Landfall of a cyclone

What’s in today’s article?

• Why in news?
• What is landfall of a cyclone?
• What is the damage caused by a cyclone’s landfall?
• How long does a landfall last?
• Management of cyclones
• Steps taken by India for the management of cyclones

 

Why in news?

• On June 15, the landfall process of Cyclone Biparjoy started near Jakhau port in the state’s Kutch district and continued till midnight.

 

What is landfall of a cyclone?

• Landfall is the event of a tropical cyclone coming onto land after being over water. 
• As per the IMD, a tropical cyclone is said to have made a landfall when the center of the storm – or its eye – moves over the coast.
  • The "eye" of a cyclone is a region of relatively calm weather found at the center of the storm. 
  • It is a circular or oval-shaped area characterized by light winds, clear or partly cloudy skies, and decreased precipitation.
  • Within the eye, winds are light and variable, often with clear or only partially cloudy skies. 
  • The size of the eye can vary significantly, ranging from a few kilometers to over 50 kilometers (30 miles) in diameter in larger cyclones.
• During landfall, the outer bands of the storm may have already reached the coast, bringing strong winds, heavy rain, and storm surge. 
• Landfall marks the moment when the cyclone officially reaches the land.
  • A landfall should not be confused with a ‘direct hit’, which refers to a situation where the core of high winds (or eyewall) comes onshore but the centre of the storm may stay remain offshore.

 

What is the damage caused by a cyclone’s landfall?

• The damage caused by the landfall will depend on the severity of the cyclone – marked by the speed of its winds. 
• E.g., for Cyclone Biparjoy, classified by the IMD as a “very severe cyclonic storm”, the impact may include extensive damage to kutcha houses, partial disruption of power and communication lines, minor disruption of rail and road traffic, etc.

 

How long does a landfall last?

• Landfalls can last for a few hours, with their exact duration depending on the speed of the winds and the size of the storm system. 
  • E.g., Cyclone Biparjoy’s land process is expected to last around five to six hours, with the cyclone almost completely dissipating over approximately the next 24 hours.
• Cyclones lose their intensity once they move over land because of sharp reduction of moisture supply and increase in surface friction. 
• This means that while landfalls are often the most devastating moments of cyclones, they also mark the beginning of its end.

 

Management of cyclones

• The National Disaster Management Authority (NDMA) in India outlines several key components for the management of cyclones. These components include:
• Risk Assessment and Early Warning Systems
  • Conducting risk assessments to identify vulnerable areas, populations, and infrastructure.
  • Developing and maintaining robust early warning systems that provide timely and accurate information about approaching cyclones.
  • Disseminating warnings and advisories through multiple channels to reach the affected communities and stakeholders.
• Preparedness and Planning
  • Developing and regularly updating cyclone-specific disaster management plans at national, state, and local levels.
  • Identifying and establishing cyclone shelters, evacuation routes, and assembly points in vulnerable areas.
  • Stockpiling and pre-positioning essential emergency supplies such as food, water, medical provisions, and relief materials.
  • Conducting regular drills, exercises etc.
• Mitigation measures
  • Strict adherence to building Codes and Regulations in cyclone-prone areas
  • Coastal Zone Management: 
    • Implementation of effective coastal zone management plans to regulate development activities along vulnerable coastlines.
    • It also includes Mangrove Plantation, development of bio-shields, shelterbelt plantation, coastal flood management etc.
  • Infrastructure Development: 
    • Regular maintenance and strengthening of critical infrastructure such as roads, bridges, power lines, and communication networks.
• Response and Coordination
  • Activating emergency response mechanisms at all levels of governance, including the National, State, and District Disaster Management Authorities.
  • Coordinating with various stakeholders including NGOs
  • Mobilizing resources, including manpower, equipment, and relief supplies, for rescue, evacuation, medical assistance, and other response operations.
  • Establishing emergency operation centers and coordination cells to facilitate real-time information sharing and decision-making.
• Evacuation and Shelter Management
  • Ensuring the availability and readiness of cyclone shelters and evacuation centers, equipped with basic amenities and facilities.
  • Organizing systematic and orderly evacuations, prioritizing the safety and well-being of vulnerable groups such as the elderly, children, and people with disabilities.
• Recovery and Rehabilitation
  • Undertaking post-cyclone damage assessments to ascertain the extent of destruction and prioritize recovery efforts.
  • Providing immediate relief assistance to affected communities, including shelter, food, water, healthcare, and sanitation facilities.
  • Implementing medium- and long-term rehabilitation and reconstruction plans to restore infrastructure, livelihoods, and community resilience.
  • Promoting sustainable development practices and resilient infrastructure designs to minimize future vulnerability.

 

Steps taken by India for the management of cyclones

• National Cyclone Risk Mitigation Project (NCRMP): 
  • Launched by the MHA, this project aims to reduce the vulnerability of coastal communities and infrastructure to cyclones and storm surges.
  • It focuses on capacity building, early warning systems, cyclone shelters, evacuation planning, and community awareness.
• IMD’s Colour Coding of Cyclones
  • Four colours - Green, Yellow, Orange, and Red – are used by IMD to make people aware about the severity of cyclones.
• Integrated Coastal Zone Management (ICZM) Project 
• Coastal Regulation Zones (CRZ)
• Other general steps taken:
  • National Disaster Response Force (NDRF)
  • National Disaster Management Plan (NDMP)
  • National Institute of Disaster Management (NIDM)
  • State Disaster Management Authorities (SDMAs)

 

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Q1) What is a cyclone?

A cyclone is a large-scale weather system characterized by low atmospheric pressure at its center and rotating winds that spiral inward toward the center. Cyclones are also known as hurricanes or typhoons, depending on the region in which they occur. In general, cyclones form over warm ocean waters in tropical and subtropical regions. They are fueled by the evaporation of water from the ocean's surface, which provides the energy needed for their formation and intensification. As the warm, moist air rises, it creates an area of low pressure at the surface, and air from surrounding areas rushes in to fill the void. The rotation of the Earth causes the incoming air to rotate, giving the cyclone its characteristic circular motion.

 

Q2) What is National Disaster Response Force (NDRF)?

The National Disaster Response Force (NDRF) is a specialized disaster response and rescue force in India. It was established in 2006 under the Disaster Management Act, with the primary objective of responding to natural and man-made disasters in the country. The NDRF operates under the jurisdiction of the Ministry of Home Affairs and functions as a specialized force for disaster response, relief, and rescue operations. Its primary role is to provide prompt assistance to the affected population during disasters and coordinate relief efforts with other agencies.

 

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Source: Cyclone Biparjoy: What is the ‘landfall’ of a cyclone? | National Disaster Management Guidelines | NDMA | GSDMA | Indian Express