基于非线性系统理论的分布式水文模型
Distributed hydrological modeling based on nonlinear system approach
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摘要: 提出了一种基于水文系统理论的分布式水文模拟方法,它将集总的水文非线性系统模型通过GIS平台,结合单元水文模拟,拓展到分布式流域水文模拟。它既具有分布式水文概念性模拟的特征,同时又具有水文系统分析适应能力强的优点。实例分析表明:在黄河板桥流域,通过考虑时变增益因子G的空间变异性,该模型吸纳了局部高强度降水信息,对分布式空间降水输入能够产生积极的响应,获得了比集总模型更好的峰值模拟效果;在华北潮白河流域,通过分析不同森林覆盖率下的G值变化曲线,初步揭示了潮白河流域土地利用变化的水文响应趋势,即在相同的土壤湿度条件下,随着森林覆盖率的增加,G值呈减小趋势,地表产流能力降低。Abstract: The distributed rainfall-runoff model has the advantage of being physically-based. However,this model is difficult to apply because of the demands on the input data,much of which is not directly measurable,and computational time. This fact has led to the development of simplified distributed models,such as the Distributed Time Variant Gain Model(DTVGM), by a combination of physical or conceptual processes with a nonlinear system approach. In the Banqiao Basin of Yellow River, considering the spatial variation of precipitation,the DTVGM makes positive response to the distributed input data and obtains higher precision in streamflow simulation than that of the lumped model. In Chaobaihe River basin of North China,by analyzing the variation of the time variant factor G for different land use types,the response trend of runoff to the land use and cover change is preliminarily showed:in case of the same soil moisture condition,the value of G decreases,which means that the surface runoff generation ability decreases with the increase of the forest cover.