不同时间步长对淮河上游次洪产沙模拟的影响

Influence of Different Time Steps on the Simulation of Second Flood Sediment Yield in Upper Reaches of the Huaihe River

为分析时间步长对次洪产沙模拟的影响,以淮河上游大坡岭水文站以上流域为研究区域,选取2001～2010年具有代表性的10场次洪降雨、径流和含沙量等资料,分别以0.5、1h为时间步长,利用泥沙负荷模型模拟计算了10场次洪产沙过程。结果表明,泥沙负荷模型的9个参数中参数b5、b6、b8随时间步长的变化而变化,且步长变化对b5、b8的影响最大;以沙峰相对误差、确定性系数和峰现时差三个指标综合衡量,时间步长为0.5h的模拟精度总体上高于时间步长为1h的模拟精度。研究成果可为淮河流域及湿润半湿润地区土壤侵蚀模拟提供参考。

In order to study the impact of the time step on the flood event sediment simulation,The Dapoling hydrological station in the upper reaches of the Huaihe River was selected as the case study area.Selected ten typical second flood data in 2001-2010 including rainfall,runoff and sediment concentration,with 0.5hand 1has time step,sediment load model was used to simulate the process of second flood sediment yield.The results show that three parameters（b5,b6 and b8）of the total nine parameters in sediment load model changes over time step,and the impact of time step on b5 and b8is obvious.Taking the sand peak relative error,deterministic coefficient and peak current difference as evaluation indexes,the simulation accuracy with 0.5htime step is better than that of 1htime step.The research results have reference value for soil erosion simulation in the Huaihe River Basin and the humid and semi humid regions.