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| Last Updated:: 03/04/2024


Natural disasters are consequences of a natural hazard like an earthquake, landslide, cyclone, flood, tsunami which affects human activities. Human vulnerability to disasters is increased by poverty and the risk potential for disasters. A lack of planning, preparedness and appropriate emergency management systems can lead to devastating to human, animal, economic, and environmental. The impact of natural disasters has been reduced by increasing preparedness for them, and when a disaster occurs, rapidly and effectively assessing the impact of same.
Natural Disaster
natural disaster is "the negative impact following an actual occurrence of natural hazard in the event that it significantly harms a community”. A natural disaster can cause loss of life or damage property and typically leaves some economic damage in its wake. The severity of the damage depends on the affected population's resilience and on the infrastructure available. 
Examples of natural hazards include
      Avalanche,  coastal flooding, cold wave, drought, earthquake, hail, heat wave, hurricane (tropical cyclone), icestorm, landslide, lightning,riverine flooding, strong wind, tornado, tsunami, volcanic activity, wildfire, winter weather.
Manmade or Technological Disaster
A technological disaster is an event caused by a malfunction of a technological structure and some human error in controlling or handling the technology. Technological disasters can be considered a man-made disaster meaning there is an "identifiable cause" characteristic. Chemical, nuclear and radiological hazards, as well as transport hazards are defined as those "originate from technological or industrial conditions, dangerous procedures, infrastructure failures or specific human activities. 
Tamil Nadu State is not an exception to environmental hazards. It is highly prone to multiple disasters as the state is frequented by various natural calamities with different intensities. The vulnerability of the coastal community became exceedingly evident when Tsunami struck the southern coast of India. Besides Tsunami, the coastal community faces disasters like cyclone and floods periodically. Communities living in other hazard prone zones and hilly regions of the State face threats from landslides, earthquakes and floods. Urban flooding is also becoming a growing concern in the State.
Environmental Disasters in Tamil Nadu 
A number of natural and man-made hazards have affected the state in the recent past. Damages caused due to disasters were mounted to a larger extent. It has created huge loss to human life and affected normalcy of the state at many intervals. 
Cyclone / Heavy Rainfall Vulnerability     
The geographical setting of Tamil Nadu makes the state vulnerable to natural disasters such as cyclones, floods and earthquake-induced tsunami.  About 8% of the state is affected by five to six cyclones every year, of which two to three are severe.  Cyclonic activities on the east coast are more severe than on the west coast, and occur mainly during October-December.  On an average, the State encounters one or two cyclonic events during the Northeast monsoon period. 
Even during the non-cyclonic phase, the State receives sudden and very heavy spells of incessant rains during the formation of low pressure/deep depressions in the Bay of Bengal.  The low pressure/deep depressions so formed cause flooding and inundation in the vulnerable areas.  Of late extreme weather events are resulting in extremely heavy rains, way beyond the carrying capacity of the river systems and the drainage system, disrupting normalcy.  Some of the cyclonic storms are accompanied by gale winds gushing even beyond 140 Kmph, wrecking havoc on the public infrastructure including power infrastructure and causing loss of lives and damages to housing and agricultural properties. 
Coastal Vulnerability
 There are 13 coastal Districts, 25 coastal blocks and 561 fishing villages in the coastal areas.  The coastal ecosystems are now encountering problems ranging from pollution, siltation and coastal erosion to that of flooding, saltwater intrusion and storm surges.  The Tamil Nadu coast comprises of the Coromandel Coast from Pulicat Lake in the north to Point Calimere in the south, and the Gulf of Mannar, which extends up to the tip of Kanyakumari, which is the southernmost point of the Indian Peninsula.  The Cyclones and the Tsunami of 2004 had a devastating impact along the coast.High Erosion Zones along the Tamil Nadu coast include the districts of Kanyakumari, Tirunelveli, parts of Tuticorin, Ramanathapuram, Pudukkotai, Thanjavur, Thiruvarur, Nagapattinam, Cuddalore, Villupuram, Kancheepuram, Chennai and Thiruvallur. The state has prepared shoreline change maps for each district
High Wind Vulnerability
The Districts of Nagapattinam, Thanjavur, Madurai, Salem, Tiruchirappalli, Kancheepuram, Rameswaram, Ramanadhapuram and Chennai are vulnerable to high wind velocity. Tamil Nadu falls into three categories of the wind zones: 
ü VeryHigh risk zone - 76-117 Km/Hour
ü High damage risk zone - 63-74 Km/Hour
ü Moderate damage risk zone - 31-39 KM/Hour 
Storm Surge Vulnerability
Storm surge varies from 3 meters to 11 meters in the Tamil Nadu coast. The Southern parts of Thanjavur, Pudukkottai, Ramanathapuram, Thoothukudi, Tirunelveli and Kanyakumari have experienced storm surges exceeding 6m above the concurrent sea level. The northern regions of Thanjavur, Cuddalore, and Chennai have lower storm surge heights of around 3 meters.
Drought Vulnerability
Low rainfall coupled with the erratic behavior of the monsoon in the state makes Tamil Nadu the most vulnerable to drought.  Drought can have a devastating impact and can affect a large population. Drought variability has a direct and significant impact on food production and the overall economy.  Drought is more recurrent during June to September months in Tamil Nadu.  Traditionally, the districts which are severely prone to drought hazard are Dharmapuri, Madurai, Coimbatore, Ramanathapuram, Salem, Tiruchirapalli, Tirunelveli and Kanyakumari. But during 2017, Tamil Nadu experienced severest drought unheard so far that adversely affected the agricultural and drinking water sectors.
Land Slides Vulnerability
The landslide hazard zonation atlas of India published by Building Materials and Technology Promotion Council (BMTPC), Government of India, categorized the Nilgiris district of Tamil Nadu state as one of the severe to very high landslide hazard prone areas of India. Landslides occur during the seasonal rains in the Nilgiris Hill Range and some of the major ones that have occurred are the Runnymede landslide, the Glenmore landslide, the Coonoor landslide, the Karadipallam landslide, Megamalai landslide and the Marapalam landslide. Besides Nilgiris, other districts in the state that have had the problem of the landslide are Salem, Erode, Coimbatore, Vellore, Dindigul (Kodaikanal hills) and Theni. The Geo Technical Cell established by Government in The Nilgris District has studied the Landslide aspects exhaustively through Institute of Remote Sensing Anna University and potentially vulnerable Watersheds have been identified for treatment.  

Tsunami Vulnerability 

Tsunami is one among the catastrophic tectonic Phenomena of the crustal part of the earth created mostly by a submarine earthquake. They occur at plate boundaries due to interaction of two convergent plates resulting sub-duction of an oceanic plate at depth of tens of kilometers in the asthenosphere. A tsunami can cause damage up to a few thousand kilometers from its origin, so there might be several hours between its creation and impact on a coast. Tsunami that struck the Tamil Nadu coastal areas in December 2004 resulted in large-scale damage to life and property.  
Heat Wave Vulnerability
A Heat Wave is a period of abnormal high temperatures, more than the normal maximum temperature that occurs during the (Hot weather) summer season. Heat Waves typically occur between March and June. The extreme temperatures and resultant atmospheric conditions adversely affect people living in these regions as they cause physiological stress, sometimes resulting in death. Some of the districts in Tamil Nadu that have witnessed impact of heat waves are Vellore, Thiruvannamalai, Krishangiri, Dharmapuri, Salem, Namakkal, Tiruppur, Coimbatore, Erode, Karur, Tiruchirapalli, Ariyalur, Perambalur, Sivaganga, Virudhunagar, Theni, Dindigul and Madurai.
Seismic Vulnerability                                                            
Tamil Nadu is one of the 13 identified seismo-tectonic zones of Peninsular India. The East – West Cauvery fault Tirukkovilur – Pondicherry fault, Vaigai River fault and North-Southern trending Comorin – Point Calimere Fault and Rajapatnam – Devipatnam Fault are some of them which run close to the urban centers like Coimbatore, Madurai, Nagapattinam, Thanjavur, and Pondicherry and thus make the state vulnerable to tremors and earthquakes geologically.
Tamil Nadu experienced moderate earthquakes in the past earthquake history of 200 years as is evident from the published literature. Twelve earthquakes of M > 5.0 are known to have occurred in the State so far. The latest Seismic zoning map of Bureau of Indian Standards classifies Tamil Nadu into two categories - Zone II and Zone III (representing an area of 73% and 27% respectively), which is under Low risk (upto magnitute 4.9) and Moderate risk (upto Magnitude 6.9) respectively including many districts in the state namely Chennai, Thiruvallur, Vellore, Coimbatore, Dharmapuri, Salem, Tirunelveli, Kanyakumari and The Nilgiris. Chennai, the state capital and the major cities Coimbatore and Salem fall under seismic zone III. 

Fire Risk and Explosives

      Tamil Nadu is vulnerable to fire risk disasters and some of the districts fall in the very high risk and high-risk categories. Districts have been analyzed based on fire risk ranking by specialized groups and the analysis reveals that six districts namely Chennai, Coimbatore, Dindigul, Kancheepuram, Madurai, and Tiruvallur are under the ‘very high risk’ category, Cuddalore, Namakkal, Thanjavur, Tuticorin, Tiruchirapalli, Tirunelveli, Tiruppur, Vellore and Virudhunagar in the ‘high risk’ category. The analysis was borne out of assessing the population density, residential built-up area and Industrial areas in these districts. Forest fires are also a major problem in Nilgiris, Salem, Theni, and Dharmapuri due to acute drought conditions, lightning and sometimes induced by human activities.
Chemical, Biological, Radiological and Nuclear (CBRN)
Tamil Nadu also has a number of Industries which are vulnerable to natural as well as man-made disasters. There are 123 MAH units in Tamil Nadu falling under this category because of the storage of highly inflammable petroleum products in large quantities. There are underground pipelines carrying petroleum products across the state apart from tankers and railways carrying chemicals which are potentially hazardous. The three major types of hazards possible with chemical emergencies are fires, explosions, and toxic releases that could affect the population and the environment. Kancheepuram, Tiruvallur, Cuddalore, Madurai, Vellore, Thoothukudi, Thanjavur and Ramnathapuram districts have industries that are dealing with potentially hazardous materials and hence have the vulnerability factor. 
Nuclear Plants possible Radiation Vulnerability
Tamil Nadu has two Nuclear power plants namely, Madras Atomic Power Station at Kalpakkam two units of 220 MW each and the Koodankulam nuclear power station with an 1000 MW unit in Tirunelveli district.Kudankulam has one 1000 MWe reactor operating and another 1000 MWe reactor is under commissioning.  
Disaster Management – Tamil Nadu
 The State of Tamil Nadu is located in the vulnerable part of the Indian Peninsula and subject to climate and geological disasters - cyclone, flood, earthquakes, tsunami and drought to varying degrees. The 14 coastal Districts, viz., Chennai, Kancheepuram, Tiruvallur, Cuddalore, Villupuram, Thanjavur, Tiruvarur, Nagapattinam, Mayiladuthurai, Pudukottai, Ramanathapuram, Thoothukudi, Tirunelveli and Kanniyakumari are highly vulnerable and affected by the trough and depression formed in the Bay of Bengal and Indian Ocean during South-West and North-East monsoon periods. The geographic setting of the State makes it vulnerable also to lightning, landslide, forest fires, sea erosion etc., Management of these disasters is highly complex and poses serious challenges in all phases of disaster viz., 33 Preparedness, Response, Recovery and Risk Mitigation.  
Relief and Rehabilitation Activities:
During and after any disaster in the State, the department provides relief. Post disaster periodic reviews are made and arrangements made to swiftly disburse relief. 
Preparation and Updating of Disaster Management (DM) Plans:
  As part of the strengthening of disaster management information systems in the State, it is essential to systematically develop district disaster management plans that will be instrumental for effective preparedness, response and mitigation of disaster risks in the respective districts. The existing plans will be reviewed and updated during the said process. The exercise will be undertaken in all districts. The same exercise will be undertaken to update State Disaster Management plan. Regular mock drills based on the Disaster Management plans are being planned in the State and Districts. 
Strengthening of Emergency Operation Centers in the State/Districts:
Sensing the need to create an effective emergency operation center, it is proposed to provide all essential facilities to promote effective coordination between stakeholders and enhance efficiency of emergency management operations. Transport facilities, communication systems and office requirements will be provided for, under this component. It is being proposed to strengthen the emergency management systems at the Sub-divisional and Taluk levels also. Towards this end, it is proposed to provide emergency equipment to the Sub-divisional/ Taluk offices, which will be used during times of emergencies. It is also proposed to form State Disaster Response Force (SDRF) by training a Battalion of Tamil Nadu Special Police. The training will be imparted by National Disaster Response force. 
Strengthening of Emergency Response at Hospitals:
Hospitals are one of the crucial players during emergencies and hence it is proposed to strengthen their emergency response capacities. Towards this end, it is proposed to support major Government hospitals in the State to develop a disaster management plan, to handle emergency, situations effectively.  The proposal also envisages training of hospital personnel and organizing mock drills in the premises based on the plan. 
Development of Training Modules and Curriculum at State owned Training Institutes:
The Government departments in the State have been organizing a series of trainings and workshops for their staff through their training units/institutes. Subjects pertaining to their respective disciplines are dealt with during these programmes. Some of these departments are active stakeholders during disaster/ emergency periods and the services of their personnel are expected to be vital for effective management of disasters/ emergencies. To enhance their understanding on the relevance of disaster/emergency management to their domain of working, the Revenue Administration, Disaster Management and Mitigation department proposes to jointly work with other departments like Agriculture, Rural Development, Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB), Tamil Nadu Water Supply and Drainage Board (TWAD Board), Water Resource Organization (Irrigation), Health, Electricity and Fire and Rescue Services etc., to develop training modules and curricula on disaster management with specific reference to their respective domains. The State Administrative Training Institute (ATI) will be the focal organization to develop individual training modules jointly with the respective departments/training institutes. NCC cadets will be given one week training in selected locations for preparedness and demand driven services.  
Conduct of Trainings and Workshops:
            In continuation of the development of training module and curriculum, it is proposed to support the above said training institutes to integrate the said modules in their ongoing trainings/workshops. 
Assessment of Hazard, Vulnerability and Risk in vulnerable districts:
Towards developing an effective disaster mitigation plan, it is essential to systematically assess the nature of the hazard, the vulnerabilities that increase the disaster risks and the possible impacts that the disaster could create on lives, livelihoods and assets. Towards this end, it is proposed to undertake this study in multi-hazard prone districts in the State that are prone to wind, cyclone and floods. The said assessment of hazard, vulnerability and risk will be undertaken to develop a disaster risk mitigation plan.  
Risk Reduction in the State
  • It is proposed to revisit existing “Building By-laws” to make necessary amendments to ensure safe construction especially in disaster prone areas.
  • Recommendations will be made to undertake disaster resistant constructions under IAY (Indira Awaas Yojana) scheme.
  • Recommendations will be made to lay underground electric / communication cables in cyclone prone coastal areas.
  • It is proposed to develop bio-shield along the coastal areas, which will serve as wind brakes/ shelterbelts to mitigate damages due to strong winds. Farmers will be encouraged to take up the said activity.
  • Special Insurance for cattle and crops in disaster prone areas will be provided. Establishment of a State Disaster Management Training Center is to be proposed.
        The State has been a victim of natural calamities such as cyclones, tsunamis, and floods in some years and severe drought in certain years.  According to the National Institute of Disaster Management, 13 districts of Tamil Nadu are vulnerable to high or very high cyclonic impact and flooding. There are at least seven districts in the state that are regularly impacted by drought conditions. A comprehensive plan for reducing the impact of the natural disasters and creating a dynamic response mechanism to natural calamities is part of Vision Tamil Nadu 2023. Environmental measures such as mangrove plantations in coastal areas prone to cyclonic storms will be developed. Mechanism will be developed for relief measures such as disaster management group will be formed at each taluk. As the State of Tamil Nadu often encounters natural calamities, a dedicated State Disaster Rescue Force will be formed to respond expeditiously and effectively. This will be on the pattern of the National Disaster Relief Force, trained in rapid rescue operations. 
The Regional Integrated Multi- Hazard Early Warning System for Africa and Asia (RIMES) is an international and intergovernmental institution, owned and managed by its Member States, for the generation and application of early warning information. The Mission of RIMES is building capacity and providing actionable warning information towards forearmed, forewarned and resilient communities. RIMES provide regional early warning services and builds capacity of its Member States in the end to- end early warning of tsunami and hydro meteorological hazards. It is essential to recognize the possible influences of weather and climate at all time scales – from days to decades, and plan for minimizing its impact and maximizing its opportunities to achieve the development trajectories envisioned in the Twelfth Five Year Plan and the Vision Tamil Nadu 2023, through a Climate Risk Management framework. 
In Tamil Nadu, weather risks are transmitted directly or indirectly to Primary, Secondary and Tertiary sectors; hence incorporating 5 to 10 days forecast system could be useful to reduce the direct losses and indirect losses through various climate/weather information scales. There is considerable capacity building required to use the robust risk communication ability to accept and adapt the probable forecast information in a risk management framework. Therefore, the services of RIMES in Climate Risk Management shall be utilized in the development planning processes in Tamil Nadu. 
               Disaster Management has to be a multidisciplinary and pro-active approach. Besides various measures for putting in place institutional and policy framework, disaster prevention, mitigation and preparedness enunciated in this plan and initiatives being taken by the environment department also have a key role to play in achieving our goal of moving together, towards a safer Environment. The message being put across is that, in order to move towards safer and sustainable national development, development projects should be sensitive towards disaster mitigation. Our mission is vulnerability reduction to all types of Environmental hazards, be it natural or manmade. Our vision is to build a safer and secure environment through sustained collective effort, synergy of national capacities and people’s participation.
Tamil Nadu State Disaster Management Authority Web Portal -
Revenue and Disaster Management Policy note 2022 – 2023 -