EFFECTS OF TOPOGRAPHY AND SOIL PROPERTIES ON RECHARGE AT TWO SITES IN AN AGRICULTURAL FIELD

Description of field techniques for soil properties and dye and CFC movement through the unsaturated zone of plain sands. Unsaturated zone water balance method, groundwater recharge and hydrograph analysis of water table are described. Chlorofluorocarbon age dating technique is examinated.Ages of water migration are evaluated from the concentrations of CFC-12 assuming recharges temperature of 7 and 9 °C. Variations of wetting fronts are discussed accross seral factors : surface runon of water and soil heterogeneities.