淮河流域不合理的土地利用是导致水土流失的重要因素之一，探究土地利用变化下的水文响应规律是开展水土保持工作的重要前提。以淮河王家坝水文站以上流域为研究区域构建SWAT模型，并验证模型的适用性；对研究区耕地进行适宜性评价，结合2000年土地利用现状构造最佳土地利用情景；利用验证好的SWAT模型分析最佳土地利用情景、生态保护情景、土地利用现状情景的水文响应。结果表明，相比2000年土地利用，生态保护情景水文响应变幅较小，而最佳土地利用情景下41.29%的耕地转化为林地，年、月均地表径流和年、月均泥沙量减小，年、月均地下径流增加，年、月均蒸发量变化不大。说明最佳土地利用状态有助于提高研究区域涵养水源、保持水土的能力，且在汛期效果较为明显。

In the Huaihe watershed, unreasonable land use is one of the important factors that lead to soil erosion. It’s the important premise to explore the land use change under the hydrological response in terms of carrying out the work of soil and water conservation. In this study, the SWAT (Soil and Water Assessment Tool) model was established with the upper Huaihe River basin upstream of the WangJiaBa hydrologic controlling station as the study area. Firstly, the applicability of the model was verified. Then the optimal land use scenario was constructed by farmland suitability evaluation. Finally, the hydrological responses to the optimal land use scenario, ecological protection situation and the land use in 2000 were analyzed using the SWAT model. The results showed that hydrological response changes of ecological protection situation were very small. Based on the optimal land use scenario of land suitability evaluation, 41.29% of the farmland was turned into forest land. As a result, compared with the land use in 2000, the annual surface runoff and sediment yield were decreased, ground water was increased. Monthly surface runoff and sediment yield were decreased, and monthly ground water was increased. However annual and monthly evaporation changed slightly. The study revealed that in the condition of optimal land use, the ability of soil and water conservation was stronger, and it was more obvious in flood season.

水利部“十二五”公益性行业专项经费项目（201301066）；国家自然科学基金项目（51409152）