Global-monitoring-of-wetlands

GlobalmonitoringofwetlandsethevalueofENVISATASARGlobalmodeA.Bartscha,*,W.Wagnera,K.Scipala,b,C.Pathea,D.Sabela,P.WolskicaInstituteofPhotogrammetryandRemoteSensing,ViennaUniversityofTechnology,Gusshausstraße27-29,1040Vienna,AustriabEuropeanCentreforMediumRangeWeatherForecast,ShinfieldPark,Reading,RG29AX,UKcHarryOppenheimerOkavangoResearchCentre,PrivateBag285,Maun,BotswanaReceived20October2006;receivedinrevisedform28February2007;accepted26June2007Availableonline17March2008AbstractThispaperelaboratesonrecentadvancesintheuseofScanSARtechnologiesforwetland-relatedresearch.Applicationsofactivesatelliteradarsystemsincludethemonitoringofinundationdynamicsaswellastimeseriesanalysesofsurfacesoilwetness.Formanagementpurposesmanywetlands,especiallythoseindryregions,needtobemonitoredforshortandlong-termchanges.Anotherapplicationofthesetechnologiesismonitoringtheimpactofclimatechangeinpermafrosttransitionzoneswherepeatlandsformoneofthemajorlandcovertypes.Therefore,examplesfromborealandsubtropicalenvironmentsarepresentedusingtheanalysedENVISATASARGlobalmode(GM,1kmresolution)dataacquiredin2005and2006.InthecaseoftheENVISATASARinstrument,dataavailabilityoftherathercoarseGlobalModedependsonrequestprioritiesofothercompetingmodes,butacquisitionfrequencymaystillbeonaveragefortnightlytomonthlydependingonlatitude.PeatlandtypescoveringvaryingpermafrostregimesoftheWestSiberianLowlandscanbedistinguishedfromeachotherandotherlandcoverbymulti-temporalanalyses.Upto75%ofoligotrophicbogscanbeidentifiedintheseasonalpermafrostzoneinbothyears.Thehighseasonalandinter-annualdynamicsofthesubtropicOkavangoDeltacanalsobecapturedbyGMtimeseries.Responsetoincreasedprecipitationin2006differsfromfloodpropagationpatterns.Inaddition,relativesoilmoisturemapsmayprovideavaluabledatasourceinordertoaccountforexternalhydrologicalfactorsofsuchcomplexwetlandecosystems.�2008ElsevierLtd.Allrightsreserved.Keywords:Wetland;Peatland;Satelliteradar;Timeseries;Inundation;Soilmoisture1.IntroductionSpecificmechanismsofwatersupply