中文摘要：

基于站点气象数据及0．1°×0．1°栅格气象数据对黑河流域PET进行估算．利用Spline插值方法，将站点数据计算得到的PET进行空间插值，并与栅格数据计算获得的结果对比验证，分析PET的空间变化特征．利用MannKendall非参数检验方法，对站点PET及气温序列进行趋势分析．结果表明：1）Spline空间插值获得的PET空间分布与栅格数据计算获得的结果基本一致，可用于PFT空间变化特征分析；2）空间上，黑河流域多年平均PET年值和季节值均呈现出从西南到东北逐渐增加的趋势；3）年平均气温在15个站点均呈现出明显的上升趋势，而PET在多数站点呈现下降趋势，黑河流域可能存在“蒸发悖论”现象．

英文摘要：

On the basis of the daily meteorological data at 15 meteorological stations and 0.1°×0.1° meteorological grid data in the Heihe River basin, the long-term trends of potential evapotranspiration （PET） and air temperature were analyzed by using the Mann-Kendall test method. The ＂evaporation paradox＂ was also investigated at 15 sites. The results show that. 1） mean annual and seasonal value of PET in the Heihe River basin generally increased from southwest to northeast. 2） Mean annual air temperature exhibited significant increasing trends at all 15 sites, while the mean annual PET exhibited decreasing trends at most of the sites （except 5 sites）. Therefore, the evaporation paradox does exist in the Heihe River basin. 3） The evaporation paradox phenomenon is not consistent spatially and temporally. The stations with ＂evaporation paradox＂ are mainly located in the middle reaches.