子流域划分在时间尺度上对年径流、泥沙及营养物的影响--以漳河上游流域为例

The Effect of Sub-watershed Partitioning on Flow,Sediment and Nutrient Predictions at the Time Scale: a Case Study in the Zhanghe Upstream

以漳河上游流域为研究对象,采用SWAT模型定量化研究子流域划分方案对模型模拟结果的影响,得到以下结论:子流域划分层次对模拟结果的影响存在上限下限两个阈值25、111,子流域划分数量对年均径流量影响较小,对泥沙和营养物影响较大;在枯水年,平水年和丰水年,模拟结果对子流域划分数量的敏感性不一致,丰水年最敏感,枯水年最不敏感;综合考虑模拟精度和模拟效率,漳河上游流域SWAT模拟的最合理子流域划分水平为79个,CSA值为12 411 hm^2,占整个流域面积的0.7%。以上研究成果,对准确模拟该地区的水沙情况奠定一定基础,可为该地区水资源水环境的进一步研究提供技术支撑。

This study investigates how different watershed partitionings affect flows, sediments and nutrients quantitatively by using SWAT model in the upstream of the Zhanghe River. The conclusions are： There are two thresholds for model output responses. The lower threshold is 25.The higher threshold is 111. Simulation results for the sensitivity of the watershed division number are inconsistent in different flow years. Considering simulation precision and efficiency, the most reasonable watershed division level is about 79, the CSA value is 12 411 ha, accounting for 0.7% of the whole area in the upstream of Zhanghe by using SWAT model.The research achievements will lay a foundation for the accurate simulation of actual flows and sediments of the drainage basin and give technological supports to further studies in water resources and environment of the area.