Runoff Interception Characteristics of a Y-Shaped Bamboo Structure for Slope Protection

Abstract Conventional slope protection systems are susceptible to runoff-induced erosion, surface-soil loss, and shallow soil deformation under rainfall conditions. This study developed a Y-shaped bamboo structure integrating runoff interception and seepage drainage functions. Model tests and theoretical analysis were conducted to investigate the runoff interception efficiency of the structure under simulated rainfall conditions. The results showed that the Y-shaped bamboo structure exhibited effective runoff interception performance, with the cumulative intercepted runoff increasing approximately linearly with rainfall duration. The included angle between the two wings had the greatest effect on runoff interception efficiency, followed by wing length and wing diameter, with these three parameters collectively accounting for 93.04% of the total variance. Furthermore, a theoretical runoff interception model coupling weir flow theory with Darcy's law was developed and validated against laboratory model tests, showing good agreement with the experimental results. The findings provide a theoretical basis for geometric optimization and support the potential application of Y-shaped bamboo structures in ecological slope protection.