One way to estimate spatial distribution of water content at the soil surface consists of using active microwave remote sensing. It has been theoretically and experimentally demonstrated for unsaturated conditions. Nevertheless, radar data are ambiguous when ponding conditions occur, as in variable source areas, due to the contradictory influence of the dielectric effect and the specular effect on the backscattering attenuation coefficient, &sgr;0. A procedure is considered, based on a topographic analysis, to take into account the influence of the two effects on radar response. The present results stress the capabilities of the ERS (European Remote Sensing Satellite) radar to survey saturated areas in time and space.