中文摘要：

蒸散是水循环过程重要的分量,分析鄱阳湖流域蒸散的时空格局及影响因子作用对流域水资源合理利用和提升流域生态服务功能具有重要意义。以MODIS产品数据为主要数据源,应用地面温度-植被指数三角关系法反演了鄱阳湖流域2000～2009年的实际蒸散量,分析了流域蒸散的时空分布特征及主要气象因子对流域蒸散的影响。结果表明：（1）鄱阳湖流域蒸散具有很强的空间异质性,蒸散较大的区域位于湖区水域和流域森林分布区域,而湖区周围和流域中部的农田和草地蒸散相对较小。2000～2009年流域年均蒸散量为795mm。2003、2004、2007和2009年的枯水年份,蒸散值较高,变化范围为802～890mm;（2）鄱阳湖流域各子流域年蒸散量为666～1 031mm,其中饶河和修水流域蒸散量高于其他流域,这是由于这两个子流域林地所占比例较高（大于70%）。流域蒸散占降水的比例为0.4～0.7,从年尺度上整个流域仍表现为水分盈余,但年内分配不均;（3）流域蒸散与辐射和气温呈显著正相关关系（P〈0.01）,而蒸散年内分布格局则与降水格局有关,表现为月降水距平越小,月蒸散量越大。在枯水年份,降水格局对蒸散的影响尤为显著。

英文摘要：

Evapotranspiration（ET） is a key component in hydrological cycle.Understanding of spatiotemporal variation of ET is of highly valuable to basin-scale management of water resources and effective promotion of ecological services in the Poyang Lake Basin,China.This study applied the surface temperature-vegetation index triangle method to retrieve ET using the MOD erate resolution Imaging Spectroradiometer（MODIS） data over the Poyang Lake Basin for the period from 2000 to 2009.The retrieved ET was validated with in situ observation data and basin-scale water balance approach.The results revealed the spatial and temporal variations in ET over the area.ET was higher for water surfaces and forestlands,but lower for agricultural fields and grasslands surrounded the Poyang Lake or located in the central basin.The annual ET was 795 mm on average over the basin for the period.The annual value was relatively higher for dry years including 2003,2004,2007 and 2009,with a range from 802 mm to 890 mm.In addition,the annual ET was sub-basin dependent,ranging from 666 mm to 1031 mm.ET was higher in the Raohe and the Xiushui sub-basin than the others,which was attributed to the high forest cover by more than 70% over the two sub-basins.The ratio of annual ET to precipitation ranged from 0.4 to 0.7,indicating the water surplus with seasonal variation.Statistical analysis demonstrated that ET had a significantly positive relationship with net radiation and air temperature（P0.01）.Seasonal ET showed negative pattern with precipitation,especially for a dry year.