CHENNAI FLOODS: A WAKE-UP CALL FOR URBAN PLANNERS

THE CONTEXT: Cyclone Michaung has disrupted life in Chennai. Cyclone made its landfall in Andhra Pradesh on December 5. Heavy rainfall caused floods, submerging houses and halting communication services, at least 20 people have lost their lives.

MORE ON THE NEWS

• On December 1, the Joint Typhoon Warning Centre (JTWC), a joint U.S. Air Force and Navy command, upgraded the likelihood of cyclone formation to high.
• By December 2, the depression had intensified into a deep depression, as expected, while it was around 500 km southeast of Chennai and moving at around 17 km/hr.
• On December 5, Cyclone Michaung (pronounced mig-jaum) made landfall over Nellore in Andhra Pradesh as a super-cyclonic storm.
• A day earlier, the weather system had produced 150-200 mm of rain in north Tamil Nadu.

ABOUT CYCLONE MICHAUNG

• Severe Cyclonic Storm Michaung was a strong tropical cyclone that formed over the Bay of Bengal off the south-eastern coast of India.
• It originated as a low-pressure area in the Gulf of Thailand and crossed into the Bay of Bengal which became a deep depression on December 2.
• It developed into a cyclonic storm thereafter and was named Michaung.

HOW ARE CYCLONES NAMED?

• In 2000, a panel of the World Meteorological Organisation together with members of the United Nations Economic and Social Commission prepared the list of names of tropical cyclones in the Bay of Bengal and the Arabian Sea, to be given from the September 2004 season.
• The name of each cyclone is picked from this list and cycles through each country’s suggestion.
  • For example, after Michaung (by Myanmar), the next five cyclones will be called ‘Remal’ (Oman), ‘Asna’ (Pakistan), ‘Dana’ (Qatar), ‘Fengal’ (Saudi Arabia), and ‘Shakhti’ (Sri Lanka).

WHY DID CYCLONE MICHAUNG INTENSIFY?

• On December 4, the cyclonic storm intensified into a super-cyclonic storm. Such intensification events are a source of uncertainty in cyclone models because they alter the storm’s future course.
• Tropical cyclones are ‘engines’ that use a warm sea surface as ‘fuel’. This is why they form close to the equator (but seldom at the equator itself because the spinning force, called the Coriolis force, is lowest there).
• As air moves over such a warm sea, it also becomes warmer and laden with moisture, and begins to ascend. In the process, it becomes cooler, which condenses the vapour and forms clouds.
• Condensation releases heat, which makes the air lighter and causes it to ascend further. As it does, the surrounding air moves in underneath, creating the surface winds associated with cyclones.
• The intensification is also greater if the cyclone spends more time over the water before landfall, as Cyclone Michaung did off the coast of north Tamil Nadu.

GOVERNMENT INITIATIVES

Stormwater drainage system: The Tamil Nadu government is constructing a stormwater drainage system across Chennai and the city administration has claimed that the areas with the new drains escaped flooding. The Rs 4,500 crore project has been on since 2017 and by all accounts, nearly two-thirds of Chennai remains to be connected with the new network.

Flood Management Programme (FMP): Central Govt. has been providing financial assistance through a scheme called Flood Management Programme (FMP) since XIth Plan. The scheme since its inception has undergone several changes as per demands of states/UTs and also on account of various directions and policies of Govt.

Central Water Commission (CWC): The Government of India set up the Central Water Commission for achieving the goal of furthering and promoting measures of flood control, conservation and utilization of water resources throughout the country in the areas of beneficial uses, irrigation and hydropower generation, flood management and river conservation.

National Disaster Management Authority (NDMA): For prevention and mitigation effects of disasters including flood disasters and for undertaking a holistic, coordinated and prompt response to any disaster situation, the Government of India has set up a National Disaster Management Authority.

CONSEQUENCES OF THE INTENSIFICATION

Flooding: Heavy rainfall caused floods that submerged houses and halted communication services. At least 20 people have lost their lives.

Power outages: Several localities continue to be under water more than 48 hours after the rains abated, leading to power outages.

Shortages of essentials: There are shortages, including drinking water, milk and diesel.

Electrocutions: People are being electrocuted by loose cable wires.

Ineffective drainage system: The city’s drainage system is inadequate and needs to be improved.

Wetland encroachment: Construction projects on wetlands should be rethought.

Drinking water shortage: The city has a pressing drinking water shortage problem.

THE WAY FORWARD

Drainage revamp system: The suffering caused by the latest floods should push the state government to expedite the drainage revamp system.

Construction projects on wetlands:  After the 2015 floods, experts reasoned that planners should re-think construction projects on wetlands.

Create flood-resilient infrastructure: Design and build infrastructure, such as roads and buildings, to withstand flooding. This includes raising electrical panels, using flood-resistant materials, and installing backflow prevention devices.

Upgrade and expand drainage systems: This includes increasing the capacity of existing drainage channels, constructing new ones, and improving the efficiency of pumping stations.

CONCLUSION:

In the past five years, meteorological agencies have stepped up to the challenge of issuing timely cyclone alerts. City planners need to act now. A holistic approach combining drainage improvements, wetland preservation, and sustainable urban planning is key to bolstering flood resilience.

PREVIOUS YEAR QUESTION:

Q.1) Discuss the meaning of colour-coded weather warnings for cyclone prone areas given by Indian Meteorological Department. (2022)

Q.2) The frequency of urban floods due to high intensity rainfall is increasing over the years. Discussing the reasons for urban floods, highlight the mechanisms for preparedness to reduce the risk during such events. (2017)

MAINS PRACTICE QUESTION:

Q.1) In recent years, Tamil Nadu has been experiencing short-duration spells of intense rainfall, like in several parts of the country. What are the reasons for frequent floods in India? Suggest steps that need to be taken for proper flood management.

SOURCE: Express View on Chennai floods: A wake-up call for urban planners | The Indian Express