中文摘要：

以淮河流域为研究对象,选择分布式水文模型HMS,结合GIS技术,构建了分布式陆面-水文耦合模型（LSX-HMS）。利用实测水文资料进行参数率定和模型验证,确定性系数达0.791～0.854,表明该耦合模型在淮河流域具有较好的适用性,能进行土地覆被变化下的水文响应研究。采用极端土地利用/覆被法构建了5种土地覆被情景,利用LSX-HMS模型分析了各情景下的水文过程。结果表明：常绿阔叶林覆被情景下的蒸散发量和径流量变化最为显著,年均蒸散发量增加5.6%,年均径流深减少16.7%;草地覆被情景对增加径流量作用较为显著,年均径流深增加6.9%;在枯水年,草地覆被情景下的土壤含水量变化较为剧烈;对径流量的空间模拟表明：各情景下径流量的空间分布差别较大。研究成果为淮河流域水土资源合理开发利用、调配和管理提供依据。

英文摘要：

Using the distributed hydrology model system （HMS）and Gographical Information Systemand the technology of remote sensing for data patial analysis,a land surface-hydrology coupled model （LSX-HMS） was constructed in the Huaihe river basin.Measured hydrologyic data were used to calibrate and validate the model. The Nash-Sutcliffe coefficient for hydrologic simulations ranges from 0.791 to 0. 854, indicating that LSX-HMS can be used for studying hydrologic processes responses to land use and cover change （LUCC） in the Huaihe river basin.Five extreme land cover scenarios are constructed with each comprising of one single type of land cover in the Huaihe river basin.The hydrologic processes for each cover scenario are simulated by using LSX-HMS.The simulated results indicate that evergreen broa dleaf forest cover scenarios can significantly alter evapotranspiration and streamflow in the studied basin.The annual evapotranspiration increases 5.6% and the annual depth of streamflow decreases 6.7%;the annual depth of streamflow under grass cover scenarios.The modeling of streamflows spacial distribu tion with LSX-HMS model shows that there is a great difference under various scenarios.This research provides a basis for developing, utilizing, allocating and managing water and soil resources in the Huaihe river basin.