NDMA Guidelines of Management of Cyclones

India’s coastal regions in the North Indian Ocean Basin are extremely vulnerable to cyclones and associated hazards such as storm tides.

Storm Tides

Storm Tides refers to the combined effects of storm surge and astronomical tide. Storm surge is the an abnormal rise in the level of water along a shore, primarily as a result of the high winds and low pressures generated with tropical cyclones; generally affects only coastal areas but may intrude some distance inland. Astronomical tides refers to tidal levels and character which would result from gravitational effects, e.g., of the Earth, Sun and Moon, without any atmospheric influences.

About 8% of the area in the country is prone to cyclone-related disasters. Recurring cyclones account for large number of deaths, loss of livelihood opportunities, loss of public and private property and severe damage to infrastructure, thus seriously reversing developmental gains at regular intervals.

Reasons for Cyclone Vulnerability

There are several reasons for this vulnerability. India has a long coastline of around 7,516 km, its coastal terrain is flat and continental shelf is shallow. Further, most coastal cities have high population density. Although the frequency of Tropical Cyclones (TCs) in the NIO covering the Bay of Bengal and the Arabian Sea is the least in the world (7% of the global total), their impact on the east coast of India as well as the Bangladesh coast is relatively more devastating. This is evident from the fact that in the last 270 years, 21 of the 23 major cyclones (with a loss of about 10,000 lives or more) worldwide occurred over the area surrounding the Indian subcontinent (India and Bangladesh). This is primarily due to the serious storm tide effect in the area.

Affected States and UTs

Thirteen coastal states and Union Territories (UTs) in the country, encompassing 84 coastal districts, are affected by tropical cyclones. Out of them, the most vulnerable on East coast are four states viz. Tamil Nadu, Andhra Pradesh, Orissa and West Bengal and one UT (Puducherry) while on west coast is one state Gujarat.

National Cyclone Risk Mitigation Project

The National Cyclone Risk Mitigation Project (NCRMP), to be implemented with financial assistance from the World Bank, is envisaged to have four major components:

  • Component A: Improvement of early warning dissemination system by strengthening the Last Mile Connectivity (LMC) of cyclone warnings and advisories.
  • Component B: Cyclone risk mitigation investments.
  • Component C: Technical assistance for hazard risk management and capacity-building.
  • Component D: Project management and institutional support.

These components are highly interdependent and have to be implemented in a coherent manner. The planned framework of activities under this project provides end-to-end solutions for effective Cyclone Disaster Management (CDM) in all the 13 coastal states and UTs.

National Guidelines of Management of Cyclones

The NDMA had come up with its National Guidelines of Management of Cyclones in 2008. The basic premise of these guidelines is that the mitigation has to be multi-sectoral. Salient points in these guidelines are as follows:

Early Warning System

Government would establish a state-of-the-art cyclone EWS involving observations, predictions, warnings and customised local-scale advice for decision-makers (national/state/district level) for managing the impact of cyclones.

Aircraft Probing of Cyclone (APC) facility

The government would commission an Aircraft Probing of Cyclone (APC) facility for India with a combination of manned aircraft and high altitude Unmanned Aerial Vehicles (UAV) which can effectively fill the critical observational data gaps in the case of cyclones over the Bay of Bengal and the Arabian Sea to a great extent. An actual flight by an aircraft into and around the tropical cyclone during various stages of its development and movement can provide invaluable data for studying and understanding the structure and movement of a cyclone, thus reducing track and intensity prediction errors significantly.

National Disaster Communication Infrastructure (NDCI)

Government would commission National Disaster Communication Infrastructure (NDCI) at the NDMA/MHA, State Disaster Management Authorities (SDMAs) of coastal states/UTs and District Disaster Management Authorities (DDMAs) of the 84 coastal districts vulnerable to cyclones with the adoption of state-of-the-art operational infrastructure covering the following:

  • High End Computing (scalable 30–50 Teraflops peak performance), Storage (800 Terabytes) and Communication Network (Gigabit Ethernet) Infrastructure;
  • 3-D Virtual Reality Visual Studio;
  • Centralised Comprehensive Databank for Cyclone Risk Management with nodes in various coastal states over a fail-safe communication backbone between the OCs (Operation Centres) of NDMA, SDMAs and DDMAs (for Information and Data Fusion involving collating, analysing, interpreting, translating and monitoring of early warnings from line departments based on state-of-the-art scientific and technological know-how); and
  • Comprehensive state-of-the-art OC for effective coordination of Disaster Response Actions at the state and local levels.
Expanding the warning dissemination outreach

Government would be expanding the warning dissemination outreach by using the services of Direct-To-Home (DTH) transmission in remote and rural areas (Panchayats) which cannot be otherwise covered, to introduce weather channel and broadcast cyclone warnings from high-power coastal radio stations including the use of satellite radio service like World Space, Ham radios, community radio and VHF network.

Other Actions
  • Structural safety of lifeline infrastructure in coastal areas
  • Establishing a robust system of locating multi-purpose cyclone shelters and cattle mounds
  • Ensuring cyclone resistant design standards are incorporated in the rural/ urban housing schemes in coastal areas
  • Building all-weather road links to all coastal habitations, between habitations and cyclone shelters/cattle mounds
  • Maintaining the full designed carrying capacity of main drains and canals along with feeder primary/secondary/ tertiary channels, creating additional flood flow canals in frequently inundated areas
  • Construction of saline embankments to prevent ingress of saline water associated with cyclonic storm surge
  • Encouraging public-private partnership with corporate/trusts.
  • Mapping and delineation of coastal wetlands, patches of mangroves and shelterbelts, identification of potential zones for expanding bio-shield spread based on remote sensing tools.
  • Regulating infrastructure and development activities in coastal zones.
  • Monitoring of water quality as well as the carrying and assimilative capacities of open waters with institutionalised remedial measures.
  • Developing Integrated Coastal Zone Management (ICZM) frameworks for addressing the sustainability and optimal utilisation of coastal resources as also cyclone impact minimisation plans.
  • Evolving eco-system restoration plans for degraded ecological zones.
  • Developing delta water management and freshwater recharge/management options.
  • Coastal bio-shields spread, preservation and restoration/ regeneration plans.
  • Implementing coastal flood zoning, flood plain development and flood inundation management and regulatory plans.
  • Groundwater development and augmentation of freshwater requirement in coastal urban centres.
  • Development of Aquaculture Parks in the identified potential zones.
  • Setting up of an exclusive eco-system monitoring network to study the impact of changing climate.
  • Developing integrated hazard mitigation framework taking into account cyclone and associated storm surge, wind hazard, rainfall-runoff, river flood and Geographical Information System (GIS) models for estimating possible areas of inundation along with the depth of inundation (levels), possible damage to infrastructure, crops, houses, etc., evaluating not only the vulnerability but also the changing profile of vulnerability from time to time.
  • Integrate ongoing efforts of the Survey of India, Department of Space under National Spatial Data Infrastructure, National Database for Emergency Management and MoEF initiatives for speedy completion of digital spatial data generation to cover 84 coastal districts that are vulnerable to cyclones, for evolving holistic cyclone risk reduction strategies on priority. High resolution (at least 0.5 m interval) coastal Digital Elevation Models (DEMs) are to be developed for micro-scale delineation of cyclone risk, hazard and vulnerability.