The spatial heterogeneities of hydrological parameters in watersheds with limited extents should be accounted by the
distributed hydrological model. Dongting Lake is selected as the study area and divided into 19759 hydrological
response units based on DEM according to the concept of drainage density. Each unit has one land-use type and one soil
type. The hydrological response units are utilized as the minimum units in simulations of hydrological processes and a
parameter database of the distributed hydrological model is designed under the support of GIS. The parameters are
managed with layers in the database. The structure of the database is helpful for organizing and updating the parameters.