Submitted to: American Society Of Civil Engineers Watershed Management Conference
Publication Type: Proceedings
Publication Acceptance Date: 2/1/2000
Publication Date: 6/20/2000
Interpretive Summary: Understanding both infiltration, the movement of water into soil, and runoff is important for land managers. A study was conducted to evaluate the effects of differences in soil plots on measuring and modeling infiltration and runoff processes. A series of experiments were conducted using a rainfall simulator to determine differences in runoff from two different soil plots when different rainfall rates were applied. Each of the two soil plots had the same soils, but the soils were placed in different locations on the plots. The rainfall application rates were varied during the experiment. The study showed that the location of the two soils has an important effect on runoff, and that the effect changed with changes in rainfall. A hydrologic simulation model was used to model infiltration and runoff on the two plots. The results of the simulation model showed the difficulty in modeling infiltration and runoff processes on plots with two different soils.
Technical Abstract: 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 in 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 response 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 within 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.