【摘要】 为了给全面评估黄土高原地区大规模实施退耕还林还草的生态效应提供依据,基于NASA发布的空间分辨率为500 m的MOD16A2蒸散发数据产品,分析了黄土高原以及黄河中游典型流域2001—2017年实际蒸散发量时空变化特征。结果表明:黄土高原年均实际蒸散发量从西北向东南递增,多年平均季节蒸散发量空间分布格局与年平均蒸散发量分布格局基本一致,季节蒸散发量由大到小顺序为夏季>秋季>春季>冬季;实施退耕还林还草工程以来,黄土高原年均蒸散发量以8.23 mm/a的速率显著增加,多年平均蒸散发量为278.71 mm;黄河中游各典型支流2001—2017年蒸散发量均呈现增加的趋势,延河流域增速最大(为12.96 mm/a),皇甫川流域增速最小(为4.34 mm/a);不同流域实际蒸散发量差异较大,渭河干流年均蒸散发量最大(为388.26 mm),皇甫川流域年均蒸散发量最小(为153.71 mm)。更多还原

【Abstract】 In order to provide a basis for comprehensive assessment of the ecological effects of large-scale conversion of "Grain for Green" in the Loess Plateau, based on NASA’s MOD16 A2 evapotranspiration product(spatial resolution 500 m), this paper analyzed the temporal and spatial variation characteristics of actual evapotranspiration(ET) in the Loess Plateau and typical watersheds in the middle Yellow River from 2001 to 2017. The results show that the annual average ET and the annual average seasonal evapotranspiration of the Loess Plateau are both increased from northwest to southeast. The seasonal evapotranspiration follows the order of summer > autumn > spring > winter; Since the implementation of "Grain for Green", the annual average evapotranspiration of the Loess Plateau shows an increasing trend of 8.23 mm/a and the annual average evapotranspiration is 277.76 mm; The annual average evapotranspiration shows an increasing trend from 2001 to 2017 for all watersheds in the middle Yellow River and that of the Yanhe River basin increases with average increasing rate of 12.96 mm/a; the annual average evapotranspiration of Huangfuchuan shows more gently increasing trend with average increasing rate of 4.34 mm/a. Among the main tributary catchments, the annual average ET value of Weihe River is the highest(388.26 mm) and that of Huangfuchuan is the lowest(153.71 mm).更多还原