Getting area-wise details about the inundation during the monsoon time in Chennai would be possible now. The sensational piece of information is TN would soon deploy an intelligent flood warning system in Chennai to help the officials to get area-wise details about inundation. It is important to note that the technology termed ‘CFLOWS’ is India’s first integrated coastal flood warning system.
Information collected is after the 2015 Chennai floods CFLOWS has been conceptualized by the office of the Principal Scientific Advisor to the union government. Urban flooding has become common in major cities like Chennai, Mumbai, etc. It is now said that this ‘CFLOWS’ would be a game-changer in these major cities. It is India’s first integrated coastal flood warning system. It was conceptualised by the office of the Principal Scientific Adviser to the Union Government, after the devastating 2015 Chennai floods.
The CFLOWS system
The system is being considered a game-changer, not just for Chennai, but also for other coastal cities such as Mumbai where urban flooding has become the norm. The link to the fully-operational CFLOWS will be formally handed over to the State Disaster Management cell on Friday, by the National Centre for Coastal Research (NCCR).
J Radhakrishnan, the officer who heads disaster management and mitigation in Tamil Nadu, said CFLOWS would be deployed immediately. It would be tested for 1-2 weeks before being integrated with TN-Smart, the State government’s disaster management portal.“To begin with, the system is designed for core urban area of the city, spread across 426 sq.km. Later, it will be extended to cover the Greater Chennai Corporation limits, for which work is underway,” he said.
How the CFLOWS system works
Though CFLOWS as a product is fully operational, its accuracy depends on the quality of inputs. For instance, IMD has only two automatic weather stations in Chennai. If the forecast says 20 cm rainfall for Chennai, the system will assume all the areas in the city will receive 20 cm, which may not be the case. To improve accuracy and get more localised results, it is pivotal to enhance the number of weather stations.
Mrutyunjay Mohapatra, Director-General of Meteorology, IMD, acknowledged that the number of weather stations has to be increased. “We have plans to add 30 more stations in Chennai.”
- It’s an integrated GIS-based decision support system to provide forecast on potential inundation 10 days in advance
- Ministry of Earth Sciences and TN government have jointly developed it
- It will be hosted and made operational at NCCR with meteorological data inputs from IMD, NCMRWF and INCOIS
- The system can simulate the scenario and predict what will happen in a particular area
- It has 6 modules, including 3D visuals of flooding in infrastructure, buildings, roads and ward boundaries
- Mirror images of CFLOWS will be setup in CRA, Greater Chennai Corporation and IMD
Why Chennai is prone to flooding
Chennai is prone to flooding due to a combination of topography, high population density and unplanned rapid urbanisation.
Though it is blessed with three natural drainage systems- Cooum, Adyar and Buckingham Canal, the city literally went underwater in 2015 with three consecutive weather systems bringing unprecedented rain.
As per Mr. M.V. Ramamurthy, NCCR director, CFLOWS is a web GIS-based decision support system and it would integrate data and outputs derived from weather forecast, hydrologic, hydraulic and hydrodynamic models. He explained how based on these models a flooded library having 796 flood inundation scenarios was developed corresponding to different rainfall return periods, tidal and water discharge conditions. It must be noted that as per the needs of the TN government a complete Web GIS-based decision support system has been built with 6 modules. The system would be tested in this monsoon.