SWAT模型中集水面积阈值对径流模拟的影响

选择滁河汊河集水文站上游流域为研究区，应用适度指数法获取最优集水面积阈值，并在此基础上设定阈值序列。应用SWAT分布式水文模型，进行不同集水面积阈值条件下的流域径流模拟，进一步分析集水面积阈值对流域径流模拟结果的影响。研究结果表明：适度指数法能够满足径流模拟中集水面积阈值的确定；径流量对集水面积阈值的变化不敏感，最大相对偏差不超过6％，但仍存在适用范围的上下限。

Influence of different catchment area threshold On SWAT runoff simulation

It takes the area which is within upper watershed of Chaheji hydrological network in Chuzhou as the study area. The fitness index methods are used for the optimal catchment area threshold. A threshold Is sequence is set up based on the optimal threshold. By using SWAT distributed hydrological model, the runoff of the study area is simulated under different catchment area threshold. The results show that the fitness index methods can satisfy the calibration of the catchment area threshold for runoff simulated. The runoff yield hardly changes with the variation of catchment area threshold, with the maximal relative deviation less than 6%, but the threshold should be within the scope of application.