Simulation experiment on the influence of vegetation pattern on soil infiltration and water and sediment process

Reasonable vegetation pattern can improve soil infiltration performance and erosion resistance, effectively reduce runoff and sediment yield, balance the relationship between soil erosion prevention and soil water conservation, and then promote the improvement of the ecological environment. In the plot scale, based on artificial simulated rainfall, the soil infiltration, runoff, sediment production characteristics and soil storage of various vegetation patterns biomass density(0, 50%, 100%) and distribution methods(concentrated distribution on the upper of the slope, concentrated distribution on the lower of the slope, uniform distribution) were studied. The results show that among the Philip model, Kostiakov model, and Horton model used to simulate the slope infiltration process, the Horton model has the best fitting results. The change trend of runoff rate of different vegetation patterns is basically the same, which can be roughly divided into two stages: rapid growth in the initial stage, slower growth in the middle and later stages and gradually tending to a stable state. The variation trend of sediment yield varies slightly with the vegetation pattern. Compared with the runoff process, the sediment production process changes drastically and has poor regularity. Overall, reducing biomass density can increase runoff(from 19.21 mm to 25.44-38.09 mm to 51.79 mm) and erosion(from 118.97 g/m~2 to 237.57-597.90 g/m~2 to 1400.29 g/m~2), as well as soil moisture is better preserved. The concentrated vegetation pattern under the slope, such as the form of vegetation filter belt, can best control both soil erosion and soil water consumption. Comprehensively considering soil erosion prevention and soil water consumption, it is recommended to use a vegetation pattern with appropriate density(110 g/m~2 in this study) and concentrated distribution near the exit.