Experimental Study on the Inlet Discharge Capacity under Different Clogging Conditions

Xiaoli Hao,Hongjian Shi,Jie Mu

doi:10.3390/w13060826

Abstract

Storm drainage inlets transport urban runoff and discharge to underground sewer systems. If the inlet structure is blocked, the urban drainage system is hampered, leading to urban flooding. To quantitatively analyze the influence of clogging conditions on inlet discharge capacity, laboratory experiments were conducted to address the impact of different inlet clogging conditions on inlet discharge capacity under different upstream discharge conditions. These were based on a two-layer platform that mimicked a complete inlet structure including a drainage grate, a rainwater well, and a connecting pipe. The results show that the water flow near the inlet was similar to weir flow when the rainwater well was not full, whereas the water flow state near the inlet behaved similarly to orifice flow after becoming full. In addition, it was found that the clogging extent and position can significantly influence the comprehensive discharge capacity of the street inlet. The experimental dataset was used to calculate the inlet discharge coefficients of the weir and orifice flow states under different clogging conditions. The results are applicable to research addressing the formation mechanisms of urban floods. Additionally, this study is of practical significance for early warning systems and emergency response support during heavy rainfall.

Highlights

Urban inundation due to rapid urbanization and climate change is a serious problem for many cities worldwide, which affects human life and property [1,2,3,4,5,6,7,8]
A detailed description of experimental phenomena and relevant experimental analysis are presented, and the inlet discharge coefficients are calculated by taking different clogging conditions into account
The study results show that the clogging extent and the clogging position have a significant influence on the discharge capacity of the street inlet, and the clogging extent has a greater impact on the inlet discharge capacity than the clogging position

Summary

Introduction

Urban inundation due to rapid urbanization and climate change is a serious problem for many cities worldwide, which affects human life and property [1,2,3,4,5,6,7,8]. The increased worldwide flood events in recent years have attracted the attention of many scholars seeking to understand the urban drainage process This interest has led to several studies describing the hydraulic performance and discharge capacity of different inlet types [13,14,15,16,17,18]. The hydraulic behavior of the storm drainage system could be affected by clogging, which is caused by surface runoff carrying leaves, plastic bags, and other debris during heavy rainfall events [19]. This is a notable cause of urban flooding [12,20,21]

Methods

Results

Discussion

Conclusion