Curb Inlet Efficiency Evaluation under Unsteady Rainfall Situations Based on Full-Scale Rainfall-Runoff Experiments

Abstract

Bioretention facilities have commonly been used to reduce the runoff volume, peak discharge, and pollution in runoff to the downstream drainage system during sponge city construction. The curb inlet interception efficiency determines how much of the runoff from the road surface enters the bioretention cell directly. Most previous studies have focused on the method of designing the curb inlet itself, whereas few have paid attention to evaluating the curb inlet efficiency in unsteady rainfall situations. In this study, a full-scale rainfall simulation system and a road surface with a curb inlet were built to examine the curb inlet efficiency under such conditions. It was found that methods from the literature for predicting the curb inlet efficiency produced large errors in small rainfall (low runoff depth of upstream inflow) situations. Therefore, a modified method was proposed based on experimental results to evaluate the curb inlet efficiency more accurately under unsteady rainfall situations.