A stampede refers to a collective and chaotic rush of movement where a large group runs together without coordination, typically driven by a shared instinct to flee from a perceived danger.

Major Stampede Disasters in India

Stampede disasters include 

• Uphaar Cinema ’97
• Sabrimala stampede ’99
• Railway Station Allahabad ’13 
• Elphinstone Bridge Mumbai ’17 

Structural factors and poor crowd control measures lead to stampedes.

1. Structural Factors  

• Insufficient exits, narrow passageways, and poorly designed venues can impede the flow of people during events or emergencies, increasing the risk of stampedes.

2. Poor Crowd Management

• Underestimation of the audience 
• Crowd Behaviour: The influx of people in a gathering that triggers a stampede occurs when individuals perceive a threat or a lack of personal space. This disruption frequently hampers the organized flow of the crowd, resulting in chaotic and hazardous movements driven by the instinct to protect oneself. As a consequence, injuries and even deaths can occur.  

3. Panic and Fear

• Stampedes can be triggered by panic and fear within the crowd. Factors such as sudden loud noises, rumours of danger, or perceived threats can create a sense of panic, causing people to rush and trample over each other in an attempt to escape the perceived danger. 

4. Poor coordination between Stakeholders

• Stampede can happen due to a lack of understanding of the range of duties entrusted, communication delays, coordination gaps between agencies etc. 

Note: Deaths from stampedes occur primarily from compressive asphyxiation. 

Stampede is closely associated with the concept of Crowd Management.

Crowd management is a strategy employed to maintain public safety by effectively handling and controlling large gatherings, aiming to avoid incidents such as stampedes, conflicts, violent clashes, uprisings, or dispersing assemblies, protests, or demonstrations.

The dynamics of crowds consist of a blend of voluntary and involuntary influences. 

• When the density of a crowd is properly regulated, individuals within it are primarily influenced by voluntary forces.
• But when the crowd density exceeds a critical threshold, people’s movements are compelled by involuntary forces, which involve physical pressures exerted by pushing from behind, the sides, or other directions in tightly packed circumstances. During stampede, involuntary forces are dominant.

According to NDMA guidelines 

• Risk Analysis and planning should be the first step. All event organizers should conduct a Failure Mode and Effect Analysis (FMEA). 
• Information management dissemination is crucial. The absence or poor information management in itself may be a source of crowding.  
• Capacity Planning (Long term and Short term): It emphasizes the need to develop infrastructure based on popularity, periodicity of the event, weather, terrain and local population. 
• Understanding Crowd Behaviour: The behaviour of an individual in a crowd is influenced by the behaviour of others. The unlawful actions of a few people can result in a larger number following them. 
• Crowd control-The guiding principle for crowd control should be managing the demand-supply gap by controlling the crowd inflow, regulating the crowd at the venue and controlling the outflow if needed. 
• Stakeholder approach-organizers/law enforcement agencies must encourage community stakeholders (NGOs, Business Associations, Schools/Colleges, neighbourhoods, societies. Mohall committees etc.) to take ownership in events to uphold unity of purpose, faster decision/response, better coordination etc.  
• Training: Training crowd management personnel, providing instructions on normal and emergency crowd movement and conducting mock drills is essential to prevent crowd disasters.
• Technology: Use of Technology like remote sensing, GIS etc., to improve the crowd experience and crowd control.

The sudden release of energy in Earth’s crust, which leads to a series of motions due to waves created by the released energy, is called Earthquake. 

• Tectonic Activity: The Himalayas are still evolving and adjusting to ongoing tectonic movements. The collision between the Indian plates and Eurasian tectonic plates creates immense pressure, resulting in frequent seismic activity in this region. The Himalayas are considered one of the most earthquake-prone regions in the world.

• Gulf of Khambhat and Rann in Western Gujarat: The movement of the Arabian Plate against the Indian Plate contributes to seismic events.
• Parts of Peninsular India, particularly along the Bhima Fault represented by the river Bhima near Latur, also experience significant seismic activity.
• The islands of Lakshadweep and Andaman and Nicobar Islands are prone to earthquakes due to their proximity to major tectonic boundaries.

Some Great Earthquakes occurred in India.

• Disaster Preparedness is most important in case of Earthquakes because it can save a lot of lives. 
• The most devastating earthquakes in terms of casualties are not necessarily the ones with the highest magnitudes on the Richter scale. Other factors, such as population density, building infrastructure, and preparedness levels, play a significant role in determining the outcome of an earthquake. The Haiti earthquake of 2010, measuring 7 on the Richter scale, serves as a tragic example. It claimed the lives of approximately 316,000 people due to a combination of factors, including a densely populated area and insufficient preparedness measures. 

1. Disaster Risk Reduction (Before Earthquake)

1.1 Earthquake Resistant Buildings

• Earthquake Resistant Buildings: Constructing buildings that can withstand seismic forces is crucial. Currently, around 80% of houses in India are not Earthquake resistant. Enhancing building standards and promoting earthquake-resistant construction techniques can significantly reduce casualties 
• In the Bhuj Earthquake of 2001, RC buildings collapsed just an Earthquake of 7 on the Richter scale when RC buildings should stand up to 7.5

1.2 Seismic Codes

•  India has a range of seismic codes that provide guidelines for constructing earthquake-resistant structures. However, enforcement of these codes is often lacking. Strengthening the implementation and enforcement of seismic codes is necessary to ensure the safety of buildings. 

1.3 Early Warning Systems

• Developing and implementing early warning systems can provide valuable seconds to minutes of advance notice before an earthquake strikes. These systems use sensors to detect seismic waves and issue alerts, allowing people to take immediate protective actions and evacuate if necessary. 

1.4 Preparing Vulnerability Maps

• Creating vulnerability maps of earthquake-prone areas can help identify higher-risk regions and guide decision-making processes. 

1.5 Educating People on How to Respond

• Conducting mock drills and training sessions in highly vulnerable areas can educate people on earthquake response strategies. 

2. Disaster Response (During Earthquake)

2.1 Fast Response 

• The time window for rescuing survivors after an earthquake is often narrow. Prompt response by emergency services is crucial. Establishing effective communication channels, coordinating rescue efforts, and deploying trained personnel quickly can increase the chances of saving lives.

2.2 Rescue Operations

•  Immediate focus should be on clearing debris and locating individuals who are trapped or in need of help. Efforts should be made to find and extract survivors efficiently using specialized equipment and search-and-rescue techniques.

2.3 Relief

• Providing temporary shelters, medical assistance, and essential supplies to injured individuals is essential. Ensuring that relief camps maintain proper hygiene standards is important to prevent the spread of diseases and minimize casualties. 

3. Recovery and Rehabilitation (After Earthquake)

3.1 Build Back Better

• Build Back Better: After an earthquake, reconstruction efforts should aim to “build back better.” It involves incorporating seismic-resistant design principles and construction techniques in the rebuilding process. Learning from successful examples, like the reconstruction programs in Bhuj, India, can help create models for earthquake-resistant construction in other affected areas.

3.2 Psychological Services

• Earthquakes can cause immense psychological trauma for those who have lost loved ones or witnessed the destruction. Providing psychological support services to affected individuals can aid in their recovery and help them cope with the emotional impact of the disaster.  

Japan is located in a seismically active region known as the Pacific Ring of Fire, making it highly prone to earthquakes. Over the years, Japan has developed an exemplary model of earthquake management that combines proactive measures, technological advancements, and public awareness. 

1. Earthquake-Resistant Buildings: Japanese engineers and architects have devised innovative techniques and building codes to ensure structures can withstand seismic forces.
2. Mock Drills: Regular mock drills are crucial in preparing Japanese citizens for earthquake emergencies. These drills are conducted at various levels, from schools and workplaces to entire communities. 
3. Research and Development: Japan has established the Institute for Earthquake Research, an institution dedicated to studying earthquakes and developing cutting-edge technologies for earthquake management

• Avalanches refer to the sudden and rapid sliding down of snow or ice on a mountain slope.

• Currently, avalanches have gained substantial importance, particularly in the regions of Leh and Siachen. These areas have witnessed a significant increase in the frequency of avalanches, leading to tragic and frequent loss of lives. The extreme conditions in these regions and the unique topography and weather patterns make them prone to avalanches. As a result, the lives of Army personnel on duty are continuously at risk.

Some Examples

Avalanches may occur due to a combination of various factors, with each contributing to the likelihood and severity of such events. Some of the key factors include:

1. Global Warming: Global Warming is a significant factor influencing the occurrence of avalanches, particularly in recent times. Rising temperatures lead to changes in glacier characteristics, such as increased water content and altered stability, making slopes more prone to avalanches. 
2. Slope of the Mountain: The steepness and angle of the mountain slope play a crucial role in determining avalanche susceptibility. Steeper slopes generally have a greater potential for avalanches.
3. High Wind Velocity: Strong winds can significantly impact snow distribution and stability, contributing to avalanche formation.
4. Vibrations Caused by Gunfire: Vibrations generated by gunfire or explosive activities can trigger avalanches. 
5. Strength of resisting forces: 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. 

The aftermath of an avalanche can be devastating, leaving behind a trail of destruction and impacting various aspects of life in the affected areas.

1. Loss of Life: Avalanches can cause significant loss of life. Tragically, they can hit or bury human settlements. For instance, the Kashmir avalanche of 2005 claimed the lives of approximately 250 individuals. 
2. Disruption of Transportation: Avalanches can block or destroy roads, making them impassable.
3. Stranded Tourists: In popular tourist destinations located in mountainous regions, avalanches can pose a significant risk to visitors. When a major avalanche occurs, it can strand tourists in remote areas with limited facilities.
4. Blockage of Small Rivers: Avalanches can also block small rivers or creeks due to the sheer volume of snow and debris. This blockage can lead to water accumulation upstream, creating the potential for downstream flooding. 

These consequences highlight the need for preparedness.

Various mitigation measures can be implemented to minimize the risks associated with avalanches. 

Structural Measures

• Planting (Avalanche Prevention Forest): Creating an Avalanche Prevention Forest involves strategically planting trees around settlements or vulnerable areas to serve as a protective cover. 
• Avalanche Control Fence: Avalanche control fences are physical barriers designed to intercept and control the movement of snow during an avalanche event.

Non-structural Measures

• Removing snow deposits on slopes by blasting: Controlled blasting technique to trigger small avalanches and remove accumulated snow deposits from slopes before they become unstable.
• Early Warning System: This system utilizes various monitoring technologies such as snowpack sensors, weather stations, and remote sensing to detect signs of potential avalanche conditions. India has still not installed Early Warning System, although Snow and Avalanche Study Establishment (SASE) is working on this.
• While traveling in snow mountains, Wear an avalanche rescue beacon that signals your location.

By combining both structural and non-structural measures, communities and authorities can significantly reduce the risks associated with avalanches. 

• With its vast coastline spanning approximately 7,500 kilometres, India is frequently affected by cyclones. The country experiences a significant share of the world’s tropical cyclones, accounting for nearly 10% of the global total.
• The east coast of India is more susceptible to cyclones compared to the west coast. The Bay of Bengal, adjacent to the east coast, acts as a breeding ground for cyclones due to its warm waters and favourable atmospheric conditions. Hence, states such as Andhra Pradesh (AP), Odisha, Tamil Nadu, West Bengal, and the union territory of Puducherry, located along the east coast, face a higher risk of cyclonic activity. 
• The west coast of India, although generally less prone to cyclones, also has its vulnerable areas. Gujarat is considered the most susceptible state on the west coast. The Arabian Sea, which borders the western region, can occasionally witness cyclonic disturbances threatening Gujarat and its coastal areas. 

The Super Cyclone and Phailin Cyclone case studies show the importance of preparedness.

Super Cyclone (Odisha, 1999) 

• Wind speeds of 270-300 km per hour  
•  10,000 people killed and lakhs of livestock population. 
• Over 2 million houses were damaged.

But this damage could have easily been reduced.

Cyclone Phailin (2013)

• Early Warnings were given to residents near Bhubaneshwar about an impending Cyclone which struck within a week 
• Casualties were just 50 people dead 

Recent Cyclone Varda in Tamil Nadu & Cyclone Hudhood also showed a similar trend with a death toll not exceeding 10. But the damage to infrastructure is still high. Now reaching the next level, the concern is how to address losses occurring to property – roads, bridges, housing, hospitals, electricity etc. (Note: Sendai calls for a reduction in mortality and the destruction of infrastructure).

• Human loss: Cyclones can have a devastating impact on human lives, leading to loss of life, injuries, and displacement. In India, the 1999 Super Cyclone (Odisha) caused over 10,000 deaths and affected millions of people. 
• Economic Impact: Cyclones can cause significant economic losses. For instance, Cyclone Amphan, which hit India and Bangladesh in 2020, caused an estimated economic loss of around $13 billion. 
• Loss of Livelihood: Coastal communities often bear the brunt of cyclones. In India, the communities dependent on fishing face severe challenges during cyclones. For example, in the aftermath of Cyclone Phailin in 2013, fishing was prohibited in coastal areas of Odisha, impacting the livelihoods of thousands of fishermen and their families. They lost access to food and clean drinking water and suffered from a loss of income.
• Structural Damage: Cyclones can cause extensive damage to infrastructure, including roads, bridges, buildings, and other public facilities. Hurricane Katrina, 2005 in the United States, is a notable example of the significant structural damage caused by a cyclone.
• Floods: Cyclones often bring heavy rainfall, leading to widespread flooding. It can result in the displacement of communities, damage to homes and infrastructure, and the spread of waterborne diseases.
• Agricultural Damage: Cyclones can have a detrimental impact on agriculture, causing the destruction of crops and farmland. Cyclone Nargis, which struck Myanmar in 2008, caused extensive damage to the country’s agriculture sector, resulting in food shortages and increased vulnerability for the population.

• The Indian Cyclone Early Warning System is an advanced meteorological system managed by the Indian National Centre for Ocean Information Services (INCOIS), which operates under the Ministry of Earth Sciences. 
• The Indian Cyclone Early Warning System relies on the Doppler Effect to effectively detect and track cyclonic storms.
• India has already installed 6 Doppler Radars on the East Coast, which is more vulnerable to the Cyclones.

• A heat wave refers to a period in the summer months when temperatures rise significantly above the usual maximum temperature.
• Countries declare heat waves differently. Indian Meteorological Department declares a Heatwave when
  • A departure of 4.5 to 6.4 degrees from the normal is considered a heat wave, while a departure above 6.4 degrees C is considered a severe heat wave.  
  • If the normal temperature of the station is more than 45°C (or 37°C at Hill Station), then a heat wave is to be declared irrespective.  

• Heat waves predominantly occur in India between March and June and occasionally, in rare instances, even extend into July. The month of May is the peak period for heat waves in India.

1. In North-Central India

• In North-Central India, heat waves are commonly observed during summer when an area experiences high pressure ( typically formed by Jet Streams). Heat waves occur due to trapped air caused by the downward force of high-pressure systems. This force prevents the air near the ground from rising, creating a cap-like effect that traps warm ground air in place. 
• Loo: The dry and hot westerly winds originating from Baluchistan, central Pakistan, and the Thar Desert play an important role in the occurrence of heatwaves.

2. In Coastal Areas

• Coastal areas near the Bay of Bengal frequently encounter a significant number of heat waves due to a phenomenon known as the Matsuno-Gill Response. This response occurs when the sea surface temperature of the Bay of Bengal decreases, leading to the development of low pressure over the area during summers. Consequently, the absence of sea breeze flowing from the Sea towards the land disrupts the moderating effect on the climate in coastal areas, resulting in the formation of heat waves.

3. In Cities

• Urban areas experience the Urban Heat Island Effect, where cities tend to become hotter due to an abundance of cement and concrete and a lack of tree cover. This effect exacerbates the situation by causing ambient temperatures to feel 3 to 4 degrees Celsius higher than they actually are.

4. Green House Gas (GHG)

• GHGs contribute to the retention of heat in the Earth’s atmosphere. A stronger greenhouse effect reduces the amount of heat radiation from the Earth that can escape into space.

• Heat Stroke and Heat Exhaustion: Heat waves pose a significant risk of heat stroke and heat exhaustion. 
  • Heat stroke occurs when there is continuous and prolonged exposure to high temperatures, leading to symptoms such as nausea and heat cramps. This condition can result in a rapid rise in body temperature, which can be life-threatening if not treated promptly. 
  • Heat exhaustion, on the other hand, is caused by dehydration due to excessive sweating and inadequate water intake during hot weather.
• Risk of Wildfires: Prolonged heat waves can increase the risk of wildfires. As the heat wave continues, the lack of moisture in the environment dries out vegetation, creating ideal conditions for the ignition and spread of forest or brush fires.
• Drought Conditions: Heat waves exacerbate drought conditions. Soaring temperatures during the dry season intensify the impact of water scarcity, affecting millions of people. 
• Prevents Cloud Formation: Heat waves can hinder cloud formation. The hot and dry conditions suppress the formation of clouds, reducing the chances of rainfall. 
• Impacts on Outdoor Workers: Heat waves severely threaten outdoor workers, particularly labourers and poor farmers who have no choice but to work in blistering conditions. These individuals are at a higher risk of heat-related illnesses and fatalities due to prolonged exposure to extreme heat.
• Increased Energy Demands: Sweltering heat waves lead to a surge in energy demand, particularly electricity

Tsunamis are natural phenomena characterized by the occurrence of large waves in the ocean. These immense waves are primarily generated by sudden movements of the ocean floor, which cause a significant displacement of water. 

• Underwater Earthquakes: When an earthquake occurs, particularly if it originates under the ocean or near a coastline, it can lead to the generation of a tsunami. The seismic activity causes the ocean floor to shift abruptly, displacing enormous water. This displacement sets off a series of powerful waves propagating across the ocean, potentially reaching distant shores with devastating consequences.

• Submarine or Terrestrial Landslides: When a significant amount of sediment or rock collapses into the ocean, it displaces water and propagates outward waves.
• Volcanic Eruptions: Underwater volcanic eruptions can cause substantial disturbances to the ocean floor, leading to water displacement and tsunami formation. Similarly, volcanic collapses or explosions on islands or coastal areas can also generate tsunamis as the force of the eruption interacts with the surrounding water.
• Asteroid, Meteor, or Comet Strikes: In rare cases, tsunamis can be triggered by bolide impacts, such as asteroid, meteor, or comet strikes. These celestial bodies possess immense kinetic energy, and when they collide with the Earth’s surface or enter the ocean, they create a tremendous displacement of water, resulting in waves propagating outward, forming a tsunami. 

The phenomenon of a tsunami, typically caused by earthquakes near seismically active areas in the Pacific Ocean, was historically uncommon in India. However, in December 2004, India was struck by a devastating tsunami on its east and west coasts, resulting in significant consequences.

• Waves were  3-10 m high and penetrated 300 metres to 3000 metres inland. 
• Severe damage to life and property => confirmed death toll in India was 12,405 & 5,640 people are still unaccounted for. 
• Maximum damage was observed in areas which destroyed their mangroves, forests & doing illegal mining.
• However, Village Naluvedapathy experienced minimum destruction as they planted trees on the coast. 

The Indian government has shown significant commitment to enhancing its preparedness for tsunamis.

1. Tsunami Early Warning System: The system has been designed to detect and provide warnings within 10 minutes of a submarine earthquake, providing time for the administration to start the evacuation process.
2. Indian National Centre for Ocean Information Science (INCOIS): It is headquartered in Hyderabad and plays a pivotal role. It serves as the central hub from where all the monitoring and analysis of potential tsunami threats are carried out. 
3. High Frequency (HF) Radars: These radars allow for the continuous monitoring of coastal currents, which helps in understanding the behaviour of the ocean currents and identifying any abnormal patterns that could potentially indicate the presence of a tsunami. 
4. Strengthening Infrastructure: India has constructed coastal embankments, sea walls, and tsunami shelters in vulnerable areas to provide safe havens during emergencies.
5. Public Awareness and Education: The Indian government has initiated extensive awareness campaigns to educate coastal communities about the risks and preparedness measures associated with tsunamis through various mediums such as television, radio, print media, and social media platforms along with Community drills, workshops, and training programs.

• Encroachment of Flood Plains, Mangroves, Wetlands, Lakes, etc.: Rapid urbanization has led to the encroachment and destruction of natural water bodies that act as natural buffers against flooding. For example, 
  • Bengaluru: There were 260 lakes in 1960 and 10 now
  • Mumbai: Mangroves and salt pans have been destroyed for constructing high-end residential buildings 
  • Chennai: Encroachment of wetlands and flood plains 
• Unprecedented Rainfall: Indian cities experience heavy rainfall during the south-west monsoons. The average monthly rainfall in Mumbai in July is 868 mm. Such intense rainfall events overwhelm the drainage systems and cause urban flooding.
• Cyclones and Hurricanes: India’s extensive coastline exposes it to tropical cyclones. The development of coastal cities and towns makes them vulnerable to inland flooding and storm surges caused by cyclones.
•  Unpreparedness in Urban Planning: Many cities lack adequate urban planning and infrastructure to handle urban floods. Unlike cities like Tokyo, which have invested billions in building water discharge tunnels and advanced drainage systems, Indian cities often lack such preparedness.
• Concretization of Cities: The extensive use of concrete and asphalt in urban areas reduces land permeability. It prevents water from seeping underground, increasing surface runoff and exacerbating the risk of urban flooding.
• Urban Heat Island Effect: The phenomenon of urban heat islands, where cities experience higher temperatures than the surrounding countryside, can influence rainfall patterns. The hot air over cities can cause rain-bearing clouds to be pushed up, resulting in highly localized and intense rainfall events.
• Global Warming: Climate change has led to unexpected and extreme changes in rainfall patterns. For instance, Chennai experienced unusually high rainfall in November 2015, with 1200 mm compared to the average of around 400 mm. 

1. Global Examples

1.1 Kuala Lumpur

• Kuala Lumpur, Malaysia’s capital city, has faced significant challenges with urban flooding due to its geographical location and heavy rainfall.
• To address this issue, the city has implemented an innovative solution by constructing extensive water discharge tunnels. Tunnels divert excess floodwater away from the city’s densely populated areas. By creating an alternative pathway for water to flow, these tunnels alleviate the burden on the city’s drainage systems and prevent overwhelming floods.

1.2 Tokyo

• Tokyo constructed a stormwater management system that includes the construction of reservoirs, underground storage facilities, and permeable surfaces to help capture excess rainwater and prevent it from overwhelming the drainage system.
• Tokyo has prioritized the incorporation of green infrastructure, which can absorb rainwater and reduce runoff.
• Installed Early Warning Systems

2. Indian Examples

2.1 Davangere (Karnataka)

Davangere faced recurring urban flooding due to heavy rainfall and inadequate drainage systems. To address this issue, the following was done.

• Improved the city’s stormwater drainage infrastructure 
• Desilted water channels
• Created storage ponds and reservoirs to hold excess water during heavy rains temporarily 

2.2 Agartala (Tripura)

Agartala experienced significant urban flooding due to its geographical location and heavy rainfall patterns. To mitigate the impact of flooding, the city authorities adopted various measures. 

• Construction of flood protection embankments and bunds along vulnerable areas
• Development of rainwater harvesting structures, such as ponds and recharge pits, to capture and store rainwater, thereby reducing the burden on the drainage systems. 
• Improved its sewage and stormwater drainage networks 

1. Standard Operating Procedures (SOP) for mitigating Urban Flooding by the Central Government under the Atal Mission for Rejuvenation and Urban Transformation (AMRUT). It lays down a predefined set of directives or responsibilities for public agencies in a city/town in 3 phases: 

1.  Pre-Monsoon Phase: Preparedness and Planning for Disaster Reduction.  
2. During Monsoon Phase: Early Warning, Effective Response and Management, and Relief planning and execution
3. Post-Monsoon Phase: Restoration and Rehabilitation.

2. Sponge Cities Plan by Urban Local Bodies and State Governments to make cities more permeable. Sponge cities involve the use of porous materials and technologies to improve the city’s capacity to absorb rainwater. E.g. use of permeable material for roads and pavement, contiguous open green spaces, green roofs, etc.

3. National Guidelines on Management on Urban Flooding by the National Disaster Management Authority (NDMA)   

The term “flood” is commonly used to describe a situation where the water flowing in rivers, streams, and other bodies of water cannot be contained within natural or artificial banks. 

Floods occur regularly in India, affecting approximately 10% of the country’s total area. However, the impact and frequency of floods have increased due to climate change.

Natural Causes

• Heavy precipitation: India receives all the rainfall in just 4 months. During that period, the discharge of water in the river increases than the capacity of the river, resulting in floods.
• The river changes its course due to various reasons, such as landslides. By blocking the flow of streams, the landslides cause massive floods.
• Events such as cloud burst, which results in massive water discharge in a very less period
• Climate Change: Climate Change led to increased variability in rainfall patterns, with some areas experiencing prolonged dry spells followed by heavy rainfall in a short period. This change in rainfall patterns contributes to flash floods.

Manmade Causes

• Settlement in Flood Plains: Many towns and cities have been established in floodplains, which are low-lying areas adjacent to rivers and prone to flooding during heavy rainfall or when rivers overflow their banks.  E.g., Construction activities in low-lying areas, such as Alapuzha in Kerala, have made these regions highly vulnerable to flooding.
• Destruction of Natural Wetlands around the Cities: Wetlands play a vital role in controlling floods by acting as natural sponges that absorb excess water during heavy rains. However, the destruction and encroachment of wetlands for urban development and agriculture have significantly reduced their capacity to absorb and store water. 
• Environmental Degradation: The Gadgil report on the fragile ecosystem of the Western Ghats, released in 2011, highlighted the detrimental effects of illegal mining and deforestation in the region. These activities have led to extensive encroachment on river fronts, resulting in reduced river carrying capacity and increased siltation in reservoirs located in the Western Ghats. 
• Deforestation and Soil Erosion: Deforestation, particularly in hilly regions and catchment areas, has a significant impact on flooding in India. Trees and vegetation help to retain rainwater, reduce surface runoff, and stabilize the soil. When forests are cleared for agriculture, urban expansion, or other purposes, the protective cover is lost, leading to higher rates of soil erosion. Increased soil erosion results in more sediment being carried by rivers, leading to siltation and reduced carrying capacity, which in turn contributes to floods.
• Faulty Dam Management: Dam failures, the release of excessive water during heavy rainfall, or sudden discharges without adequate warning can lead to downstream flooding.  The 2018 floods in Kerala revealed shortcomings in dam management. The dam authorities were unable to assess the situation accurately and failed to provide timely warnings to the affected communities.

Flash floods are an extreme manifestation of flooding that takes place within a significantly compressed timeframe, resulting in rapid and intense inundation. Unlike conventional floods that may unfold over a longer period and affect larger regions, flash floods are highly localized. 

Causes of Flash floods in India

1. Cloudbursts: Cloudbursts are sudden, intense rainfall events that occur within a short period in localized areas that overwhelm drainage systems.
2. The concentration of rainfall during the monsoon season: India receives nearly 75 per cent of its total rainfall during the monsoon season. This concentrated rainfall puts a significant burden on the rivers.
3. Water exceeding the Dam’s Capacity: Flash floods can also occur when the water level in a dam exceeds its capacity. 
4. Glacial Lake Overflow: In regions with glaciers, flash floods can be triggered by the overflow of glacial lakes. 

Factors like poor drainage infrastructure, deforestation, and urbanization can also exacerbate the risk of flash floods in certain areas.

Hard Management Techniques

1. Dams: Dams play a crucial role in flood management by trapping and storing water during heavy rainfall or snowmelt periods. The stored water can then be released gradually during dry spells.
2. Embankments or Artificial Levees: These structures are built along riverbanks to contain floodwaters within the river channel, preventing them from spilling into surrounding areas. 
3. Interlinking of Rivers: Connecting rivers through canal systems or diversion channels can help manage floods by diverting excess water from one river to another.
4. Flood Walls/Coastal Defences: These structures are constructed around settlements, particularly in coastal areas, to protect them from the impact of floods and storm surges.  
5. Storage Areas: Constructing temporary storage areas, such as reservoirs or lakes, allows excess water to be pumped out of rivers during flood events.
6. Dredging the River Basins: Dredging involves removing sediments, debris, and vegetation from river channels, increasing their capacity to carry water. 

Soft Management Techniques

1. Washlands: Certain sections of the floodplain, known as washlands, are intentionally allowed to flood. These areas are often designated as sports fields or nature parks, serving as controlled flood zones.
2. Flood Plain Zoning: This technique involves establishing regulations and land-use policies that restrict or discourage development in flood-prone areas.
3. Afforestation: Planting trees and vegetation in flood-prone areas can help manage floods. The roots of trees absorb water and stabilize soil, reducing erosion and the likelihood of flash floods. 
4. Warning Systems: Implementing early warning systems can provide timely information about impending floods.
5. Hydrological Data Sharing: Cooperation and sharing of hydrological data among countries in the upper catchment area of a river basin are vital for effective flood management.

Capacity Building

1. Flood Education: Raising awareness and providing education about floods, their causes, and appropriate responses can empower communities to better prepare and respond to flood events. 
2. Emergency Search and Rescue: Developing specialized search and rescue teams trained in flood response can significantly improve emergency operations. 
3. Emergency Relief: In the aftermath of a flood, providing short-term housing, food, safe water, access to healthcare, and protection for vulnerable groups such as women, children, and the elderly is essential. 

Other Measures

1. There is a need to promote flood-tolerant “scuba rice”, sugarcane, jute and high-value aquatic crops in regions frequently hit by floods. 
2. Formulate Nation-wide Silt Management Policy.