Hydraulic Analysis of Biochannels for Sustainable Urban Drainage Systems

Abstract

This study focuses on employing channel lining materials that includes Turf Reinforcements Mat (TRM) and Erosion Control Blanket (ECB) as bioengineering techniques for erosion control. Hydraulic characteristics of flow through these materials were determined in terms of flow velocities and shear stresses. The experimental results indicated that the average velocity for TRM ranges between 0.6 to 3.5 m/s, while that of ECB varies from 0.7 to 4.1 m/s. Also, TRM has shear stress values of 1.950 N/m3 for bed and 1.575 N/m3 for bank respectively of test channel when the flow depth was 15cm. While ECB has shear stresses of 2.138 N/m3 for bed and 1.721 N/m3 for bank for same flow depth of 15cm. However, when the flow depth is 5 cm, TRM has values of 0.972 N/m3 for bed and 0.769 N/m3 for bank, and ECB gives 0.957 N/m3 for bed and 0.766 N/m3 for bank of test channel. Hence, the greater the flow depth, the higher the velocities and shear stresses respectively. Conversely, lower flow depths lead to velocities and shear stresses that are within the allowable standards for designing a stable channel. Generally, TRM performed the best for having higher shear stresses compared to ECB.