The Application Of TOPMODEL In Runoff Simulation With Support Of GIS

Hydrological models are widely used in the development and utilization of water resources, protection of water resources, flood prevention and disaster reduction, reservoir design and management, road planning, urban planning, pollution assessment, the hydrological processes to land-use change, and many other aspects of a wide range of applications. Some hot contemporary research, such as the hydrological processes in response to global climate change, ecological environment required quantity estimates, water and renewable sources of hydrological models to assess all need the support of hydrological models. GIS is a technology systems which makes use of systems engineering and information science theory, to scientific manage and comprehensive analysis of the content of geographic data space to provide required information for the planning, management, decision-making and research.This article discusses the applications of semi-distributed hydrological model TOPMODEL, supported with GIS, in the basin runoff simulation. Firstly, the author compared the currently available distributed hydrological models and chose the TOPMODEL for the study which has simple structure, low flow parameters. And six kinds current methods of hydrological models coupled with GIS were also discussed. Secondly, the physical mechanisms, basic equation and assumptions of TOPMODEL are analyzed; the terrain index, one of important parameters of TOPMODEL was explained in detail; the application of DEM in TOPMODEL, and the methods to acquire DEM based on GIS are discussed. The process and methods to extract parameters of terrain index based on hydrological and analysis functions of GIS were also discussed. Thirdly, a detailed discussion of the coupling of the irrigation areas system based on ArcEngine components and TOPMODEL models are made. The COMGIS techniques, the characteristics, functions and composition of ArcEngine components, the development of the system interface, the packaging models methods, the mode of coupling of hydrological models and GIS system based on COM in VC#.NET are expatiated. At last, the data organizations methods of TOPMODEL and irrigation areas and the structures of the Shulehe irrigation areas GIS system were discussed, and the calculations of models were expressed with GIS.