地理学科国家杰出青年基金项目交流会

Part2.Thewatershedinventory

2005-3-8Watershedmanagement--52of19ThewatershedinventoryThelifebloodofawatershedecosystemiswater.Watermovementisaffectedbymanyphysical,chemical,andbiologicalfeatureandprocesses.2005-3-8Watershedmanagement--53of19Assessingtheconditionofawatershedecosystemandtheimpactsofmanagementactionsonitisanessentialfirststepinwatershedmanagement2005-3-8Watershedmanagement--54of19Thewatershedmanagementinventoryinclude：ClimateGeologyandlandformSoilVegetationandlanduseHydrologySocialandeconomicsystems2005-3-8Watershedmanagement--55of19ClimateSolarradiation(W/m2)Degreedays(oC)Maximum/minimumairtemperature(oC)Relativehumidity(%)Dewpointtemperature(oC)Rainfallamount(mm)2005-3-8Watershedmanagement--56of19

Rainfallintensity(mm/min)Snow(mm)Snowdepth(cm)Snowcover(%)Windvelocity(m/s)Winddirection2005-3-8Watershedmanagement--57of19PrecipitationPrecipitationandinterceptionaffecttheamount,timing,andspatialdistributionofwateraddedtoawatershedfromtheatmosphere.2005-3-8Watershedmanagement--58of19PrecipitationHydrologistsviewprecipitationasthemajorinputtoawatershedandakeytoitswateryieldcharacteristics.Ecologistsrecognizetheroleofprecipitationindeterminingthetypeofsoilsandvegetationthatoccuronawatershed.2005-3-8Watershedmanagement--59of19ThreeconditionsforprecipitationTheatmospherebecomessaturatedSmallparticlesornucleiarepresentintheatmosphereuponwhichcondensationorsublimationcantakeplaceWateroriceparticlesmustcoalesceandgrowlargeenoughtoreachtheearthagainstupdrafts2005-3-8Watershedmanagement--510of19

Saturationvaporpressure–airtemperaturerelationship

ACBSaturationvaporpressure2005-3-8Watershedmanagement--511of19TypesofprecipitationFrontprecipitation(warm/coldfront)OrographicprecipitationConvectiveprecipitation2005-3-8Watershedmanagement--512of19MeasurementsofprecipitationStandardgaugeStoragegauge:1525-2540mmRecordinggaugeweighting-typetipping-bucketfloatdevicewaterleveldigitalrecordingtechniques

2005-3-8Watershedmanagement--513of19Measurementsofprecipitation

=35-45oH>1HViewofgauge2005-3-8Watershedmanagement--514of19Calculatingmeanwatershedprecipitation

ABCDA B C D4 8 10 6Arithmeticmean=(4+8+10+6)/4=7cm 2005-3-8Watershedmanagement--515of19Calculatingmeanwatershedprecipitation

Thiessenpolygon:A 4*0.28=1.12cmB 8*0.09=0.72cmC 10*0.49=4.90cmD 6*0.14=0.84cm SUM=7.58cmABCD2005-3-8Watershedmanagement--516of19Calculatingmeanwatershedprecipitation

Isohyetal:4.5*0.12=0.54cm5.5*0.25=1.38cm6.5*0.14=0.91cm7.5*0.13=0.98cm8.5*0.18=1.53cm9.5*0.14=1.33cm10.5*0.04=0.42cmSum=7.09ABCD108642005-3-8Watershedmanagement--517of19EstimatingmissingdataRatiomethodWherePc=estimatedstormprecipitationforstationC(mm);Na,Nb,Nc=normalannualprec.forA,B,andC(mm);andPaandPb=stormprec.forstationAandB(mm).2005-3-8Watershedmanagement--518of19EstimatingmissingdataDoublemassanalysis19501960197019801990AccumulatedrainfallaverageforstationsHandIAccumulatedrainfallatstationE200