一种基于面积-时间关系的单位线分析方法

A Method Deriving Unit Hydrographs Based on Area-Time Relation

为了分析分布或半分布式水文模型计算单元的单位线,提出了一种基于面积-时间关系的单位线分析方法.首先利用数字高程模型(DEM)分析计算面积-时间关系,然后将其转换为流量-时间关系.考虑到流域对径流的调蓄作用,利用线性水库将流量-时间关系转换成单位线.将分析的单位线用于HEC-HMS并在沿渡河流域进行实例应用,结果表明,模拟过程与实测过程拟合较好.提出的方法可用于分析无资料流域的汇流单位线.

A method to derive unit hydrographs for sub-areas of distributed model based on area-time relation was proposed. The area-time histograms derived by means of digital elevation model（DEM） were translated to discharge-time histograms. In order to model the store and delay effect of watersheds on flow, the discharge-time histograms were routed through a linear reservoir and unit hydrographs were obtained. Application of HEC-HMS, in which unit hydrographs were used, in Yandu river watershed was performed. The results show that the simulated flood hydrographs is coincident with the observed ones. The method presented can be used to derive unit hydrographs for ungaged watersheds.