Hailstorms

 Hailstorms

When the water droplets that were about to fall as rain pass through very cold layers of the atmosphere. This will freeze the water droplets, and when these fall to the ground, the phenomenon is known as a hailstorm which is another form of precipitation.Hail forms when a thunderstorm updraft lifts a water droplet above the freezing level in the atmosphere. The frozen water droplet then accretes super-cooled water or water vapor, which freezes once it comes in contact with the frozen droplet. This process causes a hailstone to grow.
Hailstorms may cause 4 injury to human beings, livestock, and can cause damage to standing crops. The probability of occurrence of hailstorms is highest in Maharashtra.

• India, with about 29 hail days of moderate to severe intensity per year, is among those countries in the world which experience a very high frequency of hail. 
• Hailstorms are mainly observed during the winter and pre-monsoon seasons with virtually no events after the onset of the southwest monsoon.
• Hailstorms are classified as
• Slight Hailstorm: If it is sparsely distributed, usually small in size and often mixed with rain.
• Moderate Hailstorm: If it is abundant enough to whiten the ground. 
• Strong Hailstorm: If it includes at least a proportion of large stones. 
• Hailstorms typically last for no more than 15 minutes but can cause injuries to people and damage buildings, vehicles and crops. 
• When hail builds up it can cause a loss of power, bring down trees and cause flash floods and mudslides in steep areas.
• Hailstorms occur frequently in Himachal Pradesh, Jammu-Kashmir Ladakh, Uttrakhand, Haryana, West Uttar Pradesh, and North Rajasthan
• Many States are severely affected by thunderstorms & lightning, squall, dust storms, hailstorm and strong winds during one or the other part of the year with varying frequency.
• A comprehensive preparedness, mitigation and response plan requires the involvement of government authorities, non-governmental organizations (NGOs) and civil society.

Avalanche

 Avalanche

The snow avalanche, a common occurrence in snow covered mountainous regions, is a slide of snow mass down a mountainside. This is a rapid downslope movement of a large detached mass of snow, ice, and associated debris such as rocks and vegetation

• A large avalanche can run for many kilometres, and result in massive destruction of forests and anything else that comes in its way. 
• There are two basic types of avalanches, loose snow avalanches and slab avalanches.
• Loose snow avalanches form in snow masses with little internal cohesion among the individual snow crystals. When such snow lies in a state of unstable equilibrium on a slope steeper than its natural angle of repose, a slight disturbance sets progressively more and more snow in downhill motion.
• Slab avalanches originate in snow with sufficient internal cohesion to enable a snow layer
• A slab avalanche breaks free along a characteristic fracture line 
• A slab release may take place across an entire mountainside
• Slab avalanches are often dangerous, unpredictable in behaviour, and account for most of the damage.
• Avalanches composed of dry snow are called powder snow avalanches
• A wind blast can achieve high velocities, to inflict heavy destruction well beyond the normal bounds of the avalanche path.
• Avalanches form as soon as the force of gravity on the snow cover exceeds its mechanical strength.
• Formation of an avalanches needs 
• a steep slope, 
• snow cover, 
• a weak layer in the snow cover, and 
• a trigger to initiate movement.
• The forces generated by moderate or large avalanches can damage or destroy most man-made structures
• The debris from small avalanches is enough to block a highway or rail-road.
• Where avalanches cross highways, passing vehicles can be swept away and destroyed, killing their occupants

There are two basic methods of anticipating an avalanche hazard. 

1. Examination of the snow cover structure for patterns of weakness, particularly those leading to slab avalanches. 
2. Analysis of the meteorological factors affecting snow depositions. 
3. Rising temperature during a storm accompanied by rising new snow density tends to cause avalanche while falling temperatures have the opposite effect. 
4. New snow precipitation intensity is a significant factor, as it represents the rate at which the slopes are being overloaded.
5. Wet snow avalanches are generated by the intrusion of percolating water (rain or snow melt) in the snow cover. The rapid rise in temperature quickly alters snow behaviour
6. The most extensive wet snow avalanche occurs during winter rains
7. The major inputs for forecasting of snow avalanche are:
1. Snow cover
2. Terrain and 
3. Atmospheric parameters 
8. In order to gather the latest terrain information on avalanche-prone areas, snow cover and atmospheric parameters is gathered by
1. Optical [MODIS, AVHRR, AWiFS, WiFS, LISS-III, PAN, Cartographic Satellite (CARTOSAT), IKONOS, Quickbird] and 
2. Microwave (AMSR-E, SSM/I, Radarsat, ENVISAT) imagery is used
9. Snow avalanches have long posed a threat to the local populations of the Himalayan and Trans-Himalayan mountains. 
10. Land use intensification due to population growth, new transportation routes, defence related activities and tourism are continuously raising this level of risk.
11. The risks due to avalanche can be reduced if appropriate structural controls are employed. 
12. Methods of avalanche control include structural terrain modification to deflect the sliding snow away from the fixed facilities to be protected, or to actually prevent the avalanche release, and the planned release of small snow slides with explosives before snow accumulation increases their destructive potential to unmanageable proportions. 
13. Engineering structures for the control of snow avalanches are of the following four types:
1. Supporting structures to prevent avalanches from initiating, or to retard movement before it gains momentum. For example:
1. Massive earth or stone walls and terraces
2. Rigid structures 
3. Flexible supporting structures called ‘snow nets’ 
2. Deflecting and retarding structures in the run-out zone to keep the moving snow of an avalanche away from structures in critical locations
3. Retarding structures usually stop all but large, dry snow avalanches
4. Direct protection structures like avalanche sheds or shelters are roofs over roads or  railroads that allow avalanches to cross the road/railroad without interrupting or threatening the traffic.
14. In India, the responsibility of dealing with the different aspects of avalanches rests with the Border Roads Organisation (BRO)

Drought

 Drought

• Drought is a prolonged dry period in the natural climate cycle that can occur anywhere in the world. 
• It is a slow-onset disaster characterized by the lack of precipitation, resulting in a water shortage. 
• Drought can have a serious impact on health, agriculture, economies, energy and the environment.
• Rising temperatures caused by climate change are making already dry regions drier and wet regions wetter. 
• In dry regions, this means that when temperatures rise, water evaporates more quickly, and thus increases the risk of drought or prolongs periods of drought.
• Drought is termed as any lack of water to satisfy the normal needs of agriculture, livestock, industry or human population. It is shaded in red/yellow on the given maps.
• The main types of drought are as follows:
1. Meteorological Drought: Reduction in rainfall for a specific period below a specific amount
2. Hydrological Drought: Drying up of water sources – both surface and groundwater (together or individually)
3. Soil Moisture Drought: Unavailability of adequate moisture to support the standing crop.
4. Ecological Drought: Productivity of a natural ecosystem falls significantly as a consequence of distress induced environmental damage.
• In India, since 60% of the agriculture is still rainfed, meteorological drought is an important cause of drought conditions. Thus, any deficit in monsoon rains is felt to a large extent especially in areas that have large rain variability – leeward side of Western Ghats (Marathwada and Vidarbha) and North-west extremities of the country.

Heat wave and cold wave

Heat wave

Heat wave is a prolonged period of extremely high temperatures that typically lasts for several days to weeks and can have significant impacts on human health, the environment, and the economy. Heat waves are often associated with stagnant air masses and high humidity, which can exacerbate the impacts of high temperatures.

Effects of Heat Wave:

Heat-related illnesses: Heat waves can lead to a range of heat-related illnesses, including heat exhaustion, heatstroke, and dehydration.

Poor air quality: High temperatures can increase the formation of ground-level ozone and other air pollutants, which can have significant impacts on respiratory health.

Crop failure and water shortages: Heat waves can lead to crop failure, water shortages, and other impacts on agricultural productivity and food security.

Power outages and infrastructure failure: High demand for electricity during heat waves can lead to power outages and infrastructure failure.

Control Measures:

Affected individuals should drink plenty of water and avoid alcohol and caffeine, which can dehydrate the body.

Affected individuals should spend time in air-conditioned buildings or use fans and other cooling devices to lower body temperature.

Populations should avoid outdoor activities during peak hours and limit outdoor activities during the hottest parts of the day and schedule activities for early morning or evening when temperatures are cooler.

It is recommended to wear lightweight, light-colored, loose-fitting clothing to stay cool and protect skin from the sun.

Regular and frequent monitoring of the elderly, sick, or other vulnerable populations who may be at greater risk during heat waves.

It is generally recommended to reduce energy use during peak hours by turning off non-essential appliances and using energy-efficient cooling devices.

It is advisable to invest in infrastructure and community resilience to prevent and mitigate the impacts of heat waves, such as green roofs, heat-resistant building materials, and early warning systems.

Effective management of heat waves requires a coordinated response across multiple sectors, including public health, emergency management, and infrastructure planning and management.

Cold wave

A cold wave is a prolonged period of extremely cold temperatures, often accompanied by strong winds and/or precipitation, that can have significant impacts on human health, the environment, and the economy. Cold waves can be caused by a variety of factors, including changes in weather patterns and atmospheric conditions.

Effects of Cold Wave:

Hypothermia and frostbite: Cold waves can lead to hypothermia and frostbite, which can cause permanent damage to the body and even be life-threatening.

Poor air quality: Cold waves can lead to the formation of air pollutants, including particulate matter and carbon monoxide, which can have significant impacts on respiratory health.

Infrastructure failure: Cold waves can cause infrastructure failure, including power outages and water supply disruptions.

Reduced agricultural productivity: Cold waves can reduce agricultural productivity and increase the risk of crop failure, leading to food shortages and increased food prices.

Control Measures:

Dress warmly: Wear warm, layered clothing to protect the body from the cold and wind.

Stay indoors: Limit outdoor activities during the coldest parts of the day and spend time indoors in heated buildings.

Keep home warm: Maintain indoor temperatures at or above 18°C (65°F) and ensure that homes are properly insulated to conserve heat.

Use safe heating devices: Use safe heating devices, such as electric heaters or wood stoves, and follow manufacturer's instructions to prevent carbon monoxide poisoning and other hazards.

Check on vulnerable populations: Check on elderly, sick, or other vulnerable populations who may be at greater risk during cold waves.

Reduce energy use: Reduce energy use by turning off non-essential appliances and using energy-efficient heating devices.

Build resilience: Invest in infrastructure and community resilience to prevent and mitigate the impacts of cold waves, such as emergency heating centers and early warning systems.

Effective management of cold waves requires a coordinated response across multiple sectors, including public health, emergency management, and infrastructure planning and management.

Biological disasters

Biological disasters

Biological disasters refer to catastrophic events caused by infectious diseases or biological agents that pose a significant threat to human health and the environment. Some examples of biological disasters include:

COVID-19 pandemic: A global pandemic caused by the SARS-CoV-2 virus, which emerged in 2019 and has caused millions of deaths and significant economic and social disruption.

Ebola outbreak: An outbreak of Ebola virus in West Africa in 2014-2016 that caused over 11,000 deaths and had significant impacts on public health and the economy.

Anthrax attacks: In 2001, a series of attacks using anthrax spores sent through the mail in the United States resulted in several deaths and widespread fear.

Bovine spongiform encephalopathy (BSE) or mad cow disease: A prion disease that affects cows and can be transmitted to humans, causing variant Creutzfeldt-Jakob disease, which has significant impacts on human health.

Avian influenza (bird flu): An infectious disease caused by the H5N1 virus that can infect birds and humans, with significant impacts on public health and the economy.

Foot-and-mouth disease (FMD): A highly contagious viral disease that affects livestock and can cause significant economic impacts in the agricultural sector.

Malaria outbreak: A mosquito-borne infectious disease that affects millions of people worldwide, particularly in developing countries with limited access to healthcare.

Biological disasters can have significant impacts on public health, the economy, and the environment, and can be challenging to prevent and control. Effective prevention and management of biological disasters require early detection and rapid response, effective risk communication, investment in research and development, and building resilience in health systems and communities.

Technological disasters

Technological disasters

Technological disasters refer to catastrophic events that are caused by failures or accidents in technology-related systems, such as industrial facilities, transportation networks, energy infrastructure, and communication systems. Some examples of technological disasters include:

Chernobyl nuclear disaster: In 1986, a reactor at the Chernobyl nuclear power plant in Ukraine exploded, releasing radioactive material into the environment and causing significant health and environmental impacts.

Deepwater Horizon oil spill: In 2010, an explosion on the Deepwater Horizon oil rig in the Gulf of Mexico caused a massive oil spill that lasted for months, damaging marine ecosystems and coastal communities.

Fukushima nuclear disaster: In 2011, an earthquake and tsunami in Japan caused a meltdown at the Fukushima Daiichi nuclear power plant, resulting in the release of radioactive materials and long-term environmental and health impacts.

Bhopal gas tragedy: In 1984, a gas leak at a pesticide plant in Bhopal, India, released toxic gas into the surrounding community, resulting in thousands of deaths and long-term health impacts.

Space shuttle disasters: In 1986 and 2003, two separate disasters involving the space shuttle program resulted in the deaths of all crew members and significant impacts on the space program.

Flint water crisis: In 2014, the city of Flint, Michigan, switched its water supply to a contaminated source, resulting in a public health crisis and long-term impacts on the community.

The Three Mile Island nuclear accident: In 1979, a partial meltdown of a nuclear reactor at the Three Mile Island power plant in Pennsylvania resulted in a significant release of radioactive material and long-term environmental and health impacts.

Technological disasters can have significant impacts on human health, the environment, and the economy, and can take years or decades to recover from. Preventing technological disasters requires effective risk assessment and management, regulation and oversight, and investment in technology and infrastructure that is resilient and designed to prevent failures and accidents.

Global disaster trends

Global disaster trends

Changing risks are becoming increasingly important due to various factors, such as rapid urbanization, globalization, climate change, and technological advancements. Some examples of emerging risks of disasters include:

1. Cybersecurity threats: As more critical infrastructure and services become digitized, there is an increasing risk of cyber-attacks that can disrupt essential services and cause significant economic and social damage.

2. Pandemics: The emergence and rapid spread of infectious diseases, such as the COVID-19 pandemic, can cause widespread illness, death, and economic disruption.

3. Urbanization: As more people move to urban areas, there is an increased risk of disasters related to population density, such as heatwaves, urban flooding, and building collapses.

4. Climate change: Rising global temperatures, sea level rise, and extreme weather events are increasing the frequency and intensity of disasters, such as hurricanes, wildfires, and droughts.

5. Social and political instability: Political conflicts, social unrest, and economic crises can exacerbate the impacts of disasters, particularly in vulnerable and marginalized communities.

6. Technological hazards: The increasing use of hazardous materials and technologies, such as nuclear power and genetically modified organisms, can pose significant risks to human health and the environment in the event of a disaster.

7. Financial risks: The increasing interconnectedness of global financial systems can amplify the economic impacts of disasters and create systemic risks to the global economy.

Addressing emerging risks of disasters requires a proactive and multidisciplinary approach that involves stakeholders from various sectors and levels of society. This includes developing risk assessments and early warning systems, investing in disaster preparedness and response, promoting sustainable development and resilience-building measures, and addressing the root causes of vulnerability and risk.

Emerging risks of disasters

 Emerging risks of disasters

Emerging risks of disasters refer to new or changing risks that are becoming increasingly important due to various factors, such as rapid urbanization, globalization, climate change, and technological advancements. Some examples of emerging risks of disasters include:

Cybersecurity threats: As more critical infrastructure and services become digitized, there is an increasing risk of cyber-attacks that can disrupt essential services and cause significant economic and social damage.

Pandemics: The emergence and rapid spread of infectious diseases, such as the COVID-19 pandemic, can cause widespread illness, death, and economic disruption.

Urbanization: As more people move to urban areas, there is an increased risk of disasters related to population density, such as heatwaves, urban flooding, and building collapses.

Climate change: Rising global temperatures, sea level rise, and extreme weather events are increasing the frequency and intensity of disasters, such as hurricanes, wildfires, and droughts.

Social and political instability: Political conflicts, social unrest, and economic crises can exacerbate the impacts of disasters, particularly in vulnerable and marginalized communities.

Technological hazards: The increasing use of hazardous materials and technologies, such as nuclear power and genetically modified organisms, can pose significant risks to human health and the environment in the event of a disaster.

Financial risks: The increasing interconnectedness of global financial systems can amplify the economic impacts of disasters and create systemic risks to the global economy.

Addressing emerging risks of disasters requires a proactive and multidisciplinary approach that involves stakeholders from various sectors and levels of society. This includes developing risk assessments and early warning systems, investing in disaster preparedness and response, promoting sustainable development and resilience-building measures, and addressing the root causes of vulnerability and risk.

Climate change and urban disasters

CLIMATE CHANGE

Climate change refers to a long-term shift in the Earth's climate system, including changes in temperature, precipitation patterns, and extreme weather events, that are primarily driven by human activity, particularly the emission of greenhouse gases into the atmosphere.

The Earth's climate has always undergone natural variations over time, but the current changes are occurring at an unprecedented rate and are largely attributed to the increase in atmospheric concentrations of carbon dioxide and other greenhouse gases due to the burning of fossil fuels, deforestation, and other human activities.

The effects of climate change are far-reaching and include rising sea levels, more frequent and severe heat waves, droughts, floods, and storms, as well as changes in ecosystem dynamics and the distribution of plant and animal species. These impacts have significant consequences for human societies and economies, affecting food and water security, human health, infrastructure, and energy systems, among other areas.

Mitigating and adapting to the impacts of climate change require a collective effort by individuals, communities, governments, and businesses, including reducing greenhouse gas emissions, transitioning to cleaner and more sustainable energy systems, protecting and restoring ecosystems, and developing adaptive strategies to reduce vulnerability to climate impacts.

URBAN DISASTER

An urban disaster is an unexpected event or series of events that disrupts the normal functioning of a city or urban area, resulting in significant human, material, economic, or environmental losses. Urban disasters can be caused by a variety of factors, including natural hazards such as earthquakes, floods, hurricanes, and wildfires, as well as human-made hazards such as terrorist attacks, industrial accidents, and civil unrest.

Urban disasters can have a significant impact on the people living in affected areas, as well as on the infrastructure, institutions, and systems that support the functioning of cities. In addition to causing physical damage and loss of life, urban disasters can also result in social and economic disruption, displacement of populations, and long-term effects on public health, the environment, and the economy.

Effective disaster management and preparedness strategies can help mitigate the impact of urban disasters by improving risk reduction, emergency response, and post-disaster recovery and reconstruction efforts. These strategies involve a wide range of stakeholders, including government agencies, non-governmental organizations, communities, and individuals, and require a multidisciplinary approach that integrates social, economic, environmental, and technological factors.