Infiltration and Runoff Response from a Complex Soil Plot

An integrated measurement and modeling study was conducted to evaluate the effects of plot complexity and differences in soil hydrologic response on measuring and modeling infiltration and runoff processes. Experiments using a variable intensity rainfall simulator were conducted on a 2 m by 6 m soil box lysimeter packed with two soils with different infiltration capacities with two different plot configurations. Rainfall application rates varied between 50 and 200 mm/hr. Results of the rainfall simulator experiments found differences between the hydrologic responses of the two soils to changes in applied rainfall intensity. The study also showed that the location of the two soils relative to each other in the soil box did have an important effect on runoff response and that the response changed with changes in rainfall intensity. A distributed, process based hydrologic simulation model was used to model the complexity of the plots. The results of the simulation model showed the difficulty in accurately modeling the hydrologic response from heterogeneous soil plots.