摘要
TheKotoda-Bortan(KB)model(LiuandKotoda1998)usedforestimatingevapotranspirationwasmodified.ThemonthlyevapotranspirationforvarioussurfacesintheYangtzeDelta(118-123■,28-33■)wascalculatedusingthemodifiedmodel,andtheannualregionalaverageofevapotranspirationfrom1961to1998wasobtainedusingaweightingmethod.Thespatialandtemporaldistributioncharacteristicsofevapotranspirationwereanalyzed.Itisfoundthattheregionalaveragedannualevapotranspirationhasadecreasingtrendoverthepast40years;thevaluedroppedbyabout24mmfrom1961to1998.Themainreasonforthistendencyisduetothechangeoflandsurfacecondition.Comparedwiththecaseof1980,thecurrentproportionsofpaddyfield,farmlandandwatersurfacehavedecreasedby1.353%,4.42%and2.597%respectively,whiletheproportionsofurbanareaandnon-agriculturelandhaveincreasedby3.345%.Thesechangesclearlyresultinadecreaseoftheregionalaveragedevapotranspiration.
出版日期
2003年02月12日（中国期刊网平台首次上网日期，不代表论文的发表时间）
