应用官司河分布式水文模型模拟流域降雨—径流过程

SIMULATING RAINFALL-RUNOFF PROCESSES BY GSH MODEL, A PHYSICALLY-BASED DISTRIBUTED HYDROLOGICAL MODEL

由于地理要素 (地形、气候、土壤、植被等 )的空间异质性 ,森林的生态服务功能 ,尤其是涵养水源和保持水土的功能 ,也存在着空间分异。本文根据森林水文过程和森林水文生态功能的形成机理 ,建立了通用性较强的官司河分布式水文模型。官司河模型根据流域内部地理要素的空间异质性把流域分成一系列的单元和作用层 ,以单元和作用层为基本单位 ,连续计算每个单元和作用层的水文过程和水文要素变化 ,包括降雨输入、冠层截留、枯落物层吸水、入渗、蒸散、壤中流、地表径流等 ,进而得到流域水文的时空变化。用此模型模拟了四川绵阳官司河流域的降雨—径流过程 ,计算结果与观测结果基本吻合。

The ecological services of forests, especially water and soil conservation, vary spatially due to the spatial heterogeneity of physical geographical elements, such as topography, soil, vegetation, climate. Guansi River hydrological (GSH)model, a general physically based distributed hydrological model on watershed level, was established in this paper. In GSH model, the watershed was distinguished into different regular cells. Each cell was supposed to be homogeneous in canopy structure, litter composition and structure, land surface features, and soil characteristics which were defined as different layers in the model. GSH model calculated water movements through the canopy and soil layers in every cell of the watershed and simulated water flow among neighbor cells, including rainfall, canopy interception, absorption of litter layer, infiltration, evapotranspiration, subsurface runoff and surface runoff. It can be obtained from GSH model the change of water distribution in the watershed when using the change of physical elements in both spatial and temporal dimensions as input of the model. By using GSH model, rainfall runoff processes were simulated in Guansi River watershed, Sichuan Province, Southwest China. The simulated result agreed well with the measured data.