1999 年以来黄土高原实施了大规模的植树造林工程, 但该工程是否加剧了区域水资源压力引发了社会的广 泛讨论。为科学解析黄土高原水循环演变过程, 基于 Cho udhur y2Yang 公式计算了黄土高原泾河流域 2000- 2014 年蒸散发变化, 并定量区分了气候因子和下垫面因子对流域蒸散发变化的贡献。研究结果表明: 退耕还林工程实施 以来, 泾河流域实际蒸散发呈下降趋势, 年均降幅为- 21 28 mm; 降水是该流域蒸散发变化的主导因子, 其平均贡献 率达到 761 8% , 远大于潜在蒸散发( 401 8% ) 和下垫面变化( - 171 5% ) 的影响。基于 Choudhury2Yang 公式的蒸散 发归因识别方法, 对定量区分气候和下垫面变化对流域蒸散发的影响具有重要的科学意义。

A lar ge2scale affo restation pro ject has been implement ed in the Lo ess Plateau since 1999, but w hether the pro ject has intensified r egional water supply pr essure is being w idely debated. In o rder to scientifically analyze the w ater cycle process in the Lo ess Plateau, this study calculated the evapot ranspir atio n changes of t he Jing he Riv er basin based on the Choudhury2Yang e2 quation during 2000 to 2014, and quant itativ ely dist ing uished the co nt ributio n o f climatic facto rs and that o f underlying surface facto rs to ev apo transpiratio n chang es. Results show ed that: since the implementat ion o f the afforestation pro ject, the ev apo trans2 pir atio n o f the Jing he River basin has slig ht ly declined at an annual averag e rate of - 21 28 mm. Precipit ation was the dominant facto r o f ev apo transpiratio n chang es in the study period, w ith an averag e co ntribution rate of 761 8% , w hich was far g reater than the contribut ion of potential evapotr anspir ation chang e ( 401 8% ) and underly ing surface change ( - 171 5% ) . This st udy show s that the Choudhury2Yang equatio n has impo rtant scientif ic sig nificance fo r quantitativ ely distinguishing the effects of climat e and underlying surf ace chang es on ev apo transpirat ion.

国家重点研发计划( 2016YFC0401407) ; 国家杰出青年科学基金( 51625904)