With the rapid rise in flooding events induced by climate change across
the globe, effective flood management strategies through modelling have
garnered attention over the years. In the present study, we propose a
holistic hydrodynamic flood modelling framework to derive the flooding
extent. Various hydraulic scenarios are integrated into the framework
which consider different combinations of cross-section and lining
material options along the river channel for this purpose. A 3-way
coupled flood model has been developed in MIKE FLOOD platform, over
Mithi river catchment an extremely flood-prone area in Mumbai, the
financial capital of India. Flood influencers such as precipitation,
flows through the channel, overland, storm-water drains, and tidal
influences are considered to generate flood inundation and hazard maps
for the scenarios. The dearth of data in the model is met by
implementing alternate robust procedures to compute the design values of
the influencers. Subsequently, the maps are derived for different return
periods of design precipitation, tidal elevation and streamflow values
to identify the most desirable scenario. The proposed framework
efficiently determines that the scenario having trapezoidal river
cross-section with concrete lining material maximizes the decrease in
spatial extent of flood in comparison to the other scenarios. This
user-friendly generic approach can be potentially executed as an
effective flood mitigation option in thickly populated and socially
vulnerable regions where lack of space limit the implementation of
structural measures for flood management. The framework can prove
instrumental particularly for the developing and under-developed
countries where application of these strategies is hindered by
inadequacy of data.