Metro-hydrological, biophysical data integration for water circulation and water resource simulation from watershed to basin scales in a distributed schemes

摘要

Integration of spatial metero_hydrological, biophysical data to drive terrestrial water circulation models requires not only that the data layers themselves be spatially compatible, but also that they adequately resolve landscape attributes that the models require. Two study sites, one located at the semi_arid region of Heihe River Basin in northwestern China and another in humid area of Yangtze River Basin in Hanjiang plain, have been selected to simulate water dynamics and soil erosion process at watershed (several hundreds km2)to basin (4,000２km) scales by integrating soils, topographic, vegetation, and meteorological data with varying data resolutions and levels of topographic aggregation. Preliminary simulations indicate that spatial correlation of input variables with synoptic weather patterns is critical in determining dynamic processes such as hydrologic outflow and evapotranspiration, yet is not always possible across large regions or heterogeneous terrain. Simulation of hydrological processes at watershed to basin scales typically requires both intensive and extensive biophysical and meteorological parameterization of the earthu27s surface and atmosphere. Unfortunately, critical processes governing the interaction between terrain surface-vegetation-atmosphere at spatial scales from local to regional, and at temporal scales that range from instantaneous to seasonal, are not easily incorporated into such models that require multiple data of fixed spatial or temporal resolution as input at present. In order for the distributed models to adequately describe or predict physical processes such as streamflow dynamics, input data resolution must be compatible not only with the scale of actual hydrological functioning, but also with the resolution at which interpretation of results is critical. In this paper, the general objectives of the research undertaken in Nanjing University within a large multidisciplinary project named simply as “973”， founded by Ministry of Science & Technology, China were reviewed, the current progress and the problems existed for further efforts were discussed.