流域数字水文模型研究

A Study on Digital Hydrological Modeling

探讨了数字水文模型的基本内涵和基本框架 ,首先利用数字高程数据自动提取流域水系 ,构建数字高程流域水系模型 ,主要包括数字高程模型中凹陷区域的识别和处理、平坦部位水流流向设定、子流域集水单元勾划、河网生成、河网与子流域编码及河网结构拓扑关系的建立 ;然后在每一集水单元上建立数字产流模型 ,再根据河网结构拓扑关系建立数字河网汇流模型 ,从而形成数字水文模型 .通过淮河流域能量与水分循环试验强化观测资料的检验 。

A discussion is made on connotation and framework of the digital approach to catchment hydrological modeling.Meanwhile,a brief review is made on automated extraction of drainage network from grid digital elevation model (DEM).The Digital Elevation Drainage Network Model (DEDNM),developed by Martz and Garbrecht,is introduced,including model structure and computational procedure such as identification and treatment of depression or sink in DEM,raster based flow vector determination containing flat areas,sub watershed delineation,drainage network generation,numbering of network and subcatchment,and production of topological relation of river network structure.Then,the DEDNM is applied to the Shiguanhe River Basin of an area of 5930 km 2,the intensified observation field for the HUBEX/GAME.The result shows that the drainage system generated by the DEDNM is acceptable as compared with that on 1∶100?000 topography map.That provides a solid foundation for development of digital hydrological model.Digital rainfall runoff model can be established by use of the principle of Xin′anjiang Model over each subcatchment produced and numbered by the DEDNM.Finally,runoff is routed from each subcatchment to the catchment outlet by the digital network routing model on the basis of topological relation of river network structure produced by the DEDNM.The digital hydrological model works very well when used to simulate hourly and daily flood hydrograph in the Shiguanhe River Basin during the plum rainy period of 1998.