Assessment of Extreme Storm Conditions for an Urban Drainage System

Abstract

Urban flooding is a combination of natural and anthropogenic hazards which is of major concern to the various stakeholders in society. It causes discomfort and retardation to the fast-moving life of the urban conglomerate and poses a challenge to the water professionals. A drainage network is designed and installed in a city to quickly drain off the excess runoff from the catchment without causing any disturbance to the life. This study focuses on the frequency analysis of past rainfall data and assesses the extreme storm condition for a typical drainage system. Multiple scenarios for simulating rainfall-runoff response to different shapes of hyetograph were studied to analyze the performance of the drainage system. The hyetograph peaks of design storms were primarily rearranged to different time steps of simulation period to study the change in overall response of urban drainage system in terms of flood duration, number of flooding nodes, and flood volume. The MIKE+ is used to conduct a comparative analysis of a part of Gurugram City, Haryana, India, which is a major economic center. The results of the study show that the maximum flood volume is corresponding to the hyetograph designed using the alternate block method.