The National Remote Sensing Centre is hosting an experimental map showing low-lying vulnerable areas in Hyderabad. The map shows the contours of land and the areas that are likely to be flooded in the eventuality of heavy downpour. “The map if it can be juxtaposed with the 13 watersheds of the River Musi and Doppler radar information it will give a lead of three hours for planners and citizens,” says Marri Shashidhar Reddy former vice-chairman of the National Disaster Management Authority.
The map dovetails perfectly with the wishes of Mr. Reddy. Earlier in 2017, the Disaster Management Cell of Greater Hyderabad Municipal Corporation had released information about 116 water stagnation points in the city. It also identified the number of families that need to shifted to higher grounds in the event of flooding. In contrast, the NRSC map of vulnerable areas of city is actionable. On Tuesday night and Wednesday when the water from Osmansagar and Himayatsagar reservoirs was released, the areas swamped included the exact area which the map showed. It also shows the low-lying area of Manchirevula which was flooded isolating communities in the area.
“The floods will become frequent in urban areas as the intensity of rainfall is increasing and the runoff increases,” said Kapil Gupta of IIT-B at a recent seminar. He shared data about how cities in India have been frequently experiencing rainfall >50mm/hour and even >100mm/hour.
“We need meteorological leads provided by Doppler Radar and hydrological information provided by NRSC to map localities. Rain at one or two places in Telangana doesn’t make sense. We should be able to tell people which area will get rain and where the runoff will flow,” says Mr. Reddy.
Hyderabad has seen frequent scattered urban flood events from August 24, 2000 flooding that impacted Begumpet after a deluge of 241.5 mm was recorded. In 2016 it was Allwyn Colony and Bandari Layout, in 2017 it was East Anandbagh Colony, in 2020 it was Falaknuma and Nadeem Colony and in 2022 it was Narsingi and Manchirevula.
While Hyderabad had very few rain gauges in 2000 it now has a mine of weather data. The Telangana State Development Planning Society hosts data from a network of over 1,044 automated weather stations throughout the State and nearly 132 in Greater Hyderabad Municipal Corporation limits which gets updated every hour 24 X7.
While the Indian Meteorological Department’s Doppler radar goes offline often, the TSDPS data gets automatically updated.
Recent high precipitation
August 24, 2000 — 241.5 mm in Begumpet
July 21, 2012 — 226.8 mm in Saroornagar
September 21, 2016 — 230.2 mm in Qutbullapur
October 14, 2020 — 300 mm in Hayathnagar
2000 flood was followed by one in 2001, 2002, 2006, 2008, 2013, 2016 and 2020
