Vegetation has been widely applied in engineering design methods because of its numerous benefits, including preventing soil erosion, improving landscape, and reinforcing the soil structure. To better understand the hydrological influence of vegetation on rainfall infiltration, a numerical simulation approach was proposed to study the effects of grass cover on rainfall infiltration and surface runoff of volcanic soil. The project team realized that they needed flexible geotechnical modeling software to conduct the evaluation.

They selected PLAXIS to perform the numerical unsaturated/saturated seepage analysis and simulation and obtain the outflow and runoff, estimating the soil-water characteristic curves and coefficients of soil permeability. The software’s automated features and refined modeling capabilities greatly enhanced model stability, accuracy, and convergence. Based on the PLAXIS model and experimental results, they achieved a better understanding of the seepage behavior and determined that grass cover plays a key role in reducing the rainfall infiltration into the volcanic soil.