中文摘要：

根据汉江流域14个气象站点1961—2011年的逐日气象资料,分别利用参数率定后的AA模型和GG模型计算汉江流域的实际蒸散发。在此基础上,采用Mann-Kendall检验法、Sen’s坡度检测法和Pettitt突变检测法对过去51 a汉江流域实际蒸散发的时空演变规律及主要气象因子的变化趋势进行分析,并探讨实际蒸散发变化的成因。结果表明,参数率定后的AA模型和GG模型对汉江流域实际蒸散发的模拟结果基本一致;汉江流域1961—2011年平均实际蒸散发总体上呈现自东南向西北逐次减少的空间分布特征;整个流域的多年平均实际蒸散发呈现显著下降趋势,并于1979年发生显著性突变;显著下降的风速和日照时数是导致汉江流域年实际蒸散发显著下降的主要原因。

英文摘要：

Based on daily meteorological data from 14 stations in the Hanjiang River Basin from 1961 to 2011,the AA model and the GG model with calibrated parameters were used to calculate the actual evapotranspiration in the Hanjiang River Basin.On this basis,the Mann-Kendall statistical test,Sen＇s slope test,and Pettitt test were selected to detect the spatial and temporal variations of actual evapotranspiration and the trend of major meteorological factors over the last 51 years,and the causes of these variations were also explored.The results show that the actual evapotranspiration calculated by the AA model and the GG model with calibrated parameters was basically the same.The annual average actual evapotranspiration showed a decreasing trend from the southeast to the northwest in the Hanjiang River Basin from 1961 to 2011.In addition,the annual average actual evapotranspiration presented a significant downward trend from 1961 to 2011,with a significant mutation occurring in 1979.A significant decrease of wind speed and sunshine duration was largely responsible for the significant decrease of actual evapotranspiration in the Hanjiang River Basin.