Effectiveness of bioengineering and geosynthetic integration for riverbank erosion control: A case study along the Mae Taeng River, Chiang Mai, Thailand

This study evaluates the performance of erosion control measures incorporating geosynthetic materials and bioengineering approaches to mitigate riverbank erosion along the Mae Taeng River in Chiang Mai Province, Thailand. Four experimental field plots were established under different conditions, including geogrid mats with tensile strengths of 2, 10, and 20 kN/m, partial versus full surface coverage, and an untreated control plot. Riverbank cross-sectional profiles were monitored at two-month intervals over a 10-month period. Erosion resistance was assessed using a submerged jet test, while slope stability was analyzed using SLOPE/W and BSTEM numerical models. The results indicate that the plot treated with high-tensile geogrid mats combined with full surface coverage and vegetation exhibited the lowest erosion rate and the highest slope stability. Field measurements showed a reduction in erosion extent by 87.90% and an increase in the factor of safety (FS) by 22.64%, accompanied by a decrease in the erodibility coefficient from 10.23 to 0.19 cm 3 /N·s. Numerical simulations further demonstrated strong agreement with field observations, with an RMSE of 0.211 and an NSE of 0.958. These findings suggest that integrating bioengineering strategies with geosynthetic materials provides an effective and practical solution for riverbank erosion control in tropical riverine environments.