartogram38CartogramCartogram39GISmapAgeographicinformationsystem(GIS)integrateshardware,software,anddataforcapturing,managing,analyzing,anddisplayingallformsofgeographicallyr