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A. Rezzoug, A. Schumann, H. Zepp, P. Chifflard:
"Field Measurement of soil moisture dynamics and numerical simulation using the kinematic wave approach";
Talk: Third International Conference on Water Resources and Environmetal Research, Dresden; 2002-07-22 - 2002-07-26; in: "International Conference on Water Resources", Schriftenreihe des Instituts für Abfallwirtschaft und Altlasten, 28/1/ Dresden (2002), ISBN: 3-934253-17-2; 191 - 195.

Within a research project dedicated to a model-based description of runoff processes numerical simulations and field measurements of soil moisture dynamics are combined. The general idea to use the kinematic wave approximation theory consists in the description of the plane and profile hillslope curvatures effect on the heterogeneity of the soil moisture distributions and of the related water fluxes within a small catchment. These patterns should be used to develop a simplified model of water fluxes in hillslopes based on kinematic wave theory. Field measurements are used to validate the ability of the hydrological model to represent the soil moisture dynamics and to specify the uncertainties of the results with regard to the applied assumptions, the simplifications made and the parametrization of the model in real world applications.
Within the framework of joint research project about runoff formation of several institutes in Germany financed by the DFG (Deutsche Forschungsgemeinschaft) an experimental watershed with an area of 2.6 km² was established by the Ruhr-University. This site situated in North Rhine-Westphalia were used to provide the input data for the application of this model. The hillslope characteristics needed are geomorphological characteristics as slope, width variation of hillslopes etc.. To validate the simulation results of the kinematic wave model, measured data of soil moisture dynamics (volumetric soil moisture content and groundwater seepage) for the instrumented hillslope are used.
The paper presents some necessary theoretical background of the kinematic wave model with regard to the finite differences discretization of the continuity equation and Darcy-type equation. The processing of input data is demonstrated by the example of the experimental watershed and an instrumented hillslope. The adapted experimental devices and the methodology used in this investigation are described. The spatial and temporal discretization and the boundary and initial conditions are specified. In order to validate the model simulated results are compared with measured time series. In the conclusions field studies and numerical simulations have shown that plane and profile curvature are the most significant topographic controls over subsurface flow and saturation along hillslopes.