常用的概念性水文模型 ,能够很好地模拟水文时间变化过程 ,但没有考虑水文变量和水文参数的空间变化与空间不均匀性。随着空间数据的获取手段的增多以及空间离散技术的发展 ,考虑水文参数和水文变量空间变化的分布式水文模型得到了极大的发展。本文详细介绍了分布式流域水文模型中用到的几种不同计算域离散方法 ,并讨论了河道汇流模型中常用到的有结构网格和无结构离散网格。地理信息系统技术对计算域离散有辅助作用 ,其有利于无结构离散网格的自动生成和交互修改 ,并可结合遥感技术 ,使水文模型能获取精确的空间分布的水文参数和水文变量。

In the lumped hydrological model the temporal hydrological process can be simulated very well with no concern to the spatial distribution and spatial variation of the hydrological variable and hydrological parameters. With the increase of the spatial data and the development of spatial discretion technology, the distributed hydrological model, in which the spatial distribution is concerned, is the research focus in the recent years. In this paper the discretion method, which is used to discrete the computational domain of the distributed hydrological model and flood routing model, is discussed in detail. In the distributed rainfall runoff models there are several computational domain discretion methods, such as representative elemental areas, or REA; hydrological response unit, or HRU; grouped response unit, or GRU; and aggregated simulation areas, or ASA. In the runoff routing model, the computational domain can be discreted into structured mesh and unstructured mesh. The structured mesh can be regular mesh and irregular mesh. In addition, we also elucidate the role of Geographical Information System technology and Remote Sensing in the hydrological model and its computational domain discretion. GIS technology can be used to generate and adjust the irregular and unstructured mesh for the computational domain. In addition, RS can provide the information of relief map and landuse map. Based on the GIS and RS, some necessary hydrological parameters can be derived from the relief map and landuse map.