基于SWAT模型的TRMM降水数据径流模拟适宜性评价

Evaluation of Runoff Simulation Using TRMM Precipitation Data Based on SWAT Model

以辉发河流域为研究区,采用SWAT分布式水文模型,以实测降水数据和TRMM降水产品作为模型输入,在月尺度和日尺度上构建了四种径流模拟情景,并利用SUFI_2算法分析了不同降水输入和时间尺度下模型的参数敏感性、参数不确定性和径流模拟结果。结果表明:(1)TRMM降水产品的误差会改变参数的敏感性排序,尤其是在日尺度上;(2)4种模拟情景P因子的范围为0.58~0.9,R因子的范围为0.47~1.58,模型拟合精度较好。月尺度上TRMM数据的估算误差较小,其更高的空间分辨率可使径流模拟不确定性得到明显改进,而随着时间尺度的变化,TRMM数据在日尺度上的误差增大会导致日径流模拟结果不确定性的增加;(3)在月尺度和日尺度上,采用TRMM数据降水输入模拟径流,其NS和R2系数均达到较好水平,实测降水模拟结果略优于TRMM数据。研究表明,在辉发河流域,TRMM降水产品在径流模拟方面表现出较好的适宜性,是一种较为可靠的降水数据源。

Four runoff simulation scenarios were constructed in Huifa river basin using the distributed hydrological model SWAT at monthly and daily scales with observed precipitation data and TRMM precipitation products as the input of model.Then,parameter sensitivity,parameter uncertainty and runoff simulation were analyzed under different precipitation inputs and time scale using SUFI_2algorithm.The results showed that:(1)the error of TRMM precipitation products could change the parameters of sensitivity ranking,especially on the daily scale;(2)P-factor of four simulated scenarios was in the range of 0.58~0.9and R-factor in the range of 0.47~1.58,which indicated that the model had the better fitting precision;TRMM data could make the runoff simulation uncertainty significantly improved due to its small estimate error at month scale and higher spatial resolution;with the change of time scale,increasing TRMM data error at daily scale could lead to the enlarged uncertainty of daily runoff simulation;(3)on the monthly and daily scales,both NS and R2 of runoff simulation using the TRMM data reached to a good level,and the result simulated by using measured rainfall was slightly better than that of the TRMM data.The results suggested that the TRMM precipitation products were a reliable source of precipitation data for runoff simulation in Huifa River Basin.