Application of a two-dimensional model to calculate water balance of an agricultural hillslope

The objective was to simulate runoff production on an agricultural hillslope in Southern Finland. Water balance was calculated using a quasi-two-dimensional model describing vertical soil moisture distribution and horizontal water movement along a hillslope strip. The model accounted for the production of saturated overland flow on the exfiltration part of the hillslope. The model results were assessed against measurements of surface runoff, subsurface drainage flow, and water table level, which were available at individual field sections for years 1995-96. Intensive runoff events during summer and autumn rainfalls were the primary focus in the modeling application. The model performed well during wet periods when water table remained close to the soil surface, but the results were less satisfactory during dry periods.