Journal Article

Effects of Grass Cover on the Overland Soil Erosion Mechanism Under Simulated Rainfall

Zhang, Mingwang, Xia, Junqiang, Zhang, Kuandi, Wang, Pengfei, Cen, Youdong

2025

Overview

Existing research on soil erosion primarily focuses on the individual effects of factors such as rainfall intensity, slope gradient, grass cover, and soil characteristics, with limited exploration of the interactions among these factors. This study investigated the mechanisms of soil erosion on overland covered with vegetation in the Loess Plateau region through indoor artificial simulated rainfall experiments. The experiments included six levels of grass coverage (0, 30%, 40%, 50%, 60%, 70%), five grass distribution patterns (DP, CP, VP, SP, HP), five rainfall intensities (60, 80, 90, 100, 120 mm/hr) and three slope gradients (5°, 10°, 15°) to explore the effects of experimental design factors and hydraulic parameters on the overland soil erosion mechanisms. The results show that as the grass coverage increases, the soil erosion rate on the overland decreases. Under different grass distribution patterns, horizontal grass distribution played an important role in inhibiting overland soil erosion rate. The overland soil erosion rate increased following a power function relationship with rising slope steepness and rainfall intensity, with erosion rates being more sensitive to changes in rainfall intensity than slope gradient. Among the six hydraulic parameters, dimensionless stream power was the optimal hydraulic parameters for predicting overland soil erosion rate under grass cover. Furthermore, an overland soil erosion model under the influence of grass cover and rainfall intensity was established based on general dimensionless hydraulic parameters (KGE = 0.931, R2 = 0.912). The model satisfactorily simulates overland soil erosion rate under grass cover and helps to reveal the mechanism of overland soil erosion. Plain Language Summary Grass cover has a complex influence on overland soil erosion. This study quantified the impact of grass cover on overland soil erosion using a dimensionless water flow path index. It systematically analyzed the response mechanism among overland soil erosion, slope gradient, rainfall intensity, and hydrodynamic parameters, aiming to identify the optimal hydrodynamic parameters capable of characterizing overland soil erosion. A predictive model for soil erosion was constructed based on general dimensionless water flow intensity parameters, comprehensively evaluating the mechanism of soil erosion on grass‐covered overland under simulated rainfall conditions. The results indicate that the model constructed using dimensionless parameters exhibits strong adaptability and can be effectively validated in other experiments. Key Points Systematically analyze the response mechanism of overland soil erosion concerning experimental design factors and hydrodynamic variables Dimensionless stream power is the most effective hydrodynamic parameters for predicting overland soil erosion under grass cover Develop an overland soil erosion prediction model using general dimensionless flow strength parameters

• Publisher: John Wiley & Sons, Inc
• Subject: Adaptability / China / Design factors / Design of experiments / Distribution patterns / Erosion mechanisms / Erosion models / Erosion rates / Experimental design / general dimensionless hydraulic parameters / grass cover / Grasses / Hydraulics / Hydrodynamics / Parameter identification / Parameters / Precipitation / Prediction models / rain / rain intensity / Rainfall / Rainfall intensity / rainfall simulation / Rainfall simulators / Simulated rainfall / simulated rainfall experiments / Slope gradients / Slopes / soil / Soil characteristics / Soil erosion / soil erosion mechanism / soil erosion models / streams / topographic slope / Vegetation / water / Water flow