Author(s): Yafei Jia, Lindsey Yasarer, Robert Wells, Martin Locke, Richard Lizotte, Ron Bingner

Linked Author(s): Yafei Jia

Keywords: Overland flow; Numerical simulation; Soil erosion; Model validation; Beasley Lake Watershed;

Abstract: Soil erosion from farmlands results in top soil and nutrient loss, and forms gullies on the landscape downgrading the productivity and cultivability. To study the soil and gully erosion process over a landscape, the methods of physical experiments, field observation and numerical simulations are often used. In this paper, a physically based hydrodynamic model, CCHE2D, is applied to simulate the watershed hydrologic processes. CCHE2D is a finite element based, depth-integrated two-dimensional hydrodynamic model. It has been modified to simulate the rainfall induced overland flow process in experimental and field-sized watersheds. In this paper, CCHE2D was modified further to simulate soil erosion processes in an agricultural watershed in the state of Mississippi, Beasley Lake Watershed (BLW). This low relief agricultural watershed is about 6.25 km2 in size, including an oxbow lake, wetlands, croplands, and woods. The natural topography and runoff patterns are modified by culverts, slotted inlet pipes, and ditches. The detailed overland flow patterns and hydrologic processes in BLW and sub-watersheds can be simulated without predefining a channel network and sub-watersheds. Soil erosion and sediment transport caused by storm events were also simulated in one of the sub-watersheds. Comparisons showed reasonable agreements between the simulated and measured hydrographs of water flow and sediment loads. The physically-based model showed its applicability to simulate overland flows, soil erosion, and sediment transport on hill slopes and provided distributed solutions.

DOI: https://doi.org/10.3850/38WC092019-1084

Year: 2019