基于SWAT模型的内蒙古闪电河流域径流模拟研究

以内蒙古闪电河流域为研究对象,采用分布式水文模型SWAT对闪电河流域水文过程进行模拟,模型采用1962～1975年月径流资料进行参数率定,将1986-2001年作为模型的检验期对模型的适用性进行评估。结果表明:实测与模拟的逐月流量总体较为接近,率定期和验证期的Nash-Sutcliffe效率系数均大于0.60,实测与模拟的月流量之间的相关系数在0.65以上,率定期的多年平均相对误差小于5%。由于人类活动的影响,验证期的模拟误差相对较大,超过12%。总体来看,SWAT模型参数经多次率定之后,能够较好地模拟干旱半干旱地区的径流过程,在同类地区具有一定的适用性。模拟过程中,对于降水量突然增大的月份,SWAT模型对月径流量的模拟结果往往超过实测值一倍,直接导致整个模拟过程的误差偏大。然而,模拟值与降水量在年内分配上却表现出很好的相关性,降水偏大的月份径流量敏感性大。同时,SWAT模型模拟径流结果受参数影响很大,调整融雪参数值,模拟精度在原有基础上相对提高。

Using SWAT model to simulate the discharge of the river Shandianhe in Inner Mongolia

Taking the Shandianhe River as a case study area,hydrological process of the basin was simulated with a distributed SWAT model.Data series from 1962-1975 were used to calibrate the SWAT model,and periods of 1986-2001 were employed to validate model.Results indicate that the monthly recorded and simulated discharges match well for calibration period and the validation period.Nash-Sutcliffe coefficients,as well as correlation coefficients between recorded and simulated discharge for both calibration period and the validation period are all above 0.60 while relative errors are less then 5%.Partly due to intensive human disturbance in the validation period,relative error of validation period is more than 12%,indicating SWAT model performs well for monthly discharge simulation,and could be applied to the catchments in the arid or semi-arid regions.However,the model performs poor for these months when the precipitation is extremely larger than multi-mean while neighboring month rainfalls are much lower than normal.In general,the seasonal pattern of the simulated discharge is highly in accordance with the recorded.Runoff in flood season is more sensitive to changes in parameters.For Shandianhe river basin,a suitable snow-related parameter could improve accuracy of discharge simulation to some extent.