基于DEM的分布式水文模型在大尺度流域应用研究

本文选取空间大尺度黄河河源区流域为研究对象,利用分布式水文模型进行径流量模拟,采用1976～1985年唐乃亥水文站逐年、月实测径流资料进行参数率定,确定模型的基本参数,得到了较好的模拟效果。模拟结果表明气候变化是引起黄河河源区径流变化的主要原因。在80～90年代的20年间,黄河河源区由气候变化引起径流减少62.11亿m3,占径流变化总量的108.72%,由土地覆被变化引起径流增加5.73亿m3,增加量占径流变化总量的10.03%。

An Application Study of DEM Based Distributed Hydrological Model on Macroscale Watershed

The paper selected the macro-scale areas of the source region of the Yellow River as an object and carried out discharge simulation with the distributed hydrological model,the SWAT model.Based on the analysis and process of DEM data,such as flow direction,a watershed borderline,a river network and sub-basins by automatically becoming,rivers,codes and areas of sub-basins,structure and topology constraint of the river network were gained with a format of grid cells.Annually and monthly measured runoff data of Tangnaihai hydrologic station from 1976～1985 were used to calibrate the simulation parameters and determine some basic parameters of the model.The simulation results are satisfactory and show that climate change is the main reason for discharge change of the source regions of the Yellow River.In twenty years of the 1980’s and the 1990’s,the discharge decrease due to climate change is 62.11×108m 3/s,which accounts for 108.72% of total discharge change,and the discharge increase due to land-cover change is 5.73×108m 3/s ,which accounts for 10.03% of that with grid cell.