强人类活动平原地区河网提取中的流路强化方法

An intensifying method for extracting drainage networks in a plain with violent human activities

我国北方强人类活动平原地区的水资源问题越来越严峻,基于分布式水文模型的水循环模拟是流域水资源研究的基础,其中基于DEM的河网水系提取是基础环节。平原地区由于沟谷发育不明显,且人工河道和沟渠众多,流域汇流结构支离破碎,常用的河网提取模型往往很难得到正确的结果。本文借助已有的主要干流数字化河网水系,提出了流路强化处理方法,用于对平原地区的DEM进行预处理,经过处理后的DEM输入河网提取模型,可以得到流路正确、且河网密度更精细的河网水系拓扑结构,为分布式水文模型的高精度水文单元划分奠定基础。该方法在强人类活动干扰的典型流域——海河流域进行了应用,对比了流路强化处理前后的河网提取结果,表明该方法是一种方便、快捷、高效的处理方法。

The distributed hydrological model is an essential tool to simulate rain-runoff processses over plains in North China for solving the problem of water shortages. The extraction of drainage networks from digital elevation model （DEM） is a basic work to build the distributed hydrological model in a watershed. Many commonly used methods do not work properly when extracting drainage networks in flat areas with violent human activities. Two reasons for this situation are： the elevation of every DEM cell in this area is nearly the same so it is difficult to determine the flow direction; many man-made canals would disturb the flow direction. This paper puts forward an intensifying method to pre-treat DEM cells of the main stream. By using the proposed method, a topological structure of water system with more detailed and accurate river networks can be derived for dividing the hydrological response units in modeling, The result fits well with the natural stream networks, showing that the proposed method is a convenient, quick and easy method to solve the drainage network extraction problem in flat plains with violent human activities.