DIFFERENT DISASTERS AND THEIR MANAGEMENT MEASURES Study Materials

Landslides

Landslides, Land Subsidence and Avalanches

• Landslides refer to the downward movement of rocks, debris, or soil along mountain slopes or riverbanks.

• These movements can be gradual, but sudden and unexpected sliding may also occur.

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Landslides often coincide with natural disasters such as earthquakes, floods, and volcanic eruptions.

• In some cases, prolonged heavy rainfall triggers significant landslides that obstruct river flow for an extended period. When these blockages give way, they can cause severe destruction to downstream settlements.

• Landslides occur due to gravitational force, leading to both downward and outward displacement of slope materials.

• India's hilly regions, particularly the Himalayas and the Western Ghats, are highly susceptible to landslides.

• The Himalayan mountain range consists of young, geologically unstable formations, often resulting in massive landslides, such as the Malpa landslide of 1998.

• On the other hand, the Western Ghats and Nilgiri Hills are geologically stable but have elevated plateau edges influenced by neotectonic activity. Landslides in these regions are typically surface- level events that do not disturb the bedrock but occur mostly during monsoons, impacting the densely populated areas more severely.

• It is estimated that the Himalayan region accounts for 30% of the world's landslides. In the Nilgiris, heavy rainfall in 1978 led to severe landslides. Overall, landslides impact approximately 15% of India's total land area.

• Land Subsidence: It refers to the vertically downward movement or sinking of earth's surface, gradually or suddenly, caused by natural or man-made reasons like removal of water, oil or natural resources, earthquakes, soil erosion, soil compaction etc. e.g. 2023 Joshimath disaster.

• The regional variation in the incidences of landslides at national level can be seen in the following table.

    Map: Landslide prone areas of India    

Causes of landslides

• Intense Rainfall: One of the primary triggers of landslides is heavy rainfall.

• Loss of Vegetation Cover: Deforestation is another significant factor contributing to landslides. Trees, shrubs and grasses help bind soil particles together, maintaining stability. When trees are cut down, mountain slopes lose their protective layer, allowing rainwater to flow rapidly and uncontrollably, increasing the risk of landslides.

• Seismic Activity and Volcanic Eruptions: Earthquakes are frequent in the Himalayan region, causing tremors that destabilize mountains, leading to rockfalls and landslides. Similarly, volcanic eruptions can trigger landslides in mountainous areas.

• Road Construction: Infrastructure development in mountainous regions often requires road construction, which involves removing large amounts of rock and debris. This process weakens the natural rock structure and alters slope angles, making landslides more likely.

• Shifting Cultivation: In northeastern India, the practice of shifting agriculture has contributed to a rise in both the frequency and intensity of landslides.

• Urbanization and Tourism Development: The growing population and expanding tourism industry have led to increased construction of houses, hotels, and other buildings. The excavation and accumulation of construction debris further destabilize slopes, triggering landslides.

Impact of landslide

• Degrading of environment: Landslides are degrading the environment of mountains. Natural beauty is diminishing slowly and slowly.

• Sources of water are drying up.

• Flooding in rivers is increasing.

• Roads are blocked.

• Life and property are lost.

• The grasses of industrial importance should also be planted so that there is some economic return to the farmers as well.

Use the Surface Vegetative Cover to protect the land from raindrop’s beating action, bind the soil particles and decrease the velocity of flowing water.

Natural Disasters Cyclone

Natural Disasters: Cyclone

Cyclones occur due to atmospheric disturbances around a low-pressure zone, characterized by rapid and often destructive air circulation.

They are typically accompanied by intense storms and severe weather conditions. In the Northern Hemisphere, air moves inward in an anticlockwise direction, whereas in the Southern Hemisphere, it circulates clockwise.

Cyclones are categorized into two types: (i) extra-tropical cyclones, also known as temperate cyclones, and (ii) tropical cyclones.

Tropical cyclones result from interactions between the ocean and atmosphere, fueled by the sea's heat and influenced by easterly trade winds, temperate

westerlies, high planetary winds, and their own powerful energy.

Cyclones forming in the region between the Tropic of Cancer and the Tropic of Capricorn are termed tropical cyclones. These are large-scale weather systems developing over tropical or subtropical waters, leading to organized surface wind circulation.

Extra-tropical cyclones, on the other hand, develop in temperate and high-latitude regions, though some may originate from Polar Regions.

Indian Context

The Indian subcontinent is one of the worst affected regions in the world.

Map : cyclone prone areas in India

• Cyclones typically occur during two distinct seasons: the pre-monsoon period (May–June) and the post- monsoon period (October–November).

Their impact is mainly restricted to coastal districts, with the most severe destruction occurring within 100 km of the cyclone's center and along both sides of its path. The majority of casualties result from coastal flooding caused by tidal waves, storm surges, and heavy rainfall.

The Indian subcontinent, with an extensive coastline of 8,041 kilometers, is vulnerable to approximately 10% of the world’s tropical cyclones.

Around 71% of the cyclone-prone areas are spread across ten states—Gujarat, Maharashtra, Goa, Karnataka, Kerala, Tamil Nadu, Puducherry, Andhra Pradesh, Odisha, and West Bengal. Additionally, the Andaman and Nicobar Islands, as well as Lakshadweep, are also highly susceptible to cyclones.

A significant number of cyclones originate over the Bay of Bengal and primarily impact India's eastern coastline.

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On average, five to six tropical cyclones form annually, with two to three intensifying into severe storms. The Bay of Bengal experiences more cyclones than the Arabian Sea, with an approximate ratio of 4:1.

Some Do's and Don'ts Before, During and After the Cyclone

• Listen to the radio.

• Keep time for safety.

• When the storm strikes:

• Stay in the house and take shelter in the stronger portion of your house.

• Listen to the radio and follow instructions.

• Open windows of the safe portion of the house if the roof begins to lift.

• Find cyclone shelter if you are in open at the hitting time of the cyclone.

• Do not go out. Cyclone often generates large surges in these oceans or lakes.

• Impact of Cyclones

• Cyclones are characterized by their destructive potential to damage structures such as houses, lifeline infrastructure such as power and communication towers, hospitals, food storage facilities, roads, bridges, culverts, crops, etc., due to high velocity winds.

• Exceptionally heavy rainfall causes flooding. Storm surge inundates low-lying areas in the coastal areas resulting in loss of life and destruction of property, besides eroding beaches and embankments, destroying vegetation and reducing soil fertility.

• Such calamity leads to the evacuation and displacement of several marginalised people settled in the coastal areas,

which also has a huge effect on the livestock. Fisheries are also severely affected as the fish ponds are filled with silt and saline water, and their recovery takes time.

• The heavy rainfall also leads to drainage damage, which hampers the water supply and increases water sanitation problems. The drainage damage leads to an increase in the number of water-borne and vector diseases, such as Malaria, Dengue, Filaria and Kala- azar, among others, and the people who have been displaced and moved are unfortunately vulnerable to these diseases.

Cyclone Risk Mitigation Strategy

Cyclone Risk Mitigation Strategy Understanding Risk

• Upgrading observation networks, equipment, systems and technology

• Implementing land-and ocean-based observation systems

• Conducting research and studies to enhance forecasting accuracy

• Developing and maintaining a cyclone database for improved predictions

• Carrying out zoning and mapping of cyclone-prone regions

Monitoring coastal areas vulnerable to cyclones

• Conducting hazard risk and vulnerability assessments

• Ensuring effective dissemination of warnings, data, and information

Inter-Agency Coordination: Inter-agency collaboration plays a crucial role in strengthening disaster risk governance. Coordination is necessary between central and state agencies in various areas, including overall disaster management, emergency response, early warnings, information and data exchange, and the implementation of non-structural measures.

Investing in DRR–Structural Measures

• Identifying secure buildings and locations to serve as temporary shelters for evacuated residents and livestock from high-risk areas.

• Constructing multi-purpose cyclone shelters in coastal villages and settlements frequently affected by cyclones.

• Maintaining drainage systems and flood embankments to prevent waterlogging and mitigate flood risks.

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Ensuring adherence to relevant building codes for disaster-resistant construction.

• Incorporating cyclone-resistant features in the planning and execution of social housing projects.

• Implementing hazard-resistant construction methods, strengthening, and retrofitting critical infrastructure and lifeline structures.

• Cyclone Shelters: In densely populated coastal regions where large-scale evacuations are challenging, public buildings can serve as cyclone shelters. These structures should feature a blank façade with minimal openings facing prevailing winds. The shorter side of the building should be oriented toward the storm to minimize wind resistance.

• Promoting mangrove plantations and flood management initiatives.

• Ensuring the availability of emergency kits containing dry and packaged food.

• Using earth berms and green belts in front of buildings to reduce storm impact.

Investing in DRR–Non-Structural Measures

• Implementing ecologically sustainable land-use zoning while regulating activities such as aquaculture and groundwater extraction.

• Considering shoreline erosion and structural risks while monitoring shoreline changes to preserve natural barriers.

• Designating coastal zones for various purposes in accordance with Coastal Regulation Zone guidelines and the techno-legal framework of town and country planning regulations, ensuring proper enforcement and monitoring.

• Encouraging private sector participation in coastal management initiatives.

Capacity Development

• Conducting training and orientation programs for state government employees and key stakeholders, including civil society members, media professionals, elected representatives, and veterinary professionals, to support disaster-affected animals.

• Integrating disaster response, search and rescue operations into youth training programs, including village volunteers, to enhance the protection of animals impacted by disasters.

• Revising undergraduate engineering curricula to incorporate subjects related to cyclone hazard mitigation.

• Encouraging ministries and all States/UTs to organize and implement emergency drills regularly.

• Advancing skill development initiatives for multi- hazard-resistant construction in cyclone-prone regions, focusing on resilient housing and infrastructure such as wind- and water-resistant buildings, as well as structures on stilts.

• Incorporating gender sensitive and equitable approaches in capacity development covering all aspects of disaster management at the state, district, and local levels.

• Strengthen ability of communities to manage and cope with disasters based on a multi-hazard approach.

• Training for panchayat, SHG, NCC, NSS, youth, local community organizations.

• Awareness Generation:

• Carry out mass media campaigns

• Promote culture of disaster risk prevention, mitigation, and better risk management

• Promote attitude and behaviour change in the awareness campaigns

• Promote use of insurance/ risk transfer

• Promote Community Radio

• Strengthening network of civil society organizations for awareness generation about DRR and DM

Earthquake

Earthquake

An earthquake is a phenomenon that occurs without warning and involves violent shaking of the ground and everything over it. It results from the release of accumulated stress of the moving lithospheric or crustal plates.

The earth’s crust is divided into seven major plates, that are about 50 miles thick, which move slowly and continuously over the earth’s interior and several minor plates.

Earthquakes are tectonic in origin; that is the moving plates are responsible for the occurrence of violent shakes.

    Figure: Earthquakes    

Indian context:

• Around 59% of India's landmass is prone to earthquakes. The three most recent major earthquakes occurred in Gujarat in January 2001, Jammu and Kashmir in October 2005, and Sikkim in 2011.

The Himalayan Mountain range is the youngest fold mountain system globally and remains highly geologically active. Over the last 53 years, this region has experienced four earthquakes with magnitudes exceeding 8 on the Richter scale.

The peninsular region of India consists of a stable continental crust. Although it was previously regarded as having minimal seismic activity, the earthquake in Latur, Maharashtra, on September 30, 1993, with a magnitude of 6.4, led to significant loss of life and severe damage to infrastructure.

The Seismic Zoning Map

India is divided into four Seismic Zones:

• Zone V (Very High Damage Risk Zone): This includes the entire northeastern region, comprising the seven sister states, along with Kutch district, certain areas of Himachal Pradesh and Jammu & Kashmir, as well as the Andaman and Nicobar Islands.

• Zone IV (High Damage Risk Zone): This zone covers parts of the northern region, extending from Jammu & Kashmir to Himachal Pradesh. It also includes Delhi, portions of Haryana, and the Koyna region in Maharashtra.

• Zone III (Moderate Damage Risk Zone): This category encompasses a vast portion of India, stretching from the northern areas, including sections of Rajasthan, down to the southern regions along the Konkan coast, as well as parts of the eastern states.

• Zone II (Low Damage Risk Zone): These zones are adjacent, covering regions in Karnataka, Andhra Pradesh, Odisha, Madhya Pradesh, and Rajasthan, which are classified as low-risk earthquake-prone areas.

    Map: Seismic Zones of India    

IMPACT OF EARTHQUAKE

• Property Damage: Earthquakes can severely impact all types of structures, from small cottages to massive skyscrapers, often leading to partial or total destruction. Underground pipelines and railway tracks may suffer damage or breakage. River dams can collapse, causing catastrophic floods. The 1967 Koyna earthquake resulted in significant damage to the dam.

• Loss of Human Lives: Though earthquakes last only a few seconds, they can cause thousands of fatalities. The devastating earthquake in Gujarat on January 26, 2001, led to the deaths of over 25,000 people. The extent of property damage was immense and difficult to assess accurately.

• Alteration of River Courses: Earthquakes can obstruct river channels or alter their natural flow, leading to significant geographical changes.

• Tsunamis: Seismic activity can generate tsunamis, which cause destruction in coastal regions and even submerge

large ships. The 2004 tsunami near Sumatra, Indonesia, resulted in the loss of over 200,000 lives across Southeast Asia, India, and Sri Lanka.

• Mud Fountains: The intense force of an earthquake can push hot water and mud to the surface, creating fountains. The Bihar earthquake of 1934 caused cracks and fissures, covering agricultural fields in knee-deep mud and destroying crops.

• Cracks and Fissures: Tremors can lead to the formation of deep cracks in roads, railway tracks, and fields, rendering them unusable. The well-known San Andreas Fault was created during the San Francisco earthquake in California.

• Landslides and Avalanches: Earthquakes can trigger landslides and avalanches, further increasing destruction and endangering lives.

Challenges and Recommendations in Earthquake Disaster Management

Earthquake Risk Mitigation

Earthquake Risk Mitigation Understanding Disaster Risk

• Rapidly assess earthquake parameters immediately after

detection.

• Communicate and disseminate relevant information efficiently.

• Provide data on undersea earthquakes capable of triggering tsunamis in Indian coastal areas to the Indian National Centre for Ocean Information Services (INCOIS) for issuing tsunami alerts and warnings.

• Share seismic activity data with national and international scientific, academic, and research institutions.

• Conduct Earthquake Hazard and Risk Assessment (EHRA):

• Seismic Hazard Evaluation

• Seismic Zoning Classification

• Seismic Microzoning Studies

• Analyze vulnerability considering social, economic, ecological, gender, and equity aspects.

Inter-Agency Coordination

Inter-agency coordination is a key component of strengthening disaster risk governance. It is required among both central and state agencies in the field of Overall disaster governance, Response, Warnings, Information and data sharing and Non- structural measures.

Investing in Disaster Risk Reduction –Structural Measures

• Ensure the integration of earthquake-resistant features

in the planning and execution of social housing projects.

• Enforce adherence to applicable building codes and regulations.

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Implement strengthening measures and seismic retrofitting based on safety audit recommendations across all government departments, agencies, public utilities, educational institutions, and community halls.

• Collaborate with technical organizations for effective implementation.

Investing in DRR–Non-Structural Measures

• Establish appropriate bylaws for both rural and urban areas, implement model codes, and ensure strict adherence.

• Enforce rigorous compliance with building codes through relevant departments and agencies.

• Conduct safety audits for essential buildings and critical infrastructure.

• Ensure proper implementation, monitoring, enforcement, and compliance at the state level by public institutions, private entities, and individuals.

• Introduce a legal framework and institutional mechanism for licensing engineers.

• Encourage private sector involvement in disaster management initiatives.

Capacity Development

• Support national initiatives to develop a sufficient workforce trained in seismic safety across India.

• Provide training in search and rescue operations.

• Integrate disaster management aspects into undergraduate and professional education programs.

• Awareness Initiatives:

• Conduct mass media campaigns.

• Foster a culture of disaster risk prevention, mitigation, and effective risk management.

• Encourage behavioral and attitudinal changes through awareness programs and Information, Education, and Communication (IEC) initiatives.

• Promote the adoption of insurance and risk transfer mechanisms.

• Support the use of community radio for disaster awareness.

• Strengthen the network of civil society organizations to enhance awareness about Disaster Risk Reduction (DRR) and Disaster Management (DM).

• Provide information on the care and protection of animals affected by disasters.

• Collaborate on the planning and execution of emergency drills.

• Disseminate disaster-related documentation in local languages to improve accessibility.

• Integrate gender-sensitive and equitable strategies into capacity-building efforts at the state, district, and local levels for comprehensive disaster management.

• Community-Based Disaster Management:

• Enhance community resilience and preparedness through a multi-hazard approach.

• Conduct training programs for panchayats, Self- Help Groups (SHGs), National Cadet Corps (NCC), National Service Scheme (NSS), youth groups, and local community organizations to improve disaster

response capabilities.

Steps Taken for Earthquake Mitigation

• National Earthquake Risk Mitigation Project (NERMP): Lowering the degree of vulnerability in high-risk areas. In areas with strong seismic activity, necessary risk reduction measures are put in place.

• National Building Code (NBC) for India’s Earthquake preparedness: The National Building Code of India 2005 replaces the earlier codes.

Meeting the problems presented by natural disasters and adopting current, applicable international best practices are the key characteristics.

• Building Materials & Technology Promotion Council (BMTPC): Carries out initiatives for life-line structure retrofitting to raise awareness among the public and various governmental organisations.

• Ministry of Panchayati Raj used Backward Regions Grant Fund (BRGF) for rural development in earthquake prone areas.

• National Retrofit Program for India’s Earthquake Preparedness 2014: The NDMA released guidelines on “seismic retrofitting” along with specialists from several IITs and the necessary ministries.

• The RBI Guidelines refuse loans to any construction that does not adhere to the regulations for earthquake- resistant structures.

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The government launched two Mobile apps for India’s Earthquake preparedness

• ‘India Quake’– The mobile app, which was created by the National Center for Seismology, disseminates information about earthquakes in real-time.

• ‘Sagar Vani’-The smartphone app, designed to assist coastal communities, promptly notifies the user community of ocean-related information and alerts (such as high waves and Tsunami early warnings) for their protection.

• SACHET initiative of NDMA under Common Alerting Protocol (CAP) Project with C-DoT.

Tsunami

Tsunami

• Tsunamis (Japanese for ‘harbor wave’), also known as a seismic sea wave, are a series of very large waves with extremely long wavelengths, in the deep ocean, the length from crest to crest may be 100 km and more.

• It is usually generated by sudden displacements in the sea floor caused by earthquake, landslides, or volcanic activity.

• Most tsunamis, including the most destructive ones, are generated by large and shallow earthquakes which usually occur near geological plate boundaries, or fault- lines, where geological plates collide.

• When the seafloor abruptly deforms the sudden vertical displacements over large areas disturb the ocean’s surface, displace water, and generate tsunami waves.

• Since the wave height in the deep ocean will be only a few decimetres or less (i.e., a few inches), tsunamis are not usually felt aboard ships. Nor are they visible from the air in the open ocean. The waves could travel away from the triggering source with speeds exceeding 800 km/h over very long distances.

• They could be extremely dangerous and damaging when they reach the coast, because when the tsunami enters shallow water in coastal areas, the wave velocity will decrease accompanied by an increase in wave height.

• In shallow waters, tsunami wave heights can increase rapidly by several meters, sometimes exceeding 30 meters, leading to massive destruction within a short span.

• Example: The earthquake in the Indian Ocean on December 24, 2004, triggered a devastating tsunami that severely impacted India, particularly the southern coastline and the Andaman and Nicobar Islands.

• MeteoTsunamis: These are usually less destructive caused by weather systems, much smaller and focused along smaller regions of the oceans or even Great Lakes. These are often caused by fast moving storm systems reaching over 6 feet (2 meters) high, mostly seen at the east coast of the U.S.

    Map: Tsunami affected area in 2004    

Not following the coastal zone development regulations within 500 metres of the coast is a challenge. Development projects (residential, commercial, recreational, etc.) are still carried out making the local population more vulnerable.

• Mining of sand and other minerals from the sea makes the concerned area highly vulnerable to tsunamis.

• There is an urgent need to check unwanted construction and mining in ecologically sensitive coastal areas.

• Destruction of various coastal natural vegetation like Mangroves etc. has enormously exposed human habitations to the problems of storm surges and tsunami waves.

• Excessively wide area of Tsunami Risk makes it difficult to cover remote coastal areas, and need higher funding for disaster resilient preparation.

Tsunami Risk Mitigation

Tsunami Risk Mitigation Understanding Disaster Risk

• Research and Development Efforts

• Zoning/ Mapping

• Assess the status of existing important installations in coastal areas to withstand tsunami.

• Ensure fail-safe functioning of critical instruments

• Develop Sea Walls, Breakwaters, Tsunami river gates, forest barriers, mangroves and coral reefs.

• Dissemination of warnings, data, and information.

• Hazard Risk Vulnerability Assessment

• Promote studies, provide guidelines

• Studies on vulnerability covering social, economic, ecological, gender, and equity aspects

• Change in vulnerability and risk due under climate change scenarios

• Integrated Coastal Zone Management Plan (ICZMP):

• It is a process for the management of the coast using an integrated approach, regarding all aspects of the coastal zone, including geographical and political boundaries, in an attempt to achieve sustainability.

• The ICZM process recognizes coastal shorelands, lowlands, intertidal areas, lagoons, and open waters as a single interacting and indivisible resource unit that lies between the upland and the open sea

and whose future must be planned and managed in

combination.

• In this context, Union Ministry of Environment, Forests and Climate Change and The World Bank has come forward with an integrated approach to coordinate activities of various government agencies & departments for the sustainable management and usages of coastal resources maintaining the

natural environment. The Integrated Coastal Zone Management Project on pilot basis will be implemented in three states – Gujarat, Odisha and West Bengal.

Objectives of ICZMP include

• A. Formulation of Integrated Coastal Zone Management Plan for States

• B. Coastal Erosion and Associated Oceanographic Processes

• C. Vulnerability to Disaster

• D. Biodiversity Conservation

• E. Livelihood Security

• F. Pollution/ Environmental Quality Management

• G. Improvement and Conservation of Cultural/ Archaeological Assets

    Figure: Integrated Coastal Zone Management Programme for Tsunami affected Regions    

Inter-Agency Coordination

Inter-agency coordination is a key component of strengthening disaster risk governance. It is required among both central and state agencies in the field of Overall disaster governance, Response, Warnings, Information and data sharing and Non- structural measures.

Investing in DRR–Structural Measures

• Enhance the resilience of essential infrastructure and high-priority buildings.

• Develop shelters to protect against storm surges and tsunamis.

• Construct large-scale submerged sand barriers to mitigate tsunami impact.

• Conduct regular dredging of inlets and connected water bodies to help absorb the influx of water during a tsunami.

• Build submerged dykes, either in single or multiple rows along the coastline, to reduce the force of incoming tsunamis, along with inland dykes to safeguard critical installations.

• Ensure hazard-resistant construction, reinforcement, and retrofitting of all essential infrastructure and lifeline structures.

Investing in DRR–Non-Structural Measures

• Integrate disaster management (DM) considerations into both plan schemes and non-plan proposals across various ministries in accordance with established norms.

• Enforce and regulate relevant laws, including:

• Environmentally sustainable land-use zoning.

• Regulation of aquaculture and groundwater extraction.

• Ensure the implementation of prescribed standards across all departments and institutions.

• Formulate appropriate bylaws for rural areas, covering both engineered and non-engineered structures, while considering local conditions.

• Develop coastal sand dunes reinforced with seaweed, shrubs, or casuarina trees to enhance stabilization.

• Elevate ground levels above the design water level using natural beach sand to mitigate flooding risks.

• Establish coastal forests (green belts) by planting casuarina or coconut trees along the shoreline, ensuring a minimum coverage of 500 meters of beach width.

• Create bio-shields, such as mangrove plantations, to serve as natural barriers for communities living near estuaries.

• Safety Audits and evaluation of all lifeline structures and important facilities

• Promote private participation in disaster management facilities

Capacity Development

• Training and Capacity Building: Enhance the skills and knowledge of professionals in disaster management (DM).

• Educational Integration: Incorporate DM topics into academic curricula and develop technical expertise in various disaster-related subjects, including tsunamis.

• Awareness and Risk Reduction:

• Conduct mass media campaigns to promote disaster risk prevention, mitigation, and improved risk management.

• Encourage behavioral and attitudinal shifts through awareness programs and Information, Education, and Communication (IEC) initiatives.

• Advocate for the use of insurance and risk transfer mechanisms.

• Support the establishment and utilization of community radio for disaster awareness.

• Strengthen civil society networks for spreading awareness about Disaster Risk Reduction (DRR) and DM.

• Educate communities on the care and protection of animals affected by disasters.

• Emergency Preparedness:

• Organize mock drills and exercises to improve disaster response readiness.

• Distribute hazard zonation maps to coastal communities to raise awareness about tsunami risks and vulnerabilities.

• Community-Based Disaster Management:

• Enhance community resilience to disasters through a multi-hazard approach.

• Provide training for panchayat members, Self- Help Groups (SHGs), National Cadet Corps (NCC), National Service Scheme (NSS) participants, youth organizations, local community groups, and volunteers to improve disaster preparedness and response.

Steps Taken to Mitigate Tsunami

• The Indian Tsunami Early Warning System [ITEWS] comprises of a real time network of seismic stations, tsunami buoys and tide gauges. It is located at the Union Ministry of Earth Science’s Indian National Centre for Ocean Information Services [INCOIS] in Hyderabad.

• The real time seismic monitoring network comprises of 17 broadband seismic field stations transmitting real time data through V-SAT communication to the central receiving stations located at INCOIS and the National Centre for Seismology at New Delhi simultaneously for processing and interpretation.

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The ITEWS has a network of seven Tsunami Buoy Systems equipped with the bottom pressure recorders that transmit real time data through satellite communication to INCOIS 24X7. The buoys are strategically placed at locations where a tsunami wave can reach in less than 30 minutes in case an earthquake occurs anywhere in Andaman-Sumatra and Makran Subduction zones.

• In addition, INCOIS has established a real time network of 31 tide gauge stations.

• The Tsunami Warning Centre disseminates the advisories to the various stakeholders through multiple modes simultaneously such as email, fax, phone, GTS and SMS. The earthquake information, tsunami bulletins as well as the real-time sea-level observations are also made available on INCOIS website for officials, public and media.

• ITEWC is currently establishing a network of 35 strong motion accelerometers and GNSS receivers at Andaman & Nicobar Islands. The major objective of the exercise is to improve the capability to characterise the rupture direction and area as to enable quicker estimation of the tsunamigenic potential of an earthquake.

• The new geospatial technologies such as 3D GIS has transformed the way in which coasts can be mapped and managed, which in turn can be used for improving the accuracies of coastal inundation modelling.

• INCOIS has, among other things, initiated preliminary work on cutting edge research areas such as:

• (i) Multi-hazard Vulnerability Mapping,

• (ii) Real-time tsunami inundation modelling

• (iii) 3-D GIS.

• The broad scientific methodologies have been established and pilot work has been successfully completed for a few areas.

Floods

Flood Risk Mitigation

Understanding Disaster Risk

Modernization    ofObservation    Network    ; Assessment, Monitoring and Scientific studies.

Preparation of large-scale hazard maps of flood prone areas of high vulnerability.

Studies and monitoring of rivers flowing from neighbouring countries

Research and Development:

River Basin Analysis: Conduct comprehensive studies on river basins to understand their hydrological and ecological dynamics.

Research on Flood-Related Issues: Investigate challenges such as soil erosion due to river flooding, sediment transportation, river course alterations,

and the effective utilization of embankments.

Encouraging Research Initiatives: Support both internal and external research by offering grants to institutions and researchers for in-depth studies on flood management.

Hydrological and Morphological Assessments: Conduct thorough evaluations before implementing any major flood prevention or control measures.

Hazard Risk Vulnerability Assessment

Flood Hazard Zonation is also an essential step for future flood disaster management. The probability that a flood of a certain intensity will occur over an extended period is determined. Flood hazard is mainly used to define flood-prone zones.

National Remote Sensing Centre (NRSC)/ISRO has taken up development of Flood Hazard Zonation Maps using satellite data towards Disaster Risk Reduction, in addition to flood response.

The flood hazard maps prepared from satellite data were peer reviewed by a Committee constituted by National Disaster Management Authority (NDMA), which includes CWC (Central Water Commission), IMD (India Meteorological Department) and SDMA (State Disaster Management Authority).

Monitoring, Forecasting and Warning Systems

Dissemination of warnings, data, and information

    Figure: Integrated Flood Management    

Integrated flood management (IFM):

It calls for a paradigm shift from the traditional, fragmented and localized approach, and encourages the use of the resources of a river basin as a whole, employing strategies to maintain or augment the productivity of floodplains, while at the same time providing protective measures against losses due to flooding.

Since IFM is essentially a dynamic notion, including emerging issues, such as risk management, urban floods, climate variability and change, and adaptive management.

IFM is holistic approach derived from Integrated Water Resources Management (IWRM) principles that stresses the interrelationship between socio-economic development, environmental sustainability and flood-risk management.

Inter-Agency Coordination: Inter-agency coordination is a key component of strengthening disaster risk governance. It is required among both central and state agencies in the field of Overall disaster governance, Response, Warnings, Information and data sharing and Non-structural measures.

Investing in DRR–Structural Measures

Identification of Safe Shelters: Locate secure buildings and sites to serve as temporary refuges for both people and livestock evacuated from flood-prone areas.

Construction of Multi-Purpose Cyclone Shelters: Build shelters in coastal villages and habitations that are frequently affected by cyclones to provide safety during disasters.

Maintenance of Drainage Systems and Embankments: Ensure proper upkeep of drainage networks and flood embankments to mitigate waterlogging and flood risks.

Incorporation of Flood-Resistant Features: Integrate flood-resistant designs in the planning and execution of social housing projects in flood-prone regions.

Implementation of Flood Safety Measures: Enhance safety and minimize flood risks through strategies like catchment flood modeling.

Pre- and Post-Monsoon Inspections: Conduct regular assessments of dams and reservoirs to identify vulnerabilities and implement necessary reinforcements.

Monitoring Safety Enhancements: Ensure that all safety improvement measures are effectively executed as per prescribed standards.

Desilting and Dredging of Rivers: Improve water flow by removing excess silt, enhancing drainage, and diverting floodwaters through existing or newly constructed river channels.

Hazard-Resistant Construction and Infrastructure Strengthening: Strengthen and retrofit lifeline structures and critical infrastructure to enhance resilience against floods and related disasters.

Investing in DRR–Non-Structural Measures

Implement regulations for land use in low-lying areas in accordance with flood control guidelines.

• Regulate habitation in low-lying zones along rivers, streams, and drainage systems to reduce flood risks.

• Ensure the effective implementation of a comprehensive plan to manage and mitigate floods.

• Periodically assess and revise operational guidelines for all major dams and reservoirs to enhance flood preparedness.

• Prevent and remove encroachments that obstruct natural water channels and drainage systems.

• Update and enforce relevant policies and regulations in flood-prone areas to minimize risks.

• Restrict activities that involve reclaiming wetlands and natural low-lying areas to maintain their role in flood control.

• Develop and implement strategies to protect wetlands and natural drainage systems to aid in flood moderation.

• Implement watershed management practices, including catchment area treatment and afforestation, to reduce flood risks.

• Promote involvement of private entities in disaster management infrastructure and facilities.

Capacity Development

• Training Programs for Government Staff and Professionals: Conduct orientation sessions on veterinary care and support for animals affected by disasters.

• Integration of Disaster Response in Youth Training: Include search and rescue operations in training programs for village volunteers and youth, with a focus on protecting disaster-affected animals.

• Curriculum Revision for Engineering Courses: Update undergraduate engineering syllabi to cover flood hazard mitigation and disaster-resistant construction techniques.

• Encouragement of Emergency Drills: Facilitate planning and execution of emergency drills across all ministries and States/UTs.

• Skill Development for Disaster-Resistant Construction: Provide training in building multi-hazard-resistant infrastructure, particularly in flood-prone areas.

• Public Awareness Campaigns: Utilize mass media, community radio, and other platforms to enhance disaster preparedness awareness.

• Gender-Sensitive and Inclusive Capacity Building: Ensure disaster management strategies incorporate gender equity and social inclusion at all levels.

• Community Disaster Preparedness: Strengthen local communities’ ability to manage and respond to disasters through a multi-hazard approach.

• Training for Local Organizations and Volunteers: Conduct training for panchayat members, SHGs, NCC, NSS, youth, and other community organizations to enhance disaster response skills.

Steps Taken to Mitigate Floods

Establishment of Rashtriya Barh Ayog (RBA): The National Flood Commission was formed by the Ministry of Agriculture and Irrigation in 1976 to assess India’s flood control measures after the National Flood Control Program of 1954 yielded limited success.

Financial Assistance for Flood Management: The Central Government has been funding flood control efforts under the Flood Management Programme (FMP) since the XI Plan.

Following initiatives have yielded significant results :

• National Flood Management Framework: A structured approach to flood mitigation and preparedness.

• Hydro-Meteorological Data Policy: Ensuring efficient dissemination of flood-related data for better decision- making.

• Deployment of Mobile Pump Units: Used during Delhi floods to manage waterlogging and mitigate flood impact.

• ‘Flood Watch’ Mobile Application: Provides real-time flood-related updates to enhance preparedness and response.

During X Plan, following four schemes were sanctioned to provide central assistance to the flood prone states to take up flood control and river management works in critical areas:

• Critical Anti-erosion works in Ganga Basin States (a Centrally Sponsored Scheme)

• Critical Flood Control and Anti Erosion Schemes in Brahmaputra and Barak Valley States (a State Sector Scheme),

• Improvement of Drainage in critical areas in the country (a State Sector Scheme)

• Critical Anti-erosion Works in Coastal and other than Ganga Basin States (a State Sector Scheme).

River Management Activities and Works Related to Border Areas (RMBA)

• During XI Plan, Government of India had approved implementation of the Central Sector Scheme “River Management Activities and Works related to Border Areas” for taking up non-structural measures such as Hydrological Observation and Flood Forecasting works on common border rivers, payment to neighbouring countries (China) for supplying HO data on common rivers, investigation of WR projects in neighbouring countries, activities of GFCC and Pancheswar Development Authority (PDA) was funded through this scheme.

• In addition to above activities, 100% Central Assistance was also provided for taking up structural measures such

as Anti Erosion/Flood Management schemes on rivers on international borders and Union Territories.

National Commission for Water Resources (1999):

• It suggested that storage dams and embankments provide effective protection to flood-prone areas and an urgent need to enact the flood plain zoning Act.

National Water Policy (2012):

• Formulated by the Ministry of Jal Shakti with the objective to take cognizance of the existing flood situation and to propose a plan of action from the national perspective. It suggested that through reservoir operation, the flood cushion can be set up to reduce the trapping of sediment during the flood season.

National Hydrology Project (2016):

• It is a central sector scheme under the Ministry of Water Resources, River Development & Ganga Rejuvenation; with 50% of the outlay amount received from the World Bank loan. The project gathers hydro-meteorological data which will be stored and analyzed on a real-time basis and can be accessed by any user at the State, District, and Village level.

Flood Plain Zoning

• Flood-plain zoning is a concept central to flood plain management. This concept recognises the basic fact that the flood plain of a river is essentially its domain and any intrusion into or developmental activity therein must recognise the river’s ‘right of way’.

• Flood-plain zoning measures aim at demarcating zones or areas likely to be affected by floods of different magnitudes or frequencies and probability levels, and specify the types of permissible developments in these zones, so that whenever floods actually occur, the damage can be minimised, if not avoided.

• The Central Water Commission (CWC) has been continuously impressing upon the states the need to take follow-up action to implement the flood plain zoning approach.

• A model draft bill for Flood Plain Zoning Legislation was also circulated by the union government in 1975 to all the states.

• There has been passive resistance on the part of the states to follow up the various aspects of flood plain management including possible legislation.

Flood Proofing

• Flood proofing measures adopted in India in the past, consisted in raising a few villages above pre-determined flood levels and connecting them to nearby roads or high lands.

• Under this programme, several thousand villages were raised in Uttar Pradesh in the fifties. In West Bengal

and Assam also land-fills were attempted in villages to keep houses above flood levels even though nearby agricultural lands were liable to inundation.

• During X Plan, the Government of Bihar had also constructed, with Central assistance, the raised platforms for safety of the people in flood prone areas of North Bihar.

CWC National Flood Forecasting Network

• Flood Forecasting and flood warning in India was commenced in a small way in the year 1958 with the establishment of a unit in the Central Water Commission (CWC), New Delhi, for flood forecasting for the river Yamuna at Delhi.

• Presently, there are 878 Hydrological and Hydro- meteorological sites being operated by CWC across the country covering 20 river basins for gauge, discharge, sediment & water quality observations.

• The formulation of a forecast requires effective means of real time data communication network from the forecasting stations and the base stations (380 nos approx at present).

• Flood Foreasting system comprises of Level Forecasting and Inflow Forecasting.

• The Level Forecasts help the user agencies to decide mitigating measures like evacuation of people and shifting people and their movable property to safer locations.

• The Inflow Forecasting is used by various dam authorities in optimum operation of reservoirs for safe passage of flood downstream as well as to ensure adequate storage in the reservoirs for meeting demand during non-monsoon period.

Watershed Management

• The watershed management measures include developing and conserving the vegetative and soil covers and also to undertake structural works like check- dams, detention basins, diversion channels, etc.

• In the watershed management of upper catchment, land treatment through afforestation and grass land development practices should be supplemented by structural works for retarding the water velocity and arresting silt.

Community based Management

The Intergovernmental Oceanographic Commission (IOC) of UNESCO has started a community performance- based programme known as “Tsunami Ready” for the promotion of tsunami preparedness by actively involving the public, community leaders, and national and local emergency management agencies.

Flood Risk Mitigation

Flood Risk Mitigation

Understanding Disaster Risk

Modernization    ofObservation    Network    ; Assessment, Monitoring and Scientific studies.

Preparation of large-scale hazard maps of flood prone areas of high vulnerability.

Studies and monitoring of rivers flowing from neighbouring countries

Research and Development:

River Basin Analysis: Conduct comprehensive studies on river basins to understand their hydrological and ecological dynamics.

Research on Flood-Related Issues: Investigate challenges such as soil erosion due to river flooding, sediment transportation, river course alterations,

and the effective utilization of embankments.

Encouraging Research Initiatives: Support both internal and external research by offering grants to institutions and researchers for in-depth studies on flood management.

Hydrological and Morphological Assessments: Conduct thorough evaluations before implementing any major flood prevention or control measures.

Hazard Risk Vulnerability Assessment

Flood Hazard Zonation is also an essential step for future flood disaster management. The probability that a flood of a certain intensity will occur over an extended period is determined. Flood hazard is mainly used to define flood-prone zones.

National Remote Sensing Centre (NRSC)/ISRO has taken up development of Flood Hazard Zonation Maps using satellite data towards Disaster Risk Reduction, in addition to flood response.

The flood hazard maps prepared from satellite data were peer reviewed by a Committee constituted by National Disaster Management Authority (NDMA), which includes CWC (Central Water Commission), IMD (India Meteorological Department) and SDMA (State Disaster Management Authority).

Monitoring, Forecasting and Warning Systems

Dissemination of warnings, data, and information

    Figure: Integrated Flood Management    

Integrated flood management (IFM):

It calls for a paradigm shift from the traditional, fragmented and localized approach, and encourages the use of the resources of a river basin as a whole, employing strategies to maintain or augment the productivity of floodplains, while at the same time providing protective measures against losses due to flooding.

Since IFM is essentially a dynamic notion, including emerging issues, such as risk management, urban floods, climate variability and change, and adaptive management.

IFM is holistic approach derived from Integrated Water Resources Management (IWRM) principles that stresses the interrelationship between socio-economic development, environmental sustainability and flood-risk management.

Inter-Agency Coordination: Inter-agency coordination is a key component of strengthening disaster risk governance. It is required among both central and state agencies in the field of Overall disaster governance, Response, Warnings, Information and data sharing and Non-structural measures.

Investing in DRR–Structural Measures

Identification of Safe Shelters: Locate secure buildings and sites to serve as temporary refuges for both people and livestock evacuated from flood-prone areas.

Construction of Multi-Purpose Cyclone Shelters: Build shelters in coastal villages and habitations that are frequently affected by cyclones to provide safety during disasters.

Maintenance of Drainage Systems and Embankments: Ensure proper upkeep of drainage networks and flood embankments to mitigate waterlogging and flood risks.

Incorporation of Flood-Resistant Features: Integrate flood-resistant designs in the planning and execution of social housing projects in flood-prone regions.

Implementation of Flood Safety Measures: Enhance safety and minimize flood risks through strategies like catchment flood modeling.

Pre- and Post-Monsoon Inspections: Conduct regular assessments of dams and reservoirs to identify vulnerabilities and implement necessary reinforcements.

Monitoring Safety Enhancements: Ensure that all safety improvement measures are effectively executed as per prescribed standards.

Desilting and Dredging of Rivers: Improve water flow by removing excess silt, enhancing drainage, and diverting floodwaters through existing or newly constructed river channels.

Hazard-Resistant Construction and Infrastructure Strengthening: Strengthen and retrofit lifeline structures and critical infrastructure to enhance resilience against floods and related disasters.

Investing in DRR–Non-Structural Measures

Implement regulations for land use in low-lying areas in accordance with flood control guidelines.

• Regulate habitation in low-lying zones along rivers, streams, and drainage systems to reduce flood risks.

• Ensure the effective implementation of a comprehensive plan to manage and mitigate floods.

• Periodically assess and revise operational guidelines for all major dams and reservoirs to enhance flood preparedness.

• Prevent and remove encroachments that obstruct natural water channels and drainage systems.

• Update and enforce relevant policies and regulations in flood-prone areas to minimize risks.

• Restrict activities that involve reclaiming wetlands and natural low-lying areas to maintain their role in flood control.

• Develop and implement strategies to protect wetlands and natural drainage systems to aid in flood moderation.

• Implement watershed management practices, including catchment area treatment and afforestation, to reduce flood risks.

• Promote involvement of private entities in disaster management infrastructure and facilities.

Capacity Development

• Training Programs for Government Staff and Professionals: Conduct orientation sessions on veterinary care and support for animals affected by disasters.

• Integration of Disaster Response in Youth Training: Include search and rescue operations in training programs for village volunteers and youth, with a focus on protecting disaster-affected animals.

• Curriculum Revision for Engineering Courses: Update undergraduate engineering syllabi to cover flood hazard mitigation and disaster-resistant construction techniques.

• Encouragement of Emergency Drills: Facilitate planning and execution of emergency drills across all ministries and States/UTs.

• Skill Development for Disaster-Resistant Construction: Provide training in building multi-hazard-resistant infrastructure, particularly in flood-prone areas.

• Public Awareness Campaigns: Utilize mass media, community radio, and other platforms to enhance disaster preparedness awareness.

• Gender-Sensitive and Inclusive Capacity Building: Ensure disaster management strategies incorporate gender equity and social inclusion at all levels.

• Community Disaster Preparedness: Strengthen local communities’ ability to manage and respond to disasters through a multi-hazard approach.

• Training for Local Organizations and Volunteers: Conduct training for panchayat members, SHGs, NCC, NSS, youth, and other community organizations to enhance disaster response skills.

Steps Taken to Mitigate Floods

Establishment of Rashtriya Barh Ayog (RBA): The National Flood Commission was formed by the Ministry of Agriculture and Irrigation in 1976 to assess India’s flood control measures after the National Flood Control Program of 1954 yielded limited success.

Financial Assistance for Flood Management: The Central Government has been funding flood control efforts under the Flood Management Programme (FMP) since the XI Plan.

Following initiatives have yielded significant results :

• National Flood Management Framework: A structured approach to flood mitigation and preparedness.

• Hydro-Meteorological Data Policy: Ensuring efficient dissemination of flood-related data for better decision- making.

• Deployment of Mobile Pump Units: Used during Delhi floods to manage waterlogging and mitigate flood impact.

• ‘Flood Watch’ Mobile Application: Provides real-time flood-related updates to enhance preparedness and response.

During X Plan, following four schemes were sanctioned to provide central assistance to the flood prone states to take up flood control and river management works in critical areas:

• Critical Anti-erosion works in Ganga Basin States (a Centrally Sponsored Scheme)

• Critical Flood Control and Anti Erosion Schemes in Brahmaputra and Barak Valley States (a State Sector Scheme),

• Improvement of Drainage in critical areas in the country (a State Sector Scheme)

• Critical Anti-erosion Works in Coastal and other than Ganga Basin States (a State Sector Scheme).

River Management Activities and Works Related to Border Areas (RMBA)

• During XI Plan, Government of India had approved implementation of the Central Sector Scheme “River Management Activities and Works related to Border Areas” for taking up non-structural measures such as Hydrological Observation and Flood Forecasting works on common border rivers, payment to neighbouring countries (China) for supplying HO data on common rivers, investigation of WR projects in neighbouring countries, activities of GFCC and Pancheswar Development Authority (PDA) was funded through this scheme.

• In addition to above activities, 100% Central Assistance was also provided for taking up structural measures such

as Anti Erosion/Flood Management schemes on rivers on international borders and Union Territories.

National Commission for Water Resources (1999):

• It suggested that storage dams and embankments provide effective protection to flood-prone areas and an urgent need to enact the flood plain zoning Act.

National Water Policy (2012):

• Formulated by the Ministry of Jal Shakti with the objective to take cognizance of the existing flood situation and to propose a plan of action from the national perspective. It suggested that through reservoir operation, the flood cushion can be set up to reduce the trapping of sediment during the flood season.

National Hydrology Project (2016):

• It is a central sector scheme under the Ministry of Water Resources, River Development & Ganga Rejuvenation; with 50% of the outlay amount received from the World Bank loan. The project gathers hydro-meteorological data which will be stored and analyzed on a real-time basis and can be accessed by any user at the State, District, and Village level.

Flood Plain Zoning

• Flood-plain zoning is a concept central to flood plain management. This concept recognises the basic fact that the flood plain of a river is essentially its domain and any intrusion into or developmental activity therein must recognise the river’s ‘right of way’.

• Flood-plain zoning measures aim at demarcating zones or areas likely to be affected by floods of different magnitudes or frequencies and probability levels, and specify the types of permissible developments in these zones, so that whenever floods actually occur, the damage can be minimised, if not avoided.

• The Central Water Commission (CWC) has been continuously impressing upon the states the need to take follow-up action to implement the flood plain zoning approach.

• A model draft bill for Flood Plain Zoning Legislation was also circulated by the union government in 1975 to all the states.

• There has been passive resistance on the part of the states to follow up the various aspects of flood plain management including possible legislation.

Flood Proofing

• Flood proofing measures adopted in India in the past, consisted in raising a few villages above pre-determined flood levels and connecting them to nearby roads or high lands.

• Under this programme, several thousand villages were raised in Uttar Pradesh in the fifties. In West Bengal

and Assam also land-fills were attempted in villages to keep houses above flood levels even though nearby agricultural lands were liable to inundation.

• During X Plan, the Government of Bihar had also constructed, with Central assistance, the raised platforms for safety of the people in flood prone areas of North Bihar.

CWC National Flood Forecasting Network

• Flood Forecasting and flood warning in India was commenced in a small way in the year 1958 with the establishment of a unit in the Central Water Commission (CWC), New Delhi, for flood forecasting for the river Yamuna at Delhi.

• Presently, there are 878 Hydrological and Hydro- meteorological sites being operated by CWC across the country covering 20 river basins for gauge, discharge, sediment & water quality observations.

• The formulation of a forecast requires effective means of real time data communication network from the forecasting stations and the base stations (380 nos approx at present).

• Flood Foreasting system comprises of Level Forecasting and Inflow Forecasting.

• The Level Forecasts help the user agencies to decide mitigating measures like evacuation of people and shifting people and their movable property to safer locations.

• The Inflow Forecasting is used by various dam authorities in optimum operation of reservoirs for safe passage of flood downstream as well as to ensure adequate storage in the reservoirs for meeting demand during non-monsoon period.

Watershed Management

• The watershed management measures include developing and conserving the vegetative and soil covers and also to undertake structural works like check- dams, detention basins, diversion channels, etc.

• In the watershed management of upper catchment, land treatment through afforestation and grass land development practices should be supplemented by structural works for retarding the water velocity and arresting silt.

Community based Management

The Intergovernmental Oceanographic Commission (IOC) of UNESCO has started a community performance- based programme known as “Tsunami Ready” for the promotion of tsunami preparedness by actively involving the public, community leaders, and national and local emergency management agencies.

El-nino and La Nina

El-Nino and La Nina

El Nino:

During a typical year with normal weather patterns, winds move westward, pushing warm surface water toward the western Pacific Ocean, which facilitates the upwelling of cold water from deeper ocean layers.

However, in certain years, when these winds weaken, warm water extends across most of the tropical Pacific Ocean. This prevents the rise of cool, nutrient- rich water along the eastern Pacific coast.

As a result, fish populations decline, and significant climate changes occur. The warm water shifts rainfall eastward, leading to droughts in Southern Asia and Australia while causing floods in North and South America.

La Nina:

La Nina is the reverse of El Nino. At the end of December, westbound winds get stronger than usual, pushing warm water further west than normal. As a result, there is enhanced upwelling of cold sea water.

This action allows hurricanes crossing the Atlantic to move farther west and to become more powerful than usual.

During a La Niña year, winter temperatures are warmer than normal in the South and cooler than normal in the North.

La Niña can also lead to a more severe hurricane season. La Niña causes the jet stream to move northward and to weaken over the eastern Pacific.

However, La Nina is generally good for the Indian summer monsoon.

The La Niña phase of the equatorial Pacific Ocean, active since 2021, had been expected to extend into 2023, marking only the third rare “triple-dip” event since 1950. Such long-lasting episodes usually aggravate climate extremes, intensifying floods in some areas and droughts in others. By 2024, however, La Niña weakened, and a short, weak resurgence occurred in late 2024 before fading by March 2025. The Pacific has now shifted to ENSO-neutral conditions, though forecasts suggest a possible return of a weak La Niña by late 2025, which could again influence global rainfall and temperature patterns.

El Niño and La Niña events happen every two to seven years. They usually last for 9-12 months but have been known to last for several years at a time.

• The World Metrological Organisation (WMO) predicts that global temperatures are likely to surge to record levels in the next five years due to a combination of climate change and El Niño. In 2016, it contributed to drought and food insecurity that affected tens of millions of people across southern and eastern Africa.

Impact of El Nino and La Nina

• However, El Niño and La Niña events are not mirror images of each other. They differ in length and strength.

• El Niño episodes occur more frequently and are usually associated with more impactful weather events. An El Niño is more likely to be a single-year event.

• La Niña, on the other hand, has a longer run. That is why multi-year La Niña events, those that continue for more than 12 months, are quite common.

Impact of El-Nino

• They can also cause increased rainfall in southern South America, the southern United States, the Horn of Africa and central Asia.

• During summer in the northern hemisphere, El Niño’s warm waters can result in more intense tropical cyclones in the western Pacific, but fewer Atlantic hurricanes.

• In Ecuador and Peru, where flooding earlier this year has already fueled a rising dengue outbreak, the risk is now compounded by expectations of El Niño–driven rains in early 2025. By contrast, in southern Africa, although vast drought-affected areas have struggled with cholera outbreaks (with over 178,000 confirmed cases in Eastern and Southern Africa between 2024 and early 2025) , it remains unclear whether drier conditions will ease transmission or worsen water scarcity and sanitation challenges, thus influencing the epidemic’s trajectory.

• With all the extra heat at the surface of the Pacific Ocean, energy is released into the atmosphere, causing an overall warming of the global climate temporarily. Years in which

El Niño occurs tend to feature higher temperatures across the globe.

    Figure: Impact of El Nino on Fishes    

• In Asian countries, there is typically a decrease in rice production. With an increase in droughts on the western side of the equatorial Pacific, GDP in the countries in that area tend to drop during the El Niño cycle.

• In non-Asian countries such as Australia, the droughts can cause a decrease in the harvesting of other crops, like wheat.

• Meanwhile, the dramatic increase in rainfall on the eastern equatorial Pacific cause flooding, property damage, displacement and seek shelter elsewhere.

• Fishing in equatorial coastal countries like Ecuador and Peru becomes difficult, as fish in the waters near these countries tend to disappear in the months of December and January.

• Overall, the drastic change in weather that occurs due to El Niño has a negative economic impact on many countries near the equator. While normal years offer more stable weather, thus leading to more predictable effects on certain markets, El Niño years have a dramatic shift in the weather pattern that leads to extreme weather on either side of the equatorial Pacific. This extreme weather, whether it be drought or flood, has a negative impact on the living conditions and extraction of natural resources in Tropical countries.

Impact of La Nina

• In most parts of the United States, for example, La Niña is associated with very dry winters.

• In Australia and Indonesia, and generally in the tropical region, La Niña is expected to bring more rainfall.

• The widespread drought in the United States and flooding in eastern Australia this year could have been a result of the prolonged La Niña.

• The excessive rainfall in Pakistan, which is experiencing its worst flooding disaster, can also be blamed in part on La Niña.

• It said that the persistence of La Niña was most likely to result in a worsening of the drought in Africa.

Cloudbursts and Flash Floods

Cloudbursts and Flash Floods

Cloudburst is defined as an extreme amount of precipitation in a short span of time, which creates flash- flood conditions. It is often accompanied by thunder and lightning.

A cloudburst can occur anytime and at any place which is affected by convective weather systems.

According to Indian Meteorological Department (IMD), Cloudburst is an unexpected precipitation that exceeds 100mm (or 10 cm) per hour across a region of land that is between 20 and 30 square kilometres.

Most cloudbursts take place between 1,000 and 2,500 metres above sea level, and they are followed by significant flooding particularly Flash Floods and Landslides.

• Intense weather events, especially when more than 10 centimeters (3.94 inches) of rainfall occurs within a 10 square kilometers (3.86 square miles) region within an hour, are called Cloudbursts.

• Flash Floods occur in a much shorter span of time (say, when rainfall creates flooding in less than 6 hours) and are highly localised. Flash-floods are mostly the result of cloudbursts or blockage of river channel due to landslides.

    Figure: Cloud Burst    

• As India surrounded by oceans from three sides. Hence, it is a favourable location for convective weather systems.

•
During Cloudburst, massive coagulated clouds with heavy water content hover, over a very small location. They simply collapse under their own weight causing flash floods.

    Figure: Mechanism of Cloudburst    

• Famous Example is 2013 Uttarakhand Cloudburst and Flash Floods where heavy snowfall occurred in

Himalayas and non-stop heavy rainfall. It helped the snow to melt fast from Chorabari Glacier as water has a higher heat capacity and molecules in liquid water are more tightly packed than air, leading to greater rate of heat transfer and snow melting from Chorabari glacier. This led to rise in water level in the river Mandakini and Chorabari Lake.

• These flash floods washed the mud, stones and slush (partially melted snow) from mountains into rivers. Thus, all those shops, hotels, apartments were destroyed and road network erased hence relief could not reach on time.

• Flash floods caused by cloudbursts have caused significant damage to villages and cities in the Himalayan regions of Kashmir and Ladakh in India. Examples of Mumbai cloudburst of July 2005, Kedarnath cloudburst of 2013 which caused more than 5,000 deaths and loss of property worth crores of rupees, Cloud Burst in Dehradun 2022, Amarnath cave, 2022, Sikkim 2023.

• In Uttarkashi (Uttarakhand), August 5, 2025: A cloudburst in the Dharali area near Harsil triggered flash floods and mudslides. Several houses, hotels, and roads were destroyed; at least 4-5 people died and dozens went missing.

• In Chositi, Kishtwar district (Jammu & Kashmir), August 14, 2025: A cloudburst led to flash floods that killed about 68 people, injured over 300, and left many missing. The affected included pilgrims on the Machail Mata Yatra route.

• In Uttarakhand (Rudraprayag and Chamoli districts), August 29, 2025: Cloudbursts caused flash floods, with at least 4 people reported dead and several missing. Families were trapped under debris in affected areas.

Do cloudbursts happen only in the mountains and hilly areas?

• There is a greater probability of them occurring in mountainous zones, though they occur in plains also.

• When vapour saturated clouds face upward movement of very warm current of air.

• New drops are formed and existing raindrops increase in size. After a point, the raindrops become too heavy for the cloud to hold on to, and they fall together in a quick flash.

• Thus, hilly areas help in heated air currents rising vertically upwards, thereby, increasing the probability of a cloudburst situation.

• Cloudbursts get acknowledged only when they result in largescale destruction of life and property, which happens mainly in mountainous regions.

Is 2013 Incident a man-made disaster?

• There are various causes of Uttarakhand incident which include

    Figure: Consequences of Cloudbursts    

• Roads causing landslides

• Huge expansion of roads and transport.

• Heavy machines plying the earth everyday.

• Even dynamites are used to cut the mountains and make roads.

• Unscientific construction: They say damage caused by cloudbursts is also increasing because of unplanned development in mountain regions.

• In 2012, government notification declared the region of Gaumukh and Uttarakashi, along the Bhagirathi River, as an Eco-Sensitive Zone which banned:

• Hydropower projects which changes river courses, poor structural safety

• Mining and use of dynamites

• Construction activities, especially hotels, resorts, guest houses and travel lodges on the river bed.

• Lack of Political Will

• Ad-hoc and unplanned development, without medium term or long-term plan or vision apart from corruption by builders, mining mafias and bureaucrats.

• Outdated Disaster Management Approach

• The emphasis has been on post-disaster response, rescue, evacuation and relief rather than following the ‘Disaster Management Continuum’ that lays more stress on pre-disaster early warning, mitigation and risk reduction of disaster events.

• Inefficient Bodies and Lack of Infrastructure

• Indian Metrological Department was unable to alert as it didn’t have Doppler radars in the Himalayan region to predict onset of cloudbursts.

• National Disaster Management Authority (NDMA)

didn’t even have sufficient life-jackets in Rudraprayag.

• Overall, there was no accountability and no coordination.

• Global Warming and Climate Change

• Experts attribute the increasing frequency of cloudbursts to global warming, which is resulting in more evaporation of water and because of this dense cumulonimbus clouds are forming, resulting in intense rainfall.

Can we Predict and Prevent Cloudbursts?

• The specific location and time of cloud burst can be predicted in NOWCAST mode only, i.e. a few hours in advance. To detect these sudden developments, you need a Doppler Weather Radar (DWR).

    Figure: Cloud burst Forecasting    

Doppler Weather Radar (DWR)

• By and large, Meteorologists use there are three different types of weather radars:

• Conventional: gives information only about the rainfall estimation

• Doppler: Measuring rainfall, winds and clouds, can cover an area ~400 km

• Polarisation radar (or multi-parameter radar): measure winds, rainfall (including shape and number of raindrops)

• Benefits of Doppler Weather Radar

• Radar uses the Doppler Effect in microwaves. When Microwaves are reflected from objects at different times, this Radar detects their relative position. Thus, Doppler Radar can detect even tiny water particles in clouds and in which direction they’re moving.

• Doppler radar has a detection range of ~400 kms. It can transmit information about a cloud, its distance from land, its composition, which direction it is moving and even minute details like the number and size of water droplets found in a cloud.

• We can predict the amount of rainfall to an area, 2-3 hours in advance. Thus, if a flood-like situation is likely to happen in Mumbai, BMC could be alerted to avert a 2005-like disaster.

• It can predict thunderstorms as well.

• However, Real-time Early Warning of Cloudbursts has still not been developed. Doppler radars that can predict sudden changes in the weather about three to six hours in advance can assist in early warning for cloudbursts.

•
These have been fixed in the western and eastern Himalayas and in the plains as well — numbering 33 at present — with their presence continuously increased to be used in a Multi-Hazard Early Warning System related to heavy rainfall and snow.

• These are being upgraded by the Union Ministry of Earth Sciences, with the number targeted to be raised to 90, to forecast cloudbursts and heavy rainfall events at least two days in advance, which would assist in evacuating people beforehand.

Glacial Lake Atlas

• National Remote Sensing Centre, as one of the Central Implementing Agency of National Hydrology Project (NHP) sponsored by Ministry of Jal Shakti, Department of Water Resources, River Development and Ganga Rejuvenation (DoWR, RD&GR), Govt. of India. As part of this, NRSC carried out inventory & mapping of Glacial Lakes of size ≥0.25ha Himalayan Region of Indian River Basins. Using the above, NRSC brought out Glacial Lakes Atlas of Indus and Ganga river basins.

• These atlases are useful for identifying the potential critical glacial lakes and consequent GLOF risk assessment. It also assists disaster mitigation planning and related programs for Central and State Disaster Management Authorities.

Crisis Mapping

• Crisis mapping is the real-time data gathering and analysis during natural disaster or riots, elections etc.

• During Uttarakhand tragedy,International Network of Crisis Mappers came to help. These crisis mappers

monitor different channels of information on Uttarakhand. Example

• Official sources,

• Blogs, social media, facebook twitter

• NGOs

• News Media

• Using such data, the Crisis Mappers generate ‘situation reports’. They also update with vital information an online crisis map set up by the Google having information on rescued people, cleared areas, people stranded, relief camps, medical centres, road networks and so on.

• Thus, crisis mapping helps bridge the gap between

• Information-seekers vs providers

• Government vs public

• Situation on the ground vs action that needs to be taken

• Ushahidi is an open-source platform for crisis mapping during 2010 Haiti Earthquake. They even had an international SMS number which was created for people to input information relating to the quake.

• South Asian Flash Flood Guidance System by IMD.

• Google Person Finder is a web application that -

• Allows individuals to post and search for the status of relatives or friends affected by a disaster.

• It also lets press agencies, non-governmental agencies etc. contribute to the database and receive updates. This was utilized during rescue & relief operations in Uttrakhand flash floods.

Mitigation of Cloudbursts and Flash Floods

Mitigation of Cloudbursts and Flash Floods

Measures of NDMA (National Disaster Management Authority) for cloudbursts:

• Follow Disaster Management Continuum Approach, which is safe, economically feasible and advantageous.

• Technology: Real-time Early Warning of Cloudbursts must be developed. Doppler Radar system and Early Warning Dissemination systems be expanded.

• Advanced Planning with Community-Based Disaster Management must be promoted.

• Localized planning that incorporates the surrounding community and considers the ecological fragility of the region.

• Promote planned developments in climate- vulnerable regions such as the Himalayas.

• When there are known flood paths, it is best to avoid any construction in those regions.

• It is important for people living on foothills or slopes to be moved to higher ground when heavy rains are likely to occur to minimize loss of life.

• Cloudburst Hotspots have to be identified, risk mapping done and management initiated from these places.

•
Infrastructural development like strengthening of dams, barrages, and embankments to regulate and control water flow.

• Adoption of eco-friendly legislation and eco-aware tourism for the development of the region.

• Ecological Stabilization:

• To reduce the chances of landslides, there afforestation should be promoted.

• Similarly, ensuring smooth flow and drainage of rainwater in the plains would prevent human, animal and infrastructural losses after cloudbursts and heavy rain.

Mitigation can be made more successful by utilising and leveraging local resources and expertise.

By joining and collaborating with local organisations like Gram Sabhas, and Panchayats, NGOs and communities will improve the disaster management system as a whole.

The capacity and capability building of such human resources be ensured.

• Watershed Management that stabilises the hill landscape and ensures better tackling of resultant landslides, flash floods, mudflows and land-caving needs to be adopted. These measures should be strategically implemented first in the hotspots.

• The computerisation of the distribution of monetary disaster relief has to be completed where not yet accomplished for ensuring instantaneous flow to the needy.

• Immediate relief in the form of food, water and medicines needs to be provided for preventing post- disaster complications. The rehabilitation operation should be executed with the purpose of bringing back sustainable livelihoods and assisting people in returning to normal life.

• Where the damage is colossal, reconstruction and rehabilitation must be undertaken on a war footing. All these activities have to be taken to the last mile and assessed through participatory monitoring to gauge the effectiveness of the interventions.

• The implementation of all these steps of the disaster management continuum, as contained in the National Policy of Disaster Management, 2009, would assist in achieving cloudburst resilience and reflect India’s commitment to comply with the UN’s Sendai Framework of Disaster Risk Reduction that various countries are trying to achieve before 2030.

Urban Floods

• Urban Floods

• The problem of urban flooding is a result of both natural factors and land-use changes brought about by urban development.

• Urban flooding differs significantly from rural flooding due to urbanization, which results in developed catchments that amplify flood peaks by 1.8 to 8 times and increase flood volumes by up to six time.

• It occurs due to a combination of meteorological, hydrological, and human-induced factors. Changes in land use contribute to rapid flooding in urban areas, leading to high water flow.

• Several major Indian cities have experienced loss of life and property, disruptions in transportation and power supply, and outbreaks of epidemics. Therefore, managing urban flooding should be treated as a top priority.

• The consequences of urban flooding can be extensive, including temporary displacement of people, damage to infrastructure, decline in water quality, and increased risk of disease outbreaks

• Urban Flood vs Rural Flood

• Widespread rural flooding is primarily caused by several key factors:

• During the monsoon season, rivers carry a heavy sediment load from their catchments. When combined with the inadequate capacity of rivers to hold water, this leads to flooding, drainage congestion, and erosion of riverbanks.

• Cyclones, cyclonic circulations, and cloudbursts can trigger flash floods, resulting in significant losses. Additionally, some rivers responsible for severe flooding in India originate from neighboring countries, adding another layer of complexity to the issue.

•
Urban flooding differs greatly from rural flooding due to urbanization, which results in developed catchments that increase flood peaks by 1.8 to 8 times and flood volumes by up to six times.

• Flooding occurs rapidly due to shorter flow times, sometimes within minutes.

• Developed catchments in cities lead to higher runoff levels.

• The predominance of solid surfaces prevents water infiltration and percolation, worsening the situation.

• High population density in urban areas increases the number of people at risk, leading to greater loss of life.

• Flooding also raises exposure to infections, further heightening human vulnerabilities.

• Poor urban planning and inefficient drainage systems exacerbate flooding issues.

• Since urban areas are economic hubs with critical infrastructure, flood-related damage can have far- reaching consequences beyond local areas, impacting the entire nation.

Urban Flood Risk in India

India has witnessed a rising trend of urban flooding disasters over the years, severely impacting major cities. Some of the most significant instances include Hyderabad in 2000, Ahmedabad in 2001, Chennai in 2004, Mumbai in 2005, and Delhi in 2023, among others.

    Figure: Causes of Urban Floods    

• A distinct characteristic of India’s climate is the occurrence of heavy rainfall during the monsoon season. Additionally, other weather systems contribute to significant rainfall. Coastal cities and towns are also vulnerable to storm surges.

Furthermore, the sudden release or delayed discharge of water from dams can have severe consequences.

• Moreover, the Urban Heat Island Effect has led to increased rainfall in urban areas. Global climate change is altering weather patterns, resulting in more frequent high-intensity rainfall events within shorter durations. Additionally, the looming threat of rising sea levels poses a significant risk to coastal cities. Urban areas situated along coastlines, riverbanks, upstream or downstream of dams, in hilly regions, and even inland cities are all vulnerable to these impacts.

• Issues in Urban flooding

Stormwater drainage systems in the past were designed for rainfall intensity of 12 – 20 mm. These capacities have been getting very easily overwhelmed whenever rainfall of higher intensity has been experienced.

Further, the systems very often do not work to the designed capacities because of very poor maintenance.

Encroachments pose a significant challenge in many cities and towns. Natural streams and watercourses have evolved over thousands of years due to the continuous flow of water within their respective watersheds. Over time, human settlements expanded into towns and cities along these rivers and streams, leading to an increase in water flow proportional to urbanization.

Ideally, just as roads are widened to accommodate increased traffic, natural drains should have been expanded to manage the rising volume of stormwater. However, large-scale encroachments on natural drainage channels and river floodplains have occurred instead. As a result, the capacity of these natural drains has significantly decreased, causing frequent flooding.

Additionally, improper disposal of solid waste— including household, commercial, and industrial waste— as well as the dumping of construction debris into drainage systems, has further reduced their efficiency. It is crucial to implement better maintenance and operational measures to address these issues effectively.

Flood Risk Reduction in China

• In China, the reclamation and utilization of lakes, floodplains, and upstream slopes have significantly reduced the capacity to store and discharge floodwaters. Implementing flood control measures has been challenging due to conflicts between local interests and the broader river basin management, leading to inefficient flood operations during flood periods.

• Following the severe flooding event of 1998, China has adopted an integrated approach to water resource and flood management, including:

Formulating water development plans that consider all relevant factors, with a focus on multipurpose use and balancing water utilization for livelihoods, development, and environmental sustainability.

Incorporating water resource development programs into national and social development planning.

Establishing a water management system that integrates river basin management with administrative divisions, primarily provinces.

Prohibiting any construction, infrastructure development, or activities within designated river channel management zones that could hinder flood discharge capacity.

The central government has laid down specific policies for implementation of the above- mentioned laws, comprising:

Restoration of reclaimed areas like slope area, lake area and the flood prone areas to natural forest and lakes with government subsidy;

Relocation of people of these reclaimed areas and economic compensation and tax exemption for the settlers; and

Restraining the economic development and control of the population growth in flood prone areas, especially in frequently flooded areas.

Specific policies to cope with soil and water loss in mountainous and hilly areas include:

Integrated regulation and management of small catchments;

Establishment of a contract system for regulation and management of small catchment in soil eroded areas;

Reinforcement of prevention of soil erosion; and

Establishment of a market-oriented mechanism in soil and water conservation

Urban Flooding Risk Mitigation

Urban Flooding Risk Mitigation Understanding Disaster Risk

• Mapping/ Zoning.

• Estimation of Possible Inundation levels.

• Estimation of Flood Damages.

• Ward level Risk Reduction and Vulnerability Assessment.

• Maximize real-time hydro-meteorological network to cover all urban centers.

• Establish satellite-linked Automatic Rain Gauge Stations, Automatic Weather Stations for 24x7 Weather monitoring

• Coordinate with IMD in setting up of local networks at identified places

• Coordinate with the central agencies

• Hazard Risk Vulnerability Assessment

• Develop Blue Green Infrastructure (i.e. water bodies and parks ), flood walls, Bioswales (along roadsides for water percolation) etc.

Inter-Agency Coordination

• It is required among both central and state agencies in the field of overall disaster governance, Response, Warnings, Information and data sharing and non-structural measures.

Investing in DRR–Structural Measures

• Urban Design

• Airports to be made flood-proof by providing efficient drainage for a much higher rainfall intensity.

• All future road and rail bridges in cities crossing drains to be designed such that they do not block the flows resulting in backwater effect.

• All road re-levelling works or strengthening/ overlay works to be carried out by milling the existing layers of the road so that the road levels will not be allowed to increase.

• Ensure protection of Water Bodies and its restoration/ revival.

• Remove encroachments and take strict action against the encroachers as per the bylaws/ regulations.

• Establishment of Emergency Operation Centres

• Hazard resistant construction, strengthening and retrofitting of all lifeline structures and critical infrastructure.

Investing in DRR–Non-Structural Measures

• Preparation of comprehensive Urban Storm Drainage Design Manual (USDDM)

• Preparation of Storm Water Drainage System Inventory

Operation and Maintenance of Drainage Systems

Environmental Impact Assessment

• To ensure strict compliance of Techno-Legal Regime through ULB

• Constitution of Urban Flooding Cell for Integrated UFDM

• Promote private participation in disaster management facilities.

Capacity Development

• Urban Flood Education and Training

• Ensure accurate documentation of all aspects of disaster events for creating good historical records for future research and mitigation planning.

• Empowering women, marginalized and persons with disabilities by incorporating gender sensitive and equitable approaches in capacity development covering all aspects of disaster management at the state, district and local levels.

• Awareness Generation

• Carry out mass media campaigns

• Promote culture of disaster risk prevention, mitigation and better risk management

•     Promote attitude and behaviour change in the awareness campaigns/ IEC

• Promote use of insurance/ risk transfer

• Promote Community Radio

• Strengthening network of civil society organizations

for awareness generation about DRR and DM.

• Information on care and protection of disaster- affected animals.

• Community-Based Disaster Management

• Strengthen ability of communities to manage and cope with disasters based on a multi-hazard approach

• Training for panchayat, SHG, NCC, NSS, Youth, local community organizations.

• Mock Drills/Exercises

Steps Taken to Mitigate Urban Floods

• Jal Shakti Abhiyan (JSA) in the country in which special emphasis is being given for rainwater harvesting/ groundwater recharge. First JSA was launched in 2019 in water stressed blocks of 256 districts.

• Amrit Sarovar Mission has been launched with an aim of developing and rejuvenating 75 water bodies in each district of the country as a part of celebration of Azadi ka Amrit Mahotsav for rainwater harvesting/recharge.

• Atal Bhujal Yojana involving the local communities at village levels with an outlay of Rs. 6,000 crore, in collaboration with States, in certain water stressed areas of Gujarat, Haryana, Karnataka, Madhya Pradesh, Maharashtra, Rajasthan and Uttar Pradesh. Under Atal Bhujal Yojana, the focus is on demand side management of ground water and accordingly water saving interventions such as use of micro irrigation (drip/sprinkler system), shifting of cropping pattern from high water intensive crops to low water intensive crops, mulching etc. are being encouraged and incentivised.

• Under the Atal Mission for Rejuvenation and Urban Transformation (AMRUT) 2.0 Scheme, provisions have been made for harvesting the rainwater through storm water drains into water body (which is not receiving sewage/effluent) & creation/ strengthening of storm water drains around water body.

• Model Building Bye Laws (MBBL), 2016 for the States/ UTs were formulated by Ministry of Housing & Urban Affairs (MoHUA). As per MBBL, all buildings having a plot size of 100 sq.m. or, more shall mandatorily include the complete proposal of rainwater harvesting. 35 States/ UTs have adopted the features of the Bye Laws.

• Master Plan for Artificial Recharge to Groundwater – 2020: It has been prepared by the Central Ground Water Board (CGWB) in collaboration with States/UTs. The plan aims to construct about 1.42 crore rain water harvesting and artificial recharge structures. Sponge Cities Mission for civic planning

Landslide Risk Mitigation Strategy

Landslide Risk Mitigation Strategy

To carry out the risk mitigation work, a team of cross-sectoral and interdisciplinary professionals which include geologists, engineers, architects, physical planners, public/community, disaster managers, policy and decision makers have to play a proactive role. The mitigation and management strategy must have a combination of features like:

Understanding Disaster Risk

Hazard Zoning

Mapping and Investigations: Conduct geological and geotechnical studies in landslide-prone areas.

Scientific Assessment: Analyze factors contributing to landslides to predict their likelihood and better understand the forces driving them.

Climate Change Impact: Assess how changing climate patterns influence landslide occurrences.

Research and Development: Develop methods to minimize the factors that contribute to landslides.

Hazard Risk and Vulnerability Assessment

Evaluate vulnerability based on social, economic, ecological, gender, and equity aspects.

Assess changes in risk and vulnerability under different climate change scenarios.

Warning Dissemination

Ensure adequate infrastructure and facilities to provide timely access to at-risk communities.

Deliver warnings effectively to all, including remote, rural, and urban populations, with regular updates for those in danger zones.

Monitoring and Early Warning Systems

• Implement effective monitoring, warning mechanisms, and dissemination strategies to mitigate landslide risks.

Investing in DRR–Structural measures

Structural measures are those measures which include physical construction to reduce or avoid possible impact of hazards. These measures include engineering solutions, such as

• Drainage control measures through provisions of surface and subsurface drains.

• Retaining and reinforcement structures.

• Deflection spurs at the toe to avoid erosion from the rivers.

• Landslide treatment methods like shotcreting, grouting, netting, wire-meshes and sealing of cracks / fissures on the hills.

• Adopt remedial techniques like buttresses, shear keys, sub-drains, soil reinforcement etc.

• Construction of retaining walls, afforestation, terrace farming.

Investing in DRR–Non-Structural Measures

Non-Structural Measures are all such measures where efforts are made to mitigate the impact of landslides without construction of disaster resistant features. Methods may include:

• Hazard Mapping and Effective Land Use Planning: Landslide hazard maps help identify high-risk areas, preventing the development of settlements in these zones. Such regions should ideally be reserved for permanent vegetation to maintain stability.

• Surface Drainage Management: Implementing surface drainage control measures reduces water infiltration during heavy rainfall, limiting landslide movement. Reforestation efforts aid in stabilizing the topsoil, preventing erosion and runoff, thereby reducing landslide risks.

• Landslide Monitoring and Early Warning: Continuous monitoring of landslide-prone areas enables early detection of potential disasters, allowing timely warnings to be issued to at-risk populations.

• Engineering Solutions: The construction of protective structures such as retaining walls, rock bolting, piling, and net installations helps mitigate landslides by reinforcing slopes and preventing debris movement.

• Community Engagement and Public Awareness: Encouraging local participation and spreading awareness about sustainable development and landslide mitigation techniques through collaboration with local authorities and non-governmental organizations.

• Afforestation in Vulnerable Areas: Planting suitable vegetation in landslide-prone regions can help stabilize the soil and reduce the risk of landslides to a certain extent.

• Education and Awareness Initiatives: Educating and raising awareness among residents living in landslide- prone areas to enhance preparedness and risk reduction.

Capacity Development

• Training for Professionals: Equip experts with the skills to manage slope failures, landslide remediation, and emergencies by encouraging the use of observational design and construction methods, along with training in contingency planning.

• Mass Media Awareness Campaigns: Utilize media platforms to spread awareness and educate the public on landslide risks and safety measures.

• Promote a Culture of Disaster Risk Reduction: Encourage proactive disaster prevention, mitigation strategies, and effective risk management practices.

• Encourage Community Radio: Utilize community radio to disseminate critical information and updates on disaster preparedness.

• Multi-Institutional Collaboration: Establish multi- disciplinary teams for on-site landslide investigations, document lessons learned, and share findings for better preparedness.

• Enhancing Community Resilience: Strengthen community capacities to manage and respond to disasters using a multi-hazard approach.

• Training for Local Groups: Provide disaster management training for panchayat members, self-help groups (SHGs), National Cadet Corps (NCC), National Service Scheme (NSS) volunteers, youth, and local organizations.

More Measures to Control Landslides include

• Micro Zonation so as to regulate settlements in hazard prone areas,

• National Landslide Risk Mitigation Strategy 2019

• Landslide Risk Mitigation Scheme

• National Guidelineson     Landslidesand     Snow Avalanches

• Landslide Atlas of India

• National Landslide Susceptibility Mapping

• Grow fuel / fodder trees in all of the common lands.

• Plantation in barren areas, especially on slopes, with grass cover is an important component of Integrated Watershed Management Programme.

• Grazing should be completely restricted. After the area is completely protected from grazing, better grasses can be planted.

Avalanches

Avalanches

The sliding down of snow cover on mountain slope causes avalanches.

Avalanches may occur due to a combination of factors such as the slope of the mountain, depth of snow cover, wind velocity and atmospheric temperature,

vibrations caused by gunfire and strength of resisting forces like vegetation cover of trees and shrubs.

When the balance between the gravitational force of snow cover and the resisting force of the slope and the anchoring effect of shrubs are lost, avalanches are caused.

Avalanches pose significant challenges for local authorities by obstructing roadways, disrupting communication networks in critical areas, and affecting winter sports, leaving tourists stranded in regions with limited facilities. Additionally, small rivers may become blocked, increasing the risk of downstream flooding.

The higher altitudes of the Himalayas experience persistent snowfall, making them prone to avalanches. These regions are also popular for adventure sports. Severe snow avalanches frequently impact Jammu & Kashmir, Himachal Pradesh, and the hills of Western Uttar Pradesh. Approximately 20,000 residents in Nubra and Shyok valleys, along with mountaineers and trekkers, are vulnerable to these hazards due to steep terrain. The Kashmir avalanche of 2005, which resulted in 278 fatalities, mostly among those residing in temporary winter shelters, is a notable example.

An avalanche occurs when the gravitational force surpasses the mechanical strength of the snow cover. These events are triggered by both natural and human- induced factors.

Mitigation Measures for Avalanches

Mitigation Measures for Avalanches

• Avoiding construction of buildings for winter occupancy.

• Avoid construction of power lines, highways and railroads. It they must be constructed then design for minimum impact.

Forecast avalanche, by studying Snow deposition data, heat input, slope angle, by using Remote sensing technology & satellite imagery.

• Only allow agriculture and recreational activities during summer and spring.

• Use explosives to create smaller, controlled avalanches and thus avoid building up of snow for large unpredictable destructive avalanches.

• Quick response teams (QRT) from local administration and NDRF, with standard Avalanche equipment and devices like GPS, Radio Beacons, shovels and sniffer dogs.

Some structural and non-structural measures include:

• Structural measures:

• Planting (Avalanche Prevention Forest)

• Stepped Terraces

• Avalanche Control Piles

• Avalanche Control Fence

• Suspended Fences

• Snow Cornice Control Structures

• Protection structures such as stopping, deflecting and retarding structures.

• Non-structural measures - removing snow deposits on slopes by blasting, predicting avalanches and evacuating people from vulnerable areas.

Heat Waves and Urban Heat Island

Heat Waves and Urban Heat Island

• A heat wave refers to an extended period of unusually high temperatures, exceeding the normal maximum levels typically observed during the summer months in the northwestern regions of India.

• Heat waves generally take place between March and June, though in rare instances, they may persist until July. This extreme rise in atmospheric temperature can cause physiological stress, which in severe cases may lead to fatalities.

•
As per the World Meteorological Organization, a heat wave is characterized by a stretch of at least five consecutive days where the maximum daily temperature surpasses the average maximum temperature by at least five degrees Celsius.

• The Indian Meteorological Department (IMD) has given the following criteria for Heat Waves:

• A heat wave is identified when the maximum temperature of a location reaches at least 40°C or more in plains, 37°C or higher in coastal areas, and a minimum of 30°C in hilly regions.

• If a location’s normal maximum temperature is 40°C or below, a heat wave is declared when the temperature deviates by 5°C to 6°C from normal

• Severe heat wave is recorded when the deviation reaches 7°C or more.

• If the normal maximum temperature exceeds 40°C, a heat wave is considered when the deviation is between 4 C and 5 C, whereas a severe heat wave occurs with a deviation of 6 C or more.

• Regardless of the normal maximum temperature, a heat wave is officially declared when the actual maximum temperature reaches or exceeds 45°C.

• The frequency, intensity, and duration of heat waves are increasing globally due to climate change, leading to more extreme daily peak temperatures.

Mechanism of Heat Wave Development

• Heatwaves are generally the result of trapped air. Heatwaves form when high pressure aloft (3000-7000) metres strengthens and remains over a region for several days up to several weeks.

High-pressure systems force air downward. This force prevents air near the ground from rising. The sinking air acts like a cap it traps warm ground air in place.

• This high concentration of pressure makes it difficult for other weather systems to move into the area which is why a

heatwave can last for several days or weeks.

• The high-pressure inhibits winds and also prevents clouds from entering the region

• The end result is a continual build-up of heat at the surface that people experience as a heat wave.

India too is feeling the impact of climate change in terms of increased instances of heat waves which are more intense in nature with each passing year, and have a devastating impact on human health thereby increasing the number of heat wave casualties. In India, the five most severe heatwave events have occurred after 1990.

Health Impacts of Heat Waves

The India Meteorological Department (IMD) has developed a Heat Index that categorizes heat levels using color codes: Green for temperatures below 35 C, Yellow for 36-45 C, Orange for 46-55 C, and Red for temperatures exceeding 55 C.

Health Effects of Heat Waves: Exposure to extreme heat can lead to various health issues such as dehydration, heat cramps, heat exhaustion, and heat stroke. The symptoms associated with these conditions are:

Heat Cramps: Swelling (edema) and fainting (syncope),

often occurring with a fever below 39 C (102 F).

Heat Exhaustion: Symptoms include fatigue, weakness, dizziness, headaches, nausea, vomiting, muscle cramps, and excessive sweating.

Heat Stroke: A life-threatening condition characterized by a body temperature of 40 C (104 F) or higher, along with symptoms such as confusion, seizures, or coma.

Heat Wave of 2023: Severe heat waves in Uttar Pradesh and Bihar resulted in nearly 100 fatalities.

    Map: Heat Wave Prone Areas of India    

• Strengthening and maintaining monitoring and data

Heat-wave victims are the poor and vulnerable

The casualties of heat-wave conditions were mostly the poor and vulnerable in the unorganized sectors, such as daily-wage laborers, street hawkers, etc. They are compelled to work outdoors out of economic necessity, to earn their livelihood. Being unable to avoid the outdoors, they are particularly vulnerable to the dangers of heat-wave conditions.

Heat-waves mean tragedy and loss for both families and nation Heat-wave deaths and illnesses mean tragedy and loss, not only for the families of the victims, but also for the nation, for whom any avoidable loss of life is lamentable. Deaths and illness also mean productivity loss for the nation.

Mitigation Measures for Heat Wave

Mitigation Measures for Heat Wave Understanding Risk

• Vulnerability Assessment and Establishing Heat-Health Threshold Temperatures

logging systems for temperature, humidity, etc. required for threshold for heat wave alerts.

• Establish and maintain community -based network for sharing alerts

• Modify or customize warnings according to thresholds suitable for the State/UT

• Hazard Risk Vulnerability and Capacity Assessment (HRVCA)

• Create awareness preventive measures

• Specific messages for highly vulnerable groups such as elderly, young children, outdoor workers and slum residents

• Systematic data management on disaster damage and loss assessments

Inter-Agency Coordination

• Overall Disaster Governance

• Establishing and reinforcing the institutional framework, including designating a nodal agency and officials at various levels.

• Developing region-specific Heat Action Plans tailored to state or local requirements.

• Organizing response teams and enhancing coordination mechanisms for efficient management.

• Incorporating technical expertise and best practices from different regions for effective implementation.

• Partnering with NGOs to strengthen outreach and support efforts.

• Preparation and Response

• Managing and coordinating an immediate response to heatwave conditions.

• Collaborating with central agencies for effective action.

• Setting up First Aid and Medical Aid facilities at key locations.

• Identifying high-risk areas and ensuring access to drinking water at vulnerable sites and workplaces.

• Suspending outdoor sports and recreational activities during extreme heat.

• Ensuring livestock preparedness by providing adequate shade and water during hot weather.

• Establishing medical assistance points at locations with large gatherings.

• Implementing a Heat Alert System to facilitate early morning shifts for schools and offices, or rescheduling their timings during heatwave periods.

• Constructing cool shelters, shaded bus stands, and other infrastructure to provide relief from extreme heat.

Warnings, Information, Data

Coordinating the dissemination of warnings to all, down to the last mile – remote, rural or urban; Regular updates to people in areas at risk

Follow the alerts/warning

Collecting Data/Information necessary for review/ update of the plan

Investing in DRR – Structural Measures

Directive to promote cool roofs and heat reducing integrated development, passive cooling technology.

Guidelines and technical support for incorporation of protection from heat wave in Multi-Hazard Resistant Housing Schemes and Heat Wave Action Plan

• Hazard resistant construction, strengthening, and retrofitting of all lifeline structures and critical infrastructure.

Investing in DRR – Non-Structural Measures

• To reduce heatwaves, we will need to modify our urban planning standards and building bylaws to enhance green areas and water bodies and promote cool roofs and green buildings, among other things.

•
Techno -Legal regimes

• Laws and Regulations

• Institutional arrangements

• Improving the forest coverage and green areas

• Promote use of building materials that provide protection from heat

• Promote designs to reduce heat island effects in urban areas

• Facilitate integrated development plans that can cope better with heatwave conditions

• Implementationof        Risk    TransferArrangements    

including multi-hazard insurance for life and property.

Capacity Development

• Train key officials regarding pre, during and post heat- wave season activities

• Training for deployment of Rapid Medical Response Teams

• Training on heat-wave specific health care for vulnerable groups

• Inclusion of heat wave and similar issues in various curriculum

• Promoting awareness, alertness and preparedness

• Promoting the planning and execution of emergency drills

• Promoting skill development for hazard resistant construction with emphasis on protection from heat in heat-wave prone areas for different types of housing and infrastructure.

• AHeat Code will outline the criteria for declaring heatwaves and will develop Standard Operating Procedures (SOPs) to be used during heatwaves, such as work-hour limits and relief measures in public places and hospitals. The heat code will also give the district administration the authority to declare an emergency, halt outdoor activities, and allocate resources for heat relief.

Heat Island Effect

Heat Island Effect

At nights, cities are often hotter than the suburbs or the countryside. They become ‘islands’ of higher temperature within a larger rural landscape, in a phenomenon called the Urban Heat Island Effect.

For smaller cities, heat islands are less noticeable. For a large city of one million people, the average temperature can be anywhere from around 1°C to 12°C warmer than the surrounding area.

There are three basic types of heat islands:

Canopy layer

Boundary layer

Surface

• Both Canopy Layer and Boundary Layer heat islands refer to atmospheric heating (warmer air temperatures).

• Surface Heat Islands refer to the actual temperature of surfaces in a specific heat island.

• Although the timing and intensity of these types may vary, they can all be harmful to urban and suburban environments.

    Figure: Heat Island Phenomena    

• A 2020 study temperature data of 44 large Indian cities by IIT Kharagpur suggests that urban areas are taking longer to shed heat, despite having greenery in surrounding rural or suburban areas.

• There is a slow and consistent increase in the background temperature of cities– a signature of human-caused global warming and local climatic changes. Evidence from the study suggests that more green spaces within the city’s boundary could reduce the temperature in the city and outlying areas.

What Causes the Heat Island Effect?

• Loss of Vegetation and Surface: When urban and suburban areas lose land surface and naturally occurring vegetation, heat can no longer easily escape. Loss of tree cover in cities allows much less cooling of the area through evapotranspiration – a combination of evaporation (movement of water to air from surfaces such as soil, water bodies, etc.) and transpiration (movement of water through plant roots into the air via tiny pores in leaves called stomata).

• Geometric Effects: Buildings, especially tall ones, provide multiple surfaces that reflect and absorb heat from sunlight. In addition, multiple tall buildings in close proximity to each other also act as barriers to air flow and wind, which block cooling by convection. These two factors together lead to the Urban Canyon Or Street Canyon Effect, which blocks the loss of heat from ground surfaces through radiation.

• Dark Surfaces and Thermal Bulk Properties: Asphalt (roads) and concrete (most buildings) absorb much

more heat than surrounding rural areas. Concrete, which is has a very high heat capacity. In addition, atmospheric conditions above cities often lead to urban air being trapped near the ground surface, where it is heated by the warm urban surfaces.

• Anthropogenic Heat Generation and Air Pollution: Anthropogenic heat is produced by vehicles and buildings (through electric devices like fans, computers, refrigerators, and air conditioners), almost negligible in commercial and residential areas, yet high levels of air pollutants in cities, however, especially carbon dioxide and ozone, both of which are greenhouse gases, are thought to contribute significantly to the UHI effect.

• Waste heat from energy use is another source of additional heat.

• Other contributing factors include local weather, seasonal changes, time of day, and geographic location.

What are the Implications of Heat Islands?

• Heat islands are considered a form of local climate change as opposed to global climate change. The effects of heat islands are confined to specific areas.

• Of course, one of the most noticeable impacts on urban dwellers is an increase in hot, summer weather, inhabitants of larger cities will notice hotter and more uncomfortable temperatures. New York City has been called a “floating oven”.

• High use of air conditioners results in more heat being released into the air, this also contributes to air pollution, as more greenhouse gas emissions are discharged. This

negatively impacts air quality and can also lead to a

surge in urban smog.

• It can lead to problems such as asthma, increased spread of vector-born disease, heat stroke, and childhood obesity. The city of Toronto averages about 120 deaths per year. Heat Exhaustion, Heat Syncope (Fainting) and even death can occur among residents.

Mitigation of Heat Island Effect

• One popular technique for combatting the heat island effect is installing green roofs on urban buildings.

• Green roofs, which are lined with soil and certain types of vegetation, can actually help cities regain some of the cooling and evaporative effects that the natural landscape once provided.

• As this idea becomes more popular, there is more and more scientific evidence that green roofs can reduce heat in urban areas.

• Paint buildings with light or white colours that do not absorb nearly as much heat.

• Another rooftop technique is Roof Sprinkling. As moisture from the sprinklers evaporates, this helps to cools the surrounding air.

• Many cities have urban forestry initiatives like Green Ribbon technique of Toronto.

• Promoting the use of coatings with high reflectance and emittance (ability to emit absorbed heat quickly) to reduce heat absorption in buildings.

• Non-roof-based strategies:

• Focus on increasing vegetation cover in cities by planting trees in open areas (especially places such as parking lots which are usually asphalted).

• Promoting ‘green walls’ (vertical plant growth systems).

• Other ideas involve increasing numbers of water bodies, and the use of ‘climate-responsive’ architecture, using specific materials and ventilation techniques that promote passive cooling such as the Tube House in Ahmedabad.

Linkages between Heat Waves, Urban Heat Island Effect and El Nino

• Under the background of global warming, interaction between heat waves (HWs) and urban heat island (UHI) has led to trends of increase in the intensity, frequency, and duration of extreme heat events in urban areas, seriously threatening the health of urban populations.

• This effect increases energy costs (e.g., for air conditioning), air pollution levels, and heat-related illness and mortality.

• While both urban and rural dwellers are affected by heat waves, typically, temperatures in cities can be 5-8 C higher than those in surrounding rural areas due to this.

• Another factor of El Niño will greatly increase the likelihood

of breaking temperature records and triggering more

extreme heat in many parts of the world and in the ocean.

Steps Taken for Heat Waves

• Fortunately, many cities and states have acknowledged the threat and developed Heat Action Plans (HAPs). For example, in 2013, Ahmedabad became the first city to implement a HAP to raise public awareness, identify high-risk groups, issue heatwave alerts, and improve inter-agency collaboration. So far, 30-odd cities have adopted similar HAPs.

• State-wide HAPs have also been introduced in Delhi,

Tamil Nadu, Kerala, Maharashtra, and Odisha.

• In 2015, Government of India declared heatwave a natural disaster under the National Disaster Management Act of 2005.

• As a result, while the heatwave is qualified for support from the National and State Disaster Response and Mitigation Funds.

• However, there are insufficient resources and capacity to enhance resilience in cities and states.

• Also nationally, the overall effort remains grossly inadequate.

• Our existing building codes and urban planning are not intended to keep our cities cool. On the contrary, they are worsening heatwaves by magnifying the Heat Island Effect.

• Fortunately, many cities and states have acknowledged the threat and developed Heat Action Plans (HAPs). For example, in 2013, Ahmedabad became the first city to implement a HAP to raise public awareness, identify high-risk groups, issue heatwave alerts, and improve inter-agency collaboration. So far, 30-odd cities have adopted similar HAPs.

• State-wide HAPs have also been introduced in Tamil

Nadu, Kerala, Maharashtra, and Odisha.

• In 2015, Government of India declared heatwave a natural disaster under the National Disaster Management Act of 2005.

• As a result, while the heatwave is qualified for support from the National and State Disaster Response and Mitigation Funds.

• However, there are insufficient resources and capacity to enhance resilience in cities and states.

• Also nationally, the overall effort remains grossly inadequate.

• Our existing building codes and urban planning are not intended to keep our cities cool. On the contrary, they are worsening heatwaves by magnifying the Heat Island Effect.

• The Ministry of Health and Family Welfare has taken steps to increase public awareness on the subject of health impacts of climate change including heat waves, under the ‘National Programme on Climate Change and Human Health’.

Cold Wave and Frost

Cold Wave and Frost

• Cold waves and frost are seasonal, localized hazards that affect specific regions of the country experiencing harsh winters. Frost occurs when ice crystals form on surfaces due to a prolonged drop in nighttime temperatures.

• The northern parts of India, particularly the hilly areas and nearby plains, are impacted by transient disturbances in the mid-latitude westerlies, commonly known as Western Disturbances, which often exhibit weak frontal characteristics.

• Cold waves primarily impact regions north of 20°N, but under large amplitude trough conditions, states likeMaharashtra and Karnataka have also reported cold wave occurrences.

• The vulnerability of crops to frost varies significantly, and the severity of damage depends on temperature, duration of exposure, humidity levels, and the rate at which freezing temperatures are reached.