Runoff simulation in the upper warta catchment during 1992 and 1993

Abstract

The land-surface parametenzation model SEWAB (Surface Energy and Water Balance) has been developed to provide the lower boundary condition for atmospheric models. It solves the coupled system of the Surface Energy and Water Balance equations considering partly vegetated surfaces. Within the soil column the vertical diffusion equation for soil temperature and soil moisture are solved semi-implicitely at a variable number of layers. SEWAB is a parameterization to be used to link the atmospheric and hydrological models e.g. in the Baltic Sea Experiment (BALTEX), a continental scale experiment under the Global Energy and Water Cycle Experiment (GEWEX). The catchment under consideration is first overlaid by a grid net, e.g. of the atmospheric model, then SEWAB is applied to each grid box. Runoff calculated from each grid box is the input to a hydrological model describing the horizontal transport to and within the river network on a daily bases. Calculated streamflow can be compared to measurements at gauging stations, validating not only the model results from the atmospheric model but also providing daily river runoff to ocean models. In this paper the model and methods are briefly introduced. Results are shown for the upper Warta catchment using measured meteorological data to force the model.