Context: A deep monsoon depression over the west-central Bay of Bengal resulted in downpours, severely affecting the city of Hyderabad as well.

More on the news:

  • Monsoon depression originally refers to a low-pressure system affecting the North Indian Ocean and the Bay of Bengal in summer.
  • Recently, the monthly average rainfall of Hyderabad for October was surpassed on a single day when 192 mm of rain fell.
  • Damages
    • At least 24 people were killed and several localities submerged and isolated following incessant rains and the overflowing of the city’s lakes.
    • Overflowing of lakes: In particular, the Hussain Sagar Lake in the middle of the city and the breaching of stormwater drains. 

The inadequate response towards disaster management 

  • Lack of preparatory strategies: 
    • This is rare and a rain-related disaster event. However, the extent of the damage and the turmoil shows a lack of preparation and disaster mitigation, a problem that plagues most urban places in the country.
  • Increased human activities through rapid urbanization: 
    • Construction over lake beds and encroachments of drainage channels have been identified as problems that have exacerbated flooding and inundation in the city.
    • No proper steps have been taken to unblock existing storm drains over the last decade.
    • The existing storm drains have not been enough to handle the requirements of the city, which still depends upon an antiquated sewerage and drainage system.

Urban Flooding:

  • Urban flooding is significantly different from rural flooding- urbanization increases flood risk by up to 3 times, increased peak flow results in flooding very quickly. 
  • Further, it affects a large number of people due to high population density in urban areas

Worrying frequency in urban India for at least 10 years. 

  • Pune is facing the fury of torrential rains for the second consecutive year. 
  • Chennai faced a crippling flood five years ago, Guwahati gets submerged almost every year. 
  • Patna, Bengaluru, Delhi, and Mumbai have their monsoon travails and Hyderabad received its heaviest September rainfall in more than 100 years last year.

General cause factors of urban floods

  • Rapid expansion and haphazard planning:
    • As Indian cities have expanded, they have wrested areas that were once major drainage points. 
    • At the same time, stormwater drains in most Indian cities remain locked in decades-old networks and are most often clogged. 
    • This means excessive rainfall gets trapped within city boundaries
    • An analysis by the Centre for Science and Environment in 2016 revealed that 3,245 hectares of water bodies were lost in Hyderabad between 1989 and 2001. 
  • Climate change 
    • Climate vagaries of the last two decades have exacerbated the problem of urban flooding. 
    • This year, Mumbai received 80 percent of its August rainfall in the first five days of the month, parts of the city that have rarely been flooded were underwater. 
    • More than one IPCC report has pointed to the climate vulnerability of coastal areas such as Mumbai and Chennai.
  • Government programs without proper attention to climate vulnerability
    • It’s unfortunate that recent technology-enabled initiatives — the Smart Cities Project, for example — have very little by way of bolstering climate adaptability. 
    • Also, according to a 2018 report by the Centre for Research on the Epidemiology of Disasters, more than 55 percent of India’s smart cities are prone to floods.

Way ahead:

  • Remodeling drainage system: Cities such as Hyderabad urgently need to expand and remodel its drainage system. 
  • Maintaining the water bodies
    • Besides lakes and canals, wetlands and watersheds play a vital role in absorbing excess rainfall, however, rapid urbanization in the twin cities has resulted in the loss of a large portion of the wetlands. 
  • Hydro-geological urban planning
    • In the long term, the effects of flooding due to deluges can only be mitigated if urban planners take into account the hydro-geology of cities.
    • They need to ensure that construction, development, and land occupation do not take place in a way that reduces the area of wetlands.
  • Area-specific initiatives
    • The solutions could vary according to local conditions and climate adaptability could be an adroit mix of natural and technological means — 
    • Few means such as sensors in drains that warn of floods tried in Buenos Aires and some US cities can be implemented.

According to estimates, more people will live in urban centres in India compared to the rural ones by 2050. It’s imperative that while planning for houses, roads, hospitals and other infrastructure, policymakers respect an area’s hydrology. 

Image Source: TOI

Source: TH