SCS模型在黄河中游次洪模拟中的分布式应用

Distributed application of SCS model to flood simulation in middle reaches of Yellow River

针对SCS模型存在的空间描述能力有限等问题,使用概念性源汇(source-to-sink)汇流方法,替换原有的无因次单位线汇流方法,建立基于栅格的分布式SCS模型,并引入2个参数对SCS模型的径流量计算方法进行修正.选择黄河中游八里胡同水文站控制小流域检验了模型.检验结果表明:建立的分布式SCS模型不仅较好地再现了5场典型洪水的径流过程,还能给出分布式径流深等数据供空间分析参考;改进后的参数确定方法使得SCS模型的CN值既能反映区域间类似下垫面组合之间的差异和土壤初始含水量对产流的影响,又无需利用大量的观测资料重新对其进行率定,可供无资料地区的水文模拟参考.

In order to solve the problem that the SCS model has limited capabihty of spatial description of water cycles, a grid-based distributed SCS model was established using the conceptual souree-to-sink routing algorithm instead of the original dimensionless unit hydrograph routing method. The runoff calculation method using the SCS model was modified by introducing two parameters into the model. A small basin controlled by the Balihutong hydrological station in the middle reaches of the Yellow River was selected for model verification. The results show that the established distributed SCS model can not only reproduce the runoff processes of five typical flood events, but can provide the data such as the distributeci runoff depth for spatial analysis. Using the improved method for parameter determination, the CN value in the SCS model can reflect the influences of the differences of underlying surfaces between regions and the initial soil water content on runoff generation, without using a large amount of observed data for re-calibration. This provides references for hydrological simulation in the regions without hydrological data.