Water Quality Model of the Urban River with Multi-Drainage Outlet Based on Simulink A Case Study of Segment between Changxing Bridge to Shawangdu of Wei River

摘要

本文以渭河干流常兴桥至沙王渡断面为例,利用Matlab2010中的Simulink组件构建了在多排污口影响下的城市河流水质响应模型.根据渭河的实际调研与监测的结果,在模型中考虑了在水文变化条件下模型中的降解系数、河宽、底泥释放等重要参数的变化.模型重点反映了污染物从多排口(或支流)汇入渭河干流的过程、COD的扩散降解过程以及底泥的负荷贡献.结果表明:该模型的模拟效果好,水质模拟相对误差为0％～35％,负荷模拟相对误差为0％～36％;关中段底泥的负荷贡献与外源汇入量相当,且基本上集中在汛期；渭河关中段的年负荷超过饱和,且由于水量分配不均,造成超标现象普遍,除河段1,河段5至河段7以外尚可满足水体功能,其余各个河段的超标率在31％～99％.%Based on Simulink in Matlab 2010,the water quality model of an urban river with multi-drainage outlet is built.The key parameters such as degradation coefficient,segment width,COD from sediment,etc.can be dynamically obtained with the varying input flow.The model includes the process of pollutant discharge from drain outlets,COD degradation and diffusion,the influence of the sediment.It is showed that the errors of water quality simulation are between 0％ and 36％ and errors of the load simulation are between 0％ and 35％; The load from sediment is nearly the same as from the drain outlets; The annual COD load has exceed the limitation,which cause the water quality commonly out-limits with water shortage.The exceeding rates of the segnents are between 31％ and 99％.