Effectiveness of geotextiles in reducing runoff and soil loss: A synthesis

Abstract

Despite geotextiles having potential for soil conservation, limited scientific data are available to assess the effects of geotextiles in reducing runoff and water erosion. Hence, the objective of this review is to analyse the effects of plot length (L) and other possible affecting factors [cover percentage (C, %), slope gradient (S), rainfall duration (D), rainfall intensity (I), sand, silt and clay contents, soil organic matter (SOM) content and geotextile type (natural or synthetic)] on the effectiveness of geotextiles in reducing soil and water loss, based on reported experimental data. From linear regressions, C (%) and soil sand, silt and clay contents are found to be the most important variables in reducing SLR (ratio of soil loss in bare plots to that in geotextile treated plots) for splash, C (%) for interrill and D (min) for rill and interrill erosion processes, respectively. Soil clay and silt contents and D are key variables in decreasing RR (ratio of runoff from bare plots to that from geotextile treated plots) for interrill, and clay content for rill and interrill erosion processes, respectively. The linear relationship between mean b-value (geotextile effectiveness factor in reducing soil loss) and L of all studies was not significant (PN0.05). The same is true for the relationship between L and SLR, and L and RR. However, when L is added to an equation as an interaction term with C (%), geotextile cover is significantly (Pb0.05) more effective in reducing SLR on shorter plots than longer ones for both interrill and rill and interrill erosion processes. Buffer strip plots (area coverage ∼10%) with Borassus and Buriti mats have the highest b-values.