基于地形指数的混合产流关键土壤变量空间离散方法及其空间尺度效应

Spatial Discretization of the Key Soil Variables in Mixed Runoff Generation Based on the Topographic Index and Its Spatial-Scale Effect

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摘要下垫面作为产流过程发生的载体,其空间异质性表达会极大的制约流域水文模型的模拟效果。河北雨洪模型作为我国北方半湿润半干旱地区混合产流的代表性流域水文模型,对关键土壤变量的处理方法(即以土壤蓄水容量和下渗能力分布曲线概化流域分布的空间异质性),使其难以发展为基于网格的概念性分布式模型。研究基于TOPMODEL中的地形指数概念,提出了一种实现土壤蓄水容量与下渗能力在空间网格上的离散方法,并进一步探讨在中小流域不同空间网格尺度下的洪水模拟表现。结果表明,采用该混合产流结构可以较好的再现历史典型洪水,但随着空间分辨率的降低,关键土壤变量的空间离散效果及最终的径流模拟结果可能会存在失真情况,需要依据流域面积进一步确定分布式模型的最佳空间尺度。研究为概念性水文模型产流结构移植以及混合产流关键土壤变量的空间合理表达提供了新的思路。 The underlying surface is the carrier of the runoff generation process,and its spatial heterogeneity expression can greatly restrict the final simulation effect of the hydrological model.As a representative hydrological model for mixed runoff generation in the semi-arid and semi-humid regions of northern China,the Hebei rainfall-runoff model uses two cumulative distribution curves to describe the spatial heterogeneities of the soil infiltration capacity and the soil water storage capacity.That brings a great challenge in transferring it into a grid-based conceptually distributed model.Based on the concept of the topographic index in TOPMODEL,this study proposed a methodology to spatially discretize the soil water storage capacity and the infiltration capacity on the grid,and further explored its application for flood simulation in small and medium-scale catchments with the grid scales of 1 km×1 km,3 km×3 km,9 km×9 km.The results show that the mixed runoff generation structure can realistically reproduce the typical historical flood processes.However,as the spatial resolution decreases,the spatial discretization effect of the key soil variables may be distorted and the final runoff simulation results would get worse.The optimal grid scale of the distributed model needs to be further determined based on the catchment area.The study provides a new methodology for the transplantation of the runoff structure in the conceptual hydrological model and for the exploration of the reasonable spatial expression of the key soil variables in the mixed runoff generation.

作者王维刘佳王洋胡春歧李传哲 WANG Wei;LIU Jia;WANG Yang;HU Chunqi;LI Chuanzhe(State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing 100038,China;State Key Laboratory of Hydrology Water Resource and Hydraulic Engineering,Hohai University,Nanjing 210098,China;Swanson School of Engineering,University of Pittsburgh,Pittsburgh 152164,U.S.A;Hebei Hydrological Survey and Research Center,Shijiazhuang 050031,China)

机构地区中国水利水电科学研究院流域水循环模拟与调控国家重点实验室河海大学水文水资源与水利工程科学国家重点实验室匹兹堡大学斯旺森工程学院河北省水文勘测研究中心

出处《水文》 CSCD 北大核心 2021年第4期13-20,共8页 Journal of China Hydrology

基金国家重点研发计划资助项目(2017YFC1502405) 国家自然科学基金资助项目(51822906) 国家水体污染控制与治理专项(2018ZX07110001)。

关键词混合产流空间离散空间尺度效应河北雨洪模型概念性分布式地形指数土壤下渗能力土壤蓄水容量 mixed runoff generation spatial discrete spacial scale effect Hebei rainfall-runoff model conceptual distributed hydrological model topographic index soil infiltration capacity soil water storage capacity