苕溪流域控制断面河网概化水质订正方法

大型复杂河网河道众多,水系复杂,加上模拟方法存在理论缺陷及概化河道产生误差,在模型运算中对规模较小的河道进行概化处理会导致水质模拟精度降低。为提高水质模拟精度,以杭嘉湖平原苕溪流域控制断面为例,通过引入陆域宽度概念,对河道概化前后流量及水质浓度进行修订。结果表明,苕溪流域控制断面COD、氨氮订正系数为0.96~1.11,订正后COD、氨氮浓度平均误差分别减小了3.58%、5.36%,水质精度有所提高,可见该方法在模型应用中具有较好的适用性。

Revised Method of Water Quality at the Controlled Section in Tiaoxi Basin

The large complex river network has many branches and complicated water system. The smaller size channels were generalized in model operation. On account of the simulation method defects and generalized channel errors, the water quality simulation precision is low. In order to improve simulation accuracy of water quality, taking Tiaoxi basin in Hangjiahu plain for an example, it revised the flow and concentration of water quality before and after generalized river channel. The results show that correction coefficient of COD and NH3-N is 0.96-1.11 in controlled section of Tiaoxi basin; the average error of COD and NH3-N concentration are reduced 3.58% and 5.36% after rectifying; the accuracy of water quality is improved. Therefore, the correction method has better applicability in model application.