Construction and simulation of distributed hydrological and erosion prediction models at small-scale watersheds in the loess hilly-gully region

摘要

Based on the complex geographic environment found in the loess hilly-gully region , as well as the complicated physical processes of soil erosion, hydrological and erosion mathematical models were proposed in this paper. Hydrological process includes rainfall infiltration, production flow, and convergence. Meanwhile, the erosion process model includes raindrop splash - sheet detachment and deposition , the upslope beam with sheet -rill erosion zone detachment and deposition , and the middle and lower beam rill -ephemeral gully erosion zone detachment and deposition, below shoulder line of valleys with gully and channel erosion detachment and deposition. This paper identified 10 erosive rainfall events at the Heifangou watershed in the loess hilly-gully region of China for parameter calibration. Simulation precision of the hydrological and erosion models reached 81.83 and 70.8%, respectively. Two erosive rainfall events at the Zhifanggou watershed were used to test the model. Results showed that the simulation precision of the runoff and erosion models reached 75 and 69.3%, respectively. These indicate that the proposed models can be used to reasonably simulate rainfall runoff and sediment transport in small-scale watersheds in the study area.