降雨输入不确定性对分布式流域水文模拟的影响研究——以武烈河流域为例

降雨输入对分布式流域水文模拟具有重要影响。针对流域降雨资料不完整的情况,以武烈河流域为例,基于反距离加权平均法对雨量站降雨资料进行插补延长,并结合SWAT模型研究了降雨输入不确定性对分布式流域水文模拟的影响。结果表明:不同降雨输入对流域平均降雨量的影响较小,但基于气象站资料的降雨数据在降雨空间差异显著的年份会明显低估面雨量,且在夏季汛期表现更为显著;不同降雨输入对分布式流域水文模拟的影响较大;在雨量站降雨资料不完整的情况下,通过对雨量站降雨数据进行插补延长,相对于直接利用气象站降雨资料,在一定程度上可以提高径流模拟精度,满足降雨资料欠缺流域分布式水文模拟的实际需求。

Effect of Uncertainty in Rainfall Input on Distributed Watershed Hydrological Simulation: A Case Study of Wuliehe River Basin

In a given watershed, the rainfall input has an important impact on distributed hydrological simulation. Thus, there is a real need for more rainfall gauges in order to reflect rainfall variability and its effect on runoff prediction in the watershed scale. However, the rainfall data may be incompleted in some watersheds. Aiming at the problem, this study interpolated the rainfall data with the inverse distance weighted method in the Wuliehe River Basin, and the soil and water assessment tool (SWAT) was applied to analyze the effect of different rainfall input on runoff simulation, and the measured data of rainfall gauges were used for SWAT calibration and validation. The results indicate that different rainfall input have less affect on the average areal rainfall, but the area rainfall would be severely underestimated based on the rainfall data from the weather stations in some years, and largely re - flected during the flood periods. The different rainfall input has significant effects on runoff prediction. Under the situation of rain - fall incompleteness, compared with the directly utility of rainfall data of weather stations within the study area, using the interpolated rainfall data of gauges can increase the accuracy of runoff simulation to some extent, and to fulfill the distributed hydrological simulation in the basins that rainfall data is incompleteness.