基于SWAT与新安江模型的闽江建阳流域径流模拟研究

Runoff Simulation in Jianyang Watershed of Minjiang River Based on SWAT and Xin’anjiang Model

采用SWAT模型对闽江建阳流域的日径流过程进行模拟计算,利用研究区1993年~1997年的实测流量数据进行模型参数率定,1998年~2000年的实测流量数据进行模型检验,并与三水源新安江模型的模拟结果进行对比,采用纳什效率系数NS、相对误差RE和决定性系数R^(2)作为模型模拟精度的评价指标。研究结果表明,两个模型在建阳流域日径流模拟中都具有较好的适用性,且均能很好地用于该流域的径流预测与防洪规划。进一步分析建阳流域降雨和径流空间分布与变化特征的结果表明,该流域多年平均降雨量从西北向东南递减,径流空间分布与降雨空间分布相似,差异较明显;研究区总体径流呈增加趋势,但径流深的空间分布差异性呈减小趋势。

The SWAT model is used to simulate and calculate the daily runoff process in Jianyang Watershed of Minjiang River.The measured discharge data from 1993 to 1997 in the study area are used to calibrate SWAT model parameters,and the measured discharge data from 1998 to 2000 are used to test SWAT model parameters.The daily runoff simulation results of the SWAT model are compared with that of the three-source Xin’anjiang model,and the Nash-Sutcliffe efficiency coefficient NS,the relative error RE and the deterministic coefficient R^(2)are used as the evaluation indexes of model simulation accuracy.The results show that both Xin’anjiang model and SWAT model have good applicability in daily runoff simulation of Jianyang Watershed and can be used for runoff prediction and flood control planning.The spatial distribution and variation characteristics of rainfall and runoff in Jianyang Watershed are further analyzed by using SWAT model,and the results show that,(a)the average annual rainfall in the watershed decreases from northwest to southeast,the spatial distribution of runoff in the watershed is similar to that of rainfall,and the spatial distribution difference is obvious;and(b)the overall runoff depth in the study area presents an increasing trend,but the spatial distribution difference of runoff depth presents a decreasing trend.