基于流域基本单元的分布式流域汇流计算方法

Calculation Method of Catchment Distributed Concentration Model Based on Basic Unit

结合现行离散化方法的优缺点,引入流域基本单元的概念,在DEM平台上利用Arcview软件将流域离散化为基本单元,计算流域地貌特征值,构建基本单元—河网型分布式流域水文模型。推导出V形和马蹄形基本单元的面积—时间曲线,用以计算坡面汇流;对于河网汇流则运用Muskingum法计算,其优势在于可充分考虑水流汇集的物理概念和下垫面因子分布不均对流域汇流的影响。以星丰流域和沿渡河流域为对象进行水文模拟应用研究,结果表明,该模型具有良好的适用性。

The concept of watershed basic unit is introduced by analyzing the characteristics of current discretization methods. Basic unit-river network distributed hydrological model is established through diseretizing watershed into basic units with Arcview software on the DEM platform and calculating the eigenvalue of watershed landform. Area-time curves of V-shaped unit and hoof-shaped unit are deduced for calculating over land flow concentration. The river network concen- tration flow is calculated by Muskingum method. The advantage of this model is that not only the physical concept of wa- ter concentration but also the impact on concentration flow by uneven distribution of underlying surface factors are consid- ered. This model is applied to research of hydrological simulation of Xingfeng watershed and Yanduhe watershed. The simulation results indicate that this model has good applicability.