Integrated modeling for simulating sediment production and transport in agricultural landscapes

Authors: LEE, SANGHYUN - University Of Illinois; CHU, MARIA - University Of Illinois; GUZMAN, JORGE - University Of Illinois; Flanagan, Dennis; Moriasi, Daniel; Fortuna, Ann Marie; Starks, Patrick

Submitted to: Environmental Modelling & Software
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/6/2022
Publication Date: 12/10/2022
Citation: Lee, S., Chu, M.L., Guzman, J.A., Flanagan, D.C., Moriasi, D.N., Fortuna, A., Starks, P.J. 2022. Integrated modeling for simulating sediment production and transport in agricultural landscapes. Environmental Modelling & Software. 160. Article 105605. https://doi.org/10.1016/j.envsoft.2022.105605.
DOI: https://doi.org/10.1016/j.envsoft.2022.105605

Interpretive Summary: Soil erosion is a national and international problem, as it can decrease crop production and also decrease off-site water quality. Computer simulation models are often used to estimate the amount of runoff and soil loss from different fields having different soils, slopes, and land management practices. In this study, we created a new model that combined components of the Water Erosion Prediction Project (WEPP) hillslope model (typically applied to small fields) with a large-scale watershed model (typically applied to much larger areas). We then tested how well the modeling system performed when applied to measured experimental data from USDA-ARS watersheds in Oklahoma. Results showed that the new system could adequately represent the runoff and sediment losses under two very different land management systems. These results impact scientists, engineers, university faculty, students, and other involved in modeling large hydrologic watersheds and assessing soil erosion and sediment losses.

Technical Abstract: A new modeling platform was presented to simulate spatially distributed sediment production and transport in agricultural landscapes. The sediment production at the grid scale was computed using the stand-alone Water Erosion Prediction Project-Hillslope Erosion code while sediment transport was represented by an advection-dispersion equation. The performance of the model was tested in the Water Resources and Erosion watersheds at the Grazinglands Research Laboratory, El Reno, OK, USA. Results showed that this modeling approach was able to capture the complex behavior of sediment under different management practices in the watersheds. The modeling framework provides mechanistic processes in simulating the fate and transport of sediment across the watershed at spatio-temporal scales that are useful in assessing the environmental impacts of management schemes. Therefore, this study is expected to help redefine the current approaches to estimating soil erosion by bridging scale differences to capture the large-scale effects of small-scale soil erosion processes.