66 - Unravelling the Complexities of Urban Flooding Amidst Drainage Surcharge: Insights from Experimental Research

Urban areas face a heightened risk of inundation when precipitation overwhelms the drainage infrastructure. Understanding the dynamics of urban floods during drainage surcharge events is essential for enhancing urban resilience and safeguarding the well-being of urban populations. Since the surcharge induces a more or less three-dimensional flow in the urban area, the simulation and analysis of the same is quite challenging for a large area. This paper aims to deduce the complex dynamics of urban flooding that transpire during drainage surcharge employing controlled experiments in a 15 m × 4 m laboratory setup consisting of a river network, urban floodplain, road, and drainage network. Flow depth and velocity pattern induced by the surcharge is recorded using ultrasonic sensors and digital single-lens reflex cameras. The MIKE+ software package is used for the numerical simulation of the experimental runs and further analysis. The authors make an effort to validate the weir and orifice equations generally used to represent a drainage surcharge and similar flow events through the experimental data. By replicating drainage surcharge scenarios through physical models and data-driven simulations, authors explore how factors such as drainage system capacity, urban topography, and land use interplay to shape the dynamics of urban floods. The findings shed light on the intricacies of flood propagation, inundation patterns, and numerical modelling of urban floods. The insights gleaned from this research have significant implications for urban planning, emergency preparedness, and the development of resilient infrastructure systems in the face of increasing urbanization and changing climate patterns.