广东省综合单位线法的改进

Improvement Research of the Guangdong Synthesis Unit Hydrograph Method

为了减小广东省综合单位线法实际运用中的误差,将计算流域进行地貌分类,引入径流系数,对鱼塘以外地块的毛雨量进行折减得出设计净雨量,对鱼塘通过累加的毛雨值扣除一定的蓄水深度得出设计净雨值,再由广东省综合单位线法提供的设计雨型计算得出流量过程线.此方法改进了初损的计算,较容易操作而又切合实际,可提高广东省综合单位线法的计算精度.

The synthesis unit hydrograph method that has been issued by Water Conservancy and Electric Power Department of Guangdong Province,and widely used in Guangdong hydrologic computation and flood forecasting is still an important tool for the computation of flow concentration.The runoff generation analysis based on such method uses initial loss method without deduction from initial losses in order to simplify the calculation,which,however,results in big error in the application in the Delta of the Pearl River,where fish ponds exist in great numbers.In this paper,the author is trying to introduce some method and use the designing rainfall model of the Guangdong synthesis unit hydrograph method to compute the basin flow concentration curve.This method,while calculating the land without fish ponds,sorts the drainage area by landform and introduces the runoff coefficient to compute overland flow concentration through discounting area rainfall.Whereas calculating the fish ponds,it computes runoff yield through deducting the storage capacity of ponds.Such method is simple and practical to improve the initial losses calculation and increase the accuracy of the Guangdong synthesis unit hydrograph method.