基于SWAT 模型的区域蒸散发模拟及遥感验证

应用分布式水文模型进行灌区用水效率多尺度评价,可为灌区节水改造提供技术支持,本文运用SCE-UA算法在大兴试验站对分布式水文模型（SWAT）中的夏玉米-冬小麦轮作作物参数进行率定,对SWAT模型中蒸散发相关参数进行了敏感性分析,综合考虑农业灌溉措施和施肥措施,将模型模拟ET与遥感监测值进行对比验证.结果表明,SWAT模型模拟ET与遥感监测ET的确定性系数和Nash效率系数分别达到了0.91和0.90,模拟精度较高；不同的土地利用形式下,蒸散发变化显著,平均误差为6.9％.利用遥感监测ET数据有助于蒸散发的正确模拟,从而有效地提高水文过程的模拟精度.

SWAT-based simulation for regional evapotranspiration and verification by means of remote sensing

The purpose of this paper is to establish a distributed hydrological model for Daxing Irrigation Area which will provide a tool for multi-scale evaluation of water productivity and water-saving in the re- gion. In this paper, Shuffled Complex Evolution （SCE-UA） is used to calibrate the crop parameters of win- ter wheat and summer maize in Soil and Water Assessment Tool （SWAT） in Daxing Station. Based on the actual evapotranspiration （ETa） which was derived from MODIS satellite data from the Institute of Remote Sensing and Application （IRSA） of CAS, the sensitivity of parameters are analyzed using SUFI2, and the most sensitive parameters are selected. After that, by consideration of irrigation and fertilization schedule, the ETa data of long term simulation for different land use is validated. The comparison results of calibra- tion demonstrate that the accuracy of simulation is reasonable and the coefficient of determination R2 and Nash Sutcliffe efficiency reach 0.91 and 0.90 respectively. The relative error for different land use averages approximately 6.9%. The irrigation scheme has a great influence on the simulation of evapotranspiration and the accuracy of regional ET simulation can be greatly improved by using ET from remote sensing monitoring.