Monsoon delight: Rain alert on phone every 15 mins
From next year, IITM-developed early warning system to help citizens avoid flooded localities; aid civic officials act swiftly in waterlogged areas.Updated: Jun 29, 2019 05:09 IST
Next monsoon, you are likely to receive an update on the amount of rain for every 500m in the Mumbai Metropolitan Region (MMR) on your phone every 15 minutes.
The Indian Institute of Tropical Meteorology (IITM), Pune, which is under the ministry of earth sciences (MoES), has developed an early warning system to forecast floods for MMR that will help citizens avoid pockets that are flooded and municipal authorities to act swiftly in waterlogged areas. “Climate is changing. We are experiencing more extreme weather events such as heavy rainfall, urban floods and flash floods,” said M Rajeevan, MoES secretary. “While it is easy to forecast tomorrow’s rainfall, it is very difficult to forecast extreme weather events because the science itself is very different. The ministry, therefore, is investing a lot in research in order to improve forecasts for extreme weather events.”
On Friday, Rajeevan was speaking at the Somaiya public lecture titled ‘Global climate change: Causes, concerns and commitments’ at the Vidyavihar campus.
A network of 160 rain gauges has been set up, and four small X-band Doppler radars – two in Mumbai and one each in Thane and Navi Mumbai – with a range of up to 50-60km will be installed next year. There will be continuous radar monitoring, known as Mosaic, across MMR that will provide near real-time weather information.
Experts said a flood early warning system for Mumbai is important because the slope of the Mithi River changes very abruptly – steep from the river’s origin to the Mumbai airport, and changes to being flat – and therefore information on the drainage network is important.
Professor Subhankar Karmakar, Centre for Environmental Science and Engineering, IIT- Bombay, said urban flood early warning system in Mumbai will work successfully only if the BMC and MMRDA provide updated information on the city’s drainage network and a fine resolution digital elevation map for 24 wards. “Urban settlement in Mumbai is very dense, and incorporating the drainage network is crucial. The elevation map will provide information on the level of inundation over land. Based on these two parameters, we will be able to assess the flow of rainwater through drainage and thereby calculate the duration of water logging or floods,” said Karmakar, who along with his colleague professor Subimal Ghosh developed the first early warning system for forecasting urban coastal floods, following the 2015 Chennai floods that cost more than 150 lives.
The Chennai Flood Early Warning System, which will be handed over to the Chennai municipal corporation, however, could not be validated last year due to the absence of heavy rain or floods. With plans to develop early warning systems in every metropolitan across India, the next destination is Bengaluru. “Mumbai often witnesses significant spatial variability in rainfall and Friday’s rainfall was a perfect example of this. The system will improve detection of such localised heavy rainfall events,” said Akshay Deoras, meteorologist and PhD researcher at the department of meteorology, University of Reading, UK.
First Published: Jun 29, 2019 05:09 IST