SWAT模型是流域尺度的分布式水文模型，可以在流域尺度上定量评估气候变化和土地利用/覆被变化的水文效应。利用率定的SWAT模型，结合情景分析方法，定量分析了古浪河流域气候变化和土地利用/覆被变化对蒸散发、地表径流等水循环要素的影响。结果表明：降水和气温的改变是引起蒸散发和地表径流变化的重要因素，降水对地表径流的影响更大，气温对蒸散发的影响更大，且均表现出明显的季节性差异；土地利用/覆被变化也会引起蒸散发和地表径流的变化，林地和草地的增加会增加蒸散发和减少地表径流，耕地的增加则会减少蒸散发、增加地表径流，农村居民点或裸地的增加将会显著增加蒸散发和地表径流。

Assessment of climate change and land use/cover changes (LUCC) on hydrological processes is essential for the sustainable development of water resources, especially in the arid/semi-arid regions with limited water supplies. The Soil and Water Assessment Tool (SWAT) was used as a distributed hydrological model to quantify the effects of climate change and LUCC on seasonal variation of surface runoff and evapotranspiration in the Gulang River basin. The results suggested that the variation of precipitation and temperature is the major reason for the variation of evapotranspiration and surface runoff. Surface runoff is more sensitive to precipitation than temperature whereas temperature has a greater impact on evapotranspiration with an obvious seasonal variation. Moreover, LUCC can result in the variation of evapotranspiration and surface runoff as well. The increasing of forest or grass land can increase evapotranspiration but decrease surface runoff, the increasing of agricultural land can decrease evapotranspiration and surface runoff, and the increasing of rural residential area or bare land can increase both evapotranspiration and surface runoff significantly.

北京师范大学“京师学者”特聘教授启动经费和中央高校基本科研业务费专项资金（2009SC-5）