Abstract
This study demonstrates that under a steady state in response to ranifall supply with a constant intensity, the pressur-head distribution in a sloping rectangular domain can be approximately categorized by three zones: the I zone with vertical unsaturated flow, the U zone with unsaturated downslope flow, and the S zone with saturated downslope flow. Two horizontal distances representing the end point of the I zone and the start point of S zone are calculated as their delimiters from the soil hydraulic properties, topographic properties, and rainfall intensity. An introduced dimensionless number is well controling the topological classification of these three zones.
