Page 35 - 2022年第53卷第9期
P. 35

Irrigationsignalanalysisandirrigatedareaextractionbasedon
                                             opticalandradarremotesensing :
                        AcasestudyofCiyouirrigationarea,LingshouCounty,NorthChinaPlain

                                                        3
                                                3
                                                                      1
                                     1,2
                                                                                   4
                        YANGYongmin ,GUTao,WUDi,LONGAihua,QIUJianxiu,LIUHongxin                  1
                               (1.ChinaInstituteofWaterResourcesandHydropowerResearch,Beijing 100038,China;
                      2.ResearchCanteronFloodandDroughtDisasterReductionoftheMinistryofWaterResources,Beijing 100038,China;
                                   3.ChinaIrrigationandDrainageDevelopmentCenter,Beijing 100054,China;
                              4.SchoolofGeographyandPlanning,SunYat - senUniversity,Guangzhou 510275,China)
                  Abstract:Currently,statisticalinvestigationisthemainapproachtoderiveirrigatedarea,withlimitedtimeliness
                  andaccuracy ,whiletheinformationonactualirrigatedareaalongsideitsspatialdistributionanddynamicchanges
                  areurgentlydemandedinwatermanagementwithintheirrigatedarea.Inthisregard,anopticalandmicrowave -
                  basedmethodisproposedfordetectingirrigationsignalandextractingactualirrigatedarea.First ,simulationswere
                  performedusingwatercloudmodelcombinedwithin - situsoilmoisturemeasurementstoquantifythechangesin
                  backscattercoefficientsduetoirrigationevents.Then,usingbackscattercoefficientsfromSentinel - 1withhighre
                  visitfrequency,amethodbasedontime - seriesdifferenceandlocalthresholdisproposed,andconductedforex
                  tractionofirrigatedareainCiyouirrigationareaofLingshouCounty ,NorthChinaPlain.Theresultsshowthatirri
                  gationeventsinspringwheatplotscanleadtofluctuationofradarbackscattercoefficientsinCbandbymorethan
                  1dB ,thusirrigationsignalscanbedetectedbyradarsatelliteswithanabsoluteaccuracysuperiorto1dB.Time -
                  seriesofradarbackscattercoefficientsanalysisindicatesthatduetoirrigationevents , significantincreaseof
                  C - bandradarbackscattercoefficientswillbefollowedbyobviousdecrease.Unlikeprecipitationevent ,localfea
                  turesareprominentinirrigation - inducedradarbackscattercoefficientsvariation.Throughfieldsurveysamplevali
                  dation ,theproposedmethodshowedoverallaccuracyof76.6% inextractingactualirrigatedarea.Theareasoffirst
                  canalirrigationduringthewheatseedlingestablishmentperiodandduringelongationperiodareabout92,000and
                  106,400acresrespectively.Inaddition,duetotheobvioustimedifferencebetweenwellirrigationareaandcanal
                  irrigationarea ,theirrigationareaofdifferentwatersourcescanbedetectedbasedonradarremotesensing,andthe
                  wellirrigationareainthestudyareaisabout39,000acres.Theproposedmethodcanprovidetechnicalsupportfor
                  applicationssuchasregionalirrigationareasurveysandbasinwaterresourcemanagement.
                  Keywords:irrigatedarea;radarremotesensing;backscattercoefficients;watercloudmodel


                                                                                    (责任编辑:耿庆斋)
































                —  1 0 8 —
                     4
   30   31   32   33   34   35   36   37   38   39   40