适合沼泽湿地地区的分布式次降雨径流模型

A suitable distributed hydrological model for a single rainfall-runoff event in the marsh wetland area

根据流域降雨径流的基本过程,在充分考虑了流域下垫面水文要素和各种参数的空间异质性的基础上,建立了一个网格型的分布式次降雨径流水文模型.模型基于DEM将流域离散为栅格计算单元,将整个流域降雨径流过程分为产流和汇流两大部分.产流采用考虑地表覆被类型和土壤类型的SCS模型;汇流根据水流特性分别采用运动波方程和Muskingum-Cunge法基于分级汇流的思想进行汇流演算.模型结构简单、参数较少,大多数参数可利用DEM、土地利用类型图直接获取,少数敏感参数通过率定确定.应用研究区内的实测数据对模型进行检验,结果表明:确定性系数都在0.8以上,洪量和洪峰的相对误差基本在10%以内,峰现时间的绝对误差不超过2小时,其结果令人满意.

According to the basic process of rainfall-runoff,this study has established a grid typedistributed hydrological model for a single rainfall-runoff event in full consideration of the spatial heterogeneity of watershed underlying surfacehydrological factors and various parameters.This model discretizes watershed into grid unit based on the DEM and divides the rainfall-runoff process into two parts,runoff generation and confluence.The runoff generation is calculated by SCS Model which takes the vegetation types and soil types into consideration.According to the the characteristic of flow,the confluence is calculated respectively by the kinematic wave equation and the MuskingumCunge methodbased on the idea ofhierarchical routing convergence.The model is simple in structure and few input parameters that most parameters can be obtained directly by DEM and land use map and a few sensitive parameters can be determined by calibration.This model is inspected by the observed data in the study area,the result shows that the deterministic coefficient is above 0.8,the relative error of flood discharge and flood peak basic within 10%and the absolute error of flood time is less than 2 hours.The results are satisfactory.