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Tide Height Modeling and Storm Surge Warning System

Solution Overview

Mumbai Maritime Board's modelled tide height data serves as a critical input for predicting high-tide timings and issuing storm surge warnings during extreme weather events.[1][5][6] This approach addresses the city's vulnerability as an island metropolis where high population density and coastal location create extreme risk from rising sea levels and coastal flooding.[9] The technology integrates hydrodynamic models and storm surge calculations to assess tide and storm surge impacts on the coastal city.[4]

Technical Components

The system utilizes hydrodynamic models and storm surge models to calculate tide and storm surge impacts on Mumbai as an island city with connectivity to the sea.[4] Mumbai Maritime Board's modelled tide height data provides the foundation for predicting high-tide timings and generating storm surge warnings during extreme weather events.[1][5][6][7][8] A web GIS-based decision support system was built to calculate the vulnerability and risk of elements exposed to flood.[4] However, modelled data has limited accuracy in predicting future risk projections compared to monitored data.[1] The Indian National Centre for Oceans Information Services (INCOIS) tide gauge data is not used by any department or agency in Mumbai for planning decisions, despite the city's tide gauge—installed by the British East India Company in the late 1800s—being the only observatory in the country offering more than a century's worth of sea level measurements.[1][7]

Implementation Details

The Municipal Corporation of Greater Mumbai approached the Ministry of Earth Sciences (MoES) to develop an Integrated Flood Warning System for Mumbai referred to as IFLOWS-Mumbai.[4] This initiative represents a joint effort between the Ministry of Earth Sciences (MoES) and the Municipal Corporation of Greater Mumbai (MCGM), also referred to as Brihanmumbai Municipal Corporation (BMC).[2][3][4] The Flood Warning System was formally launched jointly by Honorable Shri Uddhavji Balasaheb Thackeray, Chief Minister of Maharashtra, and Dr. Harsh Vardhan, Union Minister for Health & Family Welfare, Science & Technology, Earth Sciences, on June 12, 2020, at 12:30 hours in Mumbai.[4] In the two years preceding this launch, researchers conducted studies to provide real-time weather information by measuring the city's rainfall, drainage capacity, topography, land use, infrastructure development, population, lakes, creeks, and river bathymetry data for all rivers including Mithi, Dahisar, Oshiwara, Poisar, and Ulhas.[3] The system incorporates weather models from National Centre for Medium Range Weather Forecasting (NCMRWF) and India Meteorological Department (IMD), field data from rain gauge network stations established by Indian Institute of Tropical Meteorology (IITM), MCGM, and IMD, plus thematic layers on land use and infrastructure provided by MCGM.[4] The land topography, land use, infrastructure, and population data provided by MCGM was integrated into a Decision Support System to accurately estimate flood levels at ward level using thematic layers in GIS.[4] Mumbai became only the second city in the country after Chennai to receive the IFLOWS system.[3]

Benefits and Impacts

The integrated approach enables authorities to issue storm surge warnings during extreme weather events by predicting high-tide timings using Mumbai Maritime Board's modelled tide height data.[1][5][6][7][8] The web GIS-based decision support system calculates the vulnerability and risk of elements exposed to flood conditions.[4] The system provides ward-level flood level estimates by integrating land topography, land use, infrastructure, and population data through thematic layers in GIS.[4] BMC is recommended to integrate monitored data into planning and decision-making for improved accuracy, given that modelled data has limited accuracy in predicting future risk projections.[1]

Climate Adaptation Relevance

This system directly addresses Mumbai's extreme vulnerability to coastal flooding and rising sea levels, which pose significant risks given the city's high population density and coastal location.[9] The approach responds to the city's increasing flood periodicity, exemplified by the August 29, 2017 flood that brought Mumbai to a standstill.[4] Machine learning model projections of sea level rise impacts reveal that Mumbai faces the highest flood risks, particularly under high emission scenarios.[9]

Business Analysis

The implementation represents a government-led initiative involving coordination between the Ministry of Earth Sciences (MoES) at the national level and the Municipal Corporation of Greater Mumbai at the municipal level.[2][3][4] The formal launch by the Chief Minister of Maharashtra and Union Minister for Health & Family Welfare, Science & Technology, Earth Sciences demonstrates high-level political support for the flood warning infrastructure.[4] The system leverages existing institutional capacity from multiple national agencies including National Centre for Medium Range Weather Forecasting (NCMRWF), India Meteorological Department (IMD), and Indian Institute of Tropical Meteorology (IITM), creating a collaborative framework for flood risk management.[4] The recommendation that BMC integrate monitored data into planning and decision-making suggests ongoing opportunities for system enhancement and accuracy improvements.[1]

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