Retention efficiency of a narrow perennial herbaceous buffer zone for surface runoff of solid particles on high and low slopes: case study of Salardareh River

Abstract

This study aimed to assess the role of a narrow perennial herbaceous buffer zone (NPHBZ) in attenuating surface runoff [of] solids under low and high slopes. The portable rainfall simulator was used to simulate surface runoff. The simulated surface runoff collected at 2 and 4 m distances from the edge of each site and solid particles in collecting samples were compared using a reference plot. Retention efficiency (RE) in site 1, at 2 and 4 m widths, for variables: total solid, total suspended solid, turbidity and electrical conductivity (EC) were 60–76%, 69–76%, 53–68% and 28–23%, respectively. Similarly, measurements in site 2 are as follows: 67–78%, 68–78%, 54–61% and 15–21%. Except for the EC of surface runoff in site 1, the particles transported in both sites were significantly reduced. By increasing the width, RE was also increased. This demonstrates that NPHBZs have a positive effect on receptive surface runoff quality.