平原河网区最优化汇流单位线法及其应用

Optimization Method of Concentration Unit Hydrograph on Plain River Network Region and Its Application

针对利用现有单位线方法模拟平原河网区汇流特性难以得到较好结果的问题,在传统单位线方法的基础上,根据平原河网区的实际特点,基于河网多边形和河道水位资料,提出了适用于平原区的单位线模型。通过对典型区域的平原区单位线进行率定和缩放,获得了适用于平原河网的平原区单位线,并利用太湖流域1998年和2000年的水文资料进行建模和验证。结果表明,平原河网区最优化汇流单位线法能基本消除太湖流域的洪峰(水位)滞时误差。

It is difficult to simulate the actual hydrologic process on plain area by traditional unit hydrograph method. This paper analyzes the characteristics of river network on the plain area, and puts forward the plain unit hydrograph method （PUH） to improve the traditional method. The new method is based on the river network polygons and water level, which makes it applicable to the plains. The plain unit hydrograph on the basin comes from the process of calibra- tion and scaling the ones of small plain typical regions. In the paper, a demo model on Taihu Basin is shown. The data of 1998 and 2000 are used for calibration and validation. The results prove that by optimization method, the plain unit hy- drograph based on river network polygons could achieve better simulation accuracy on Taihu Basin, reducing the time lag of flood peak calculated.