土地利用变化对蒸散发的影响是水文等相关领域研究的热点问题。本文选取淮河上游息县流域作为研究对象，基于1990s和2000s土地利用资料分析土地利用变化，应用分布式双源蒸散发模型计算基于网格的蒸散发能力，分析土地利用变化对不同典型年不同时间尺度蒸散发能力的影响。结果表明：从1990s到2000s，30%流域面积的土地利用发生了变化，其中水田转变为旱地占比最大；发生蒸散发能力变化的大部分网格的季尺度蒸散发能力在不同典型年均呈现不同程度的减小，且夏季最为显著；发生蒸散发能力变化的大部分网格的年尺度蒸散发能力在不同典型年也均呈现不同程度的减小，且减小幅度依枯水年、平水年、丰水年递减。论文研究成果可为变化环境下水循环演变研究提供支撑，对水土地资源的开发利用也具有参考价值。

The influence of land use change on the evapotranspiration is a hot issue in the hydrology and other related areas． The paper selects Xixian Basin in the upper reaches of Huaihe river as the study area，and analyzes the land use change on the basis of data of land use in 1995 and 2000． Then，it analyzes the effects of land use change on potential evapotranspiration in different typical years and different time scales based on the calculated values of evapotranspiration in each grid with the application of dual-source potential evapotranspiration distributed model． The results show that: from 1995 to 2000，the land use in 30% of the watershed area has changed，and the largest proportion of all is the transition from paddy field to dry land; the seasonal potential evapotranspiration in great mass of areas in which potential evapotranspiration has reduced to different degrees in different typical years，especially in summer; the annual potential evapotranspiration in great mass of areas in which potential evapotranspiration has reduced to different degrees in different typical years，and the dry year is the most significant． The research results can provide support for the study of water cycle evolution in the changing environment，and also have reference value for the development and utilization of water and land resources．