基于DEM的清水河分布式水文模型

Distributed hydrological model based on DEM in Qingshui River Basin

对于以冰雪融水和雨水混合补给为主的西北山区流域,需要结合山区特点建立分布式水文模型。通过取塔里木河流域中的清水河水系为研究区域,采用300 m×300 m DEM数据进行流域河网水系提取,同时用DEM数据对参数进行分布式异化,建立冰雪融水与降雨相结合的分布式水文模型。分析模拟结果表明:夏季模拟径流主峰值与实测径流值较为接近,而冬春季节两者之间的差别较大,反映了西北山区流域冰雪融水和雨水混合补给为主的特点;进而开拓塔里木河区域应用该类模型的可行性。

Hydrological model is always one of the important means for deeply probing into the laws of water cycle and water resources evolvement. Nowadays the techniques of hydrological model trend to be integrated with GIS in order to utilize the functions of GIS data management, space analysis, and visualization; however the DEM is the basic data of GIS. With the distributed hydrological model based on DEM becoming the hotspot in hydrology, it is necessary to develop some kinds of distributed hydrological model adapting to the character of northwest mountains where snowmeh water and precipitation are the main replenishment of runoff. The papers on distributed hydrological model in Tarim basin, the biggest inland river in China, are seldom seen. In this paper, the author selects the water system of Qingshui River in the Tarim basin as the study area, adopts mechanism of mixed runoff-yield, construets runoff-producing model by the grid cell; then sets the parameters for basin flow concentration based on the path of runoff, and adopts isochrones to develop the distributed hydrological model combining snowmeh with precipitation after distributing parameters based on the data of 300 m × 300 m taking effect of hysteresis into account. The results show that the simulated peak value is similar to that of observed in summer, however they are different in spring and winter, which indicates the character of northwest mountains that have the main replenishment of snowmeh and precipitation for runoff again. Therefore, we can confirm that the model is feasible to the Tarim River basin of to some degree.