White Paper
An Integrated Modeling Approach To Predict Flooding On Urban Basin
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•White Paper: An Integrated Modeling Approach To Predict Flooding On Urban Basin
By Dr Ashis Kumar Dey and Seiji Kamioka
Flooding on urban basins is intensifying due to rapid urbanization. Flooding primarily occurs because of drainage congestion of inland flow and/or over bank flow of river during severe rainfall event. Rapid urbanization is causing a major change in rainfall-runoff phenomenon and the drainage system as well. The overland flow pattern is becoming complex due to huge structural development, and therefore, the correct prediction of surface runoff is becoming a challenging issue.
Traditional one-phase sewerage-network model may be able to simulate the drainage system correctly until there is no overflow from the network inlet or manhole. When such overflows exist due to insufficient drainage capacity, then it is difficult to reproduce the actual flooding condition using this traditional one-phase simulation technique. In one-phase simulation one can store the excess water that overflows from a manhole by considering a virtual storage basin above the manhole.
The present integrated model is constructed basically by joining the EXTRAN module of Storm Water Management Model of United States Environmental Protection Agency (EPA-SWMM) and a traditional flood simulation model (FLDSIM) developed by National Institute for Land and Infrastructure Management (NILIM), Japan. EXTRAN module is responsible for the 1D simulation of sewerage-network. FLDSIM module has two different parts: (i) MESHSIM to simulate the 2D overland flow using mesh-network and (ii) RIVSIM to simulate the 1D flow through river-network. MESHSIM and EXTRAN are interconnected through the sewerage inlet or manhole and the flow interaction is limited by a control structure (weir or orifice). RIVSIM and MESHSIM are interconnected through the condition setting for the levee break or bank overtopping and the flow interaction is controlled by series of weir equations developed in NILIM.
Click Here To Download:•White Paper: An Integrated Modeling Approach To Predict Flooding On Urban Basin
