Studies on the water balance of a small natural catchment area in southern Sweden

A water balance study is made on a small natural catchment area in flat sandy agricultural country in southern Sweden. Relevant simultaneous data concerning precipitation, evapotranspiration, surface run-off and ground moisture content are obtained from measurements over a period of at least six years. Complete balance between precipitation, evapotranspiration and surface run-off is obtained from the six-year period as a whole. The results show a significant and very pronounced pattern of seasonally influenced subsurface inflow and outflow. When represented as running 12-month means, the surface run-off and ground water level curves show a high degree of correlation to long term variations in precipitation. The ground water is found to lag 6 months behind the precipitation and the run-off 2 or 3 months. The running 12-month mean for evapotranspiration is found to vary only slightly and does not appear to be related to the precipitation.