Influence of geotextile coverage on vegetation growth and soil slope erosion resistance

Abstract

Geotextiles and vegetation are often used to mitigate slope degradation caused by soil erosion. While their individual effects have been widely studied, geotextile coverage on slope vegetation growth and the erosion resistance of vegetated slopes is less studied. This study aims to reveal the effects of various geotextile coverages on plant growth, as well as the combined impact of different geotextiles and vegetation on slope runoff and soil erosion. To achieve this, large-scale physical model tests were conducted, considering different slope angles and rainfall intensities. Six slope protection modes were investigated, incorporating two types of vegetation: tall fescue and Cynodon dactylon, in combination with three types of geotextiles: coir geotextile, straw geotextile, and a coir-straw mixed geotextile. The results indicated that geotextile coverage could retain more water on the slope, which is beneficial for the germination and growth of vegetation. Among all six slope protection modes, the combination of tall fescue with coir geotextile was the most effective, reducing the runoff rate by 70% and the erosion rate by 94%. Furthermore, correlation analysis between rainfall intensity, slope angle, slope protection modes, and runoff and erosion rates revealed that slope angle exhibited the strongest correlation with soil and water loss.