What is hazard?
Hazard is a dangerous phenomenon, substance, human activity or condition that may cause loss of life, injury or other health impacts, property damage, loss of livelihoods and services, social and economic disruption, or environmental damage.
How would you define vulnerability?
Vulnerability is the characteristics and circumstances of a community, system or asset that make it susceptible to the damaging effects of a hazard. There are many aspects of vulnerability, arising from various physical, social, economic, and environmental factors. Examples may include poor design and construction of buildings, inadequate protection of assets, lack of public information and awareness, limited official recognition of risks and preparedness measures, and disregard for wise environmental management. Vulnerability varies significantly within a community and over time. This definition identifies vulnerability as a characteristic of the element of interest (community, system or asset) which is independent of its exposure. However, in common use the word is often used more broadly to include the element's exposure.
What is Risk?
Risk is the combination of the probability of an event and its negative consequences. The word "risk" has two distinctive connotations: in popular usage the emphasis is usually placed on the concept of chance or possibility, such as in "the risk of an accident"; whereas in technical settings the emphasis is usually placed on the consequences, in terms of "potential losses" for some particular cause, place and period. It can be noted that people do not necessarily share the same perceptions of the significance and underlying causes of different risks.
What is disaster risk?
Disaster risk is the potential disaster losses, in lives, health status, livelihoods, assets and services, which could occur to a particular community or a society over some specified future time period. The definition of disaster risk reflects the concept of disasters as the outcome of continuously present conditions of risk. Disaster risk comprises different types of potential losses which are often difficult to quantify. Nevertheless, with knowledge of the prevailing hazards and the patterns of population and socio-economic development, disaster risks can be assessed and mapped, in broad terms at least.
What is disaster
According to Section 2 (d) of the Disaster Management Act, 2005 "disaster means a catastrophe, mishap, calamity or grave occurrence in any area, arising from natural or man-made causes, or by accident or negligence which results in substantial loss of life or human suffering or damage to, and destruction of, property, or damage to, or degradation of, environment, and is of such a nature or magnitude as to be beyond the coping capacity of the community of the affected area."
Disasters are often described as a result of the combination of: the exposure to a hazard; the conditions of vulnerability that are present; and insufficient capacity or measures to reduce or cope with the potential negative consequences. Disaster impacts may include loss of life, injury, disease and other negative effects on human physical, mental and social well-being, together with damage to property, destruction of assets, loss of services, social and economic disruption and environmental degradation.
What is disaster prevention?
Disaster prevention is the outright avoidance of adverse impacts of hazards and related disasters prevention (i.e. disaster prevention) expresses the concept and intention to completely avoid potential adverse impacts through action taken in advance. Examples include dams or embankments that eliminate flood risks, land-use regulations that do not permit any settlement in high risk zones, and seismic engineering designs that ensure the survival and function of a critical building in any likely earthquake. Very often the complete avoidance of losses is not feasible and the task transforms to that of mitigation. Partly for this reason, the terms prevention and mitigation are sometimes used interchangeably in casual use.
What does disaster mitigation mean?
Mitigation means the lessening or limitation of the adverse impacts of hazards and related disasters. The adverse impacts of hazards often cannot be prevented fully, but their scale or severity can be substantially lessened by various strategies and actions. Mitigation measures encompass engineering techniques and hazard-resistant construction as well as improved environmental policies and public awareness. It should be noted that in climate change policy, "mitigation" is defined differently, being the term used for the reduction of greenhouse gas emissions that are the source of climate change.
What is disaster preparedness?
Preparedness constitutes the knowledge and capacities developed by governments, professional response and recovery organizations, communities and individuals to effectively anticipate, respond to, and recover from, the impacts of likely, imminent or current hazard events or conditions. Preparedness action is carried out within the context of disaster risk management and aims to build the capacities needed to efficiently manage all types of emergencies and achieve orderly transitions from response through to sustained recovery. Preparedness is based on a sound analysis of disaster risks and good linkages with early warning systems, and includes such activities as contingency planning, stockpiling of equipment and supplies, the development of arrangements for coordination, evacuation and public information, and associated training and field exercises. These must be supported by formal institutional, legal and budgetary capacities. The related term "readiness" describes the ability to quickly and appropriately respond when required.
What is resilience?
Resilience is the ability of a system, community or society exposed to hazards to resist, absorb, accommodate to and recover from the effects of a hazard in a timely and efficient manner, including through the preservation and restoration of its essential basic structures and functions. Resilience means the ability to "resile from" or "spring back from" a shock. The resilience of a community in respect to potential hazard events is determined by the degree to which the community has the necessary resources and is capable of organizing itself both prior to and during times of need.
What is Disaster Management?
Section 2 (e) of the Disaster Management Act 2005, describes "disaster management" means a continuous and integrated process of planning, organising, coordinating and implementing measures which are necessary or expedient for:
-
Prevention of danger or threat of
any disaster.
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mitigation or reduction of risk
of any disaster or its severity or consequences.
-
capacity-building.
-
preparedness to deal with any
disaster.
-
prompt response to any
threatening disaster situation or disaster.
-
assessing the severity or
magnitude of effects of any disaster.
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evacuation, rescue and relief.
-
rehabilitation and
reconstruction.
What emergency supplies do I need to face a disaster event?
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Adequate supplies of medications
that you or family members are taking.
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Crescent and pipe wrenches to
turn off gas and water supplies.
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First-aid kit and handbook.
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Flashlights with extra bulbs and
batteries.
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Portable radio with extra
batteries.
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Water for each family member for
at least 3 days (allow at least 1 gallon per
person per day) and purification tablets or
chlorine bleach to purify drinking water from
other sources.
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Canned and package foods, enough
for several days and mechanical can opener.
Extra food for pets, if necessary.
-
Camp stove or barbecue to cook on
outdoors (store fuel out of the reach of
children).
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Waterproof, heavy-duty plastic
bags for waste disposal.
Whom to contact for emergency
response?
Please dial toll free 108 number for medical,
fire and police emergency. No local code is
required to do so. You can also dial the
district disaster control room i.e. toll free
1077 number by adding the district code.
Alternative 112 number for police and 101 for
fire can be dialed.
What is the provision of
disaster relief?
The victims of disaster or their dependents
as may be the case are provided relief as per
the UP Emergency Relief Manual and guidelines
issued by the Government of India, Ministry of
Home Affairs. The Sub-Divisional Magistrate of
the area is competent to sanction the cases
prepared under the manual. He is also competent
to provide immediate relief and rescue
assistance. For details about the type and
quantum of relief please read the MHA guidelines
which are appended below.
Whom to contact for emergency response?
Please dial toll free 108 number for medical, fire and police emergency. No local code is required to do so. You can also dial the district disaster control room i.e. toll free 1077 number by adding the district code. Alternative 100 number for police and 101 for fire can be dialed.
What is the provision of disaster relief?
The victims of disaster or their dependents as may be the case are provided relief as per the UP Emergency Relief Manual and guidelines issued by the Government of India, Ministry of Home Affairs. The Sub-Divisional Magistrate of the area is competent to sanction the cases prepared under the manual. He is also competent to provide immediate relief and rescue assistance. For details about the type and quantum of relief please read the MHA guidelines which are appended below.
What is a thunderstorm?
As per World Meteorological Organisation (WMO) “A thunderstorm is one or more sudden electrical discharges, manifested by a flash of light (lightning) in the sky and a sharp or rumbling sound (thunder).”
Thunderstorm is generally associated with severe weather.
What is the audible range of thunderstorm?
The audibility of thunderstorm is normally about 20km i.e. you can hear a thunder if it occurs with a distance of upto 20km around you. Sometimes, it can be heard 40 km away.
What is a thunder cloud?
The cloud which produces thunder and lightning is called a thunder cloud. Scientifically, it is known as cumulonimbus (Cb) cloud. It is a type of convective cloud which can extend up to a height of 10-15 km.
Is lightning associated with every thunderstorm?
Yes, as thunder is just a loud sound produced by the process of electric discharge between the different charges in cloud or between a cloud and ground which also produces sharp flashes of light. The common example of this can be seen during a short circuit in household electric wiring.
Why is the lightning produced?
The thunder cloud contains ice particles and small hail particles called ‘Graupel’. When they collide, charge transfer takes place between them. The +ve and –ve charges gets accumulated at different parts of the cloud. The earth’s surface also contains +ve and –ve charges. When these charges exceed a certain limit they break the insulating barrier of air and get neutralised through discharging process which produces a sharp flash of light.
How dangerous is lightning?
Lightning is highly dangerous for us as it can have 100 million to 1 billion volts, and contains billions of watts of electricity and huge quantity of heat (more than 35,000 degrees Fahrenheit) which can melt metal and turn sand into glass. So, it is highly dangerous and fatal for us.
Lightning kills hundreds of people around the world every year. Even in India, according to National Crime Bureau of India report it kills more than 2500 persons every year.
What are the types of lightning?
Based on whether the discharge process is between clouds or cloud and earth, the lightning is of three types:
(i) Intra cloud (IC) Lightning: When the discharge takes place between opposite charges accumulated at different parts of the same cloud.
(ii) Cloud to cloud (CC) Lightning: When the discharge takes place between opposite charges accumulated in different clouds.
(iii) Cloud to ground (CG) Lightning: When the discharge takes place between opposite charges accumulated in a cloud and earth’s surface.
The third one, that is cloud to ground lightning is dangerous for us
What are negative and positive cloud to ground (CG) lightning?
When discharge occurs between negative charges in cloud and positive charges at earth’s surface it is termed as negative cloud to ground lightning. On the other hand if discharge takes place between positive charges in cloud and negative charges at earth’s surface it is termed as positive cloud to ground lightning.
How do I recognize that a thunderstorm is approaching my location?
There are certain changes associated with the approaching thunderstorm
1. Rush of cool air towards you.
2. Appearance of huge greyish-black tall cylindrical cauliflower like clouds in the sky.
3. Thunder sound produced by a cloud and lightning in the sky.
4. Hair standing up on the back of your neck could indicate that lightning is imminent very close to you.
When do I need to take action to protect myself?
Strictly follow the ‘30-30 Rule’ of WMO which offers best Lightning Safety Guidance for the general public. When you see lightning, count the time until you hear thunder. If that is 30 seconds or less, the thunderstorm is close enough to be dangerous – seek shelter (if you can’t see the lightning, just hearing the thunder is a good back-up rule). Wait 30 minutes or more after the lightning flash before leaving shelter.
Can I calculate approximate distance of origin of lightning and thunder from myself?
Yes, it is very easy. Start counting the seconds when you see the lightning flash till you hear the thunder. Simply divide these no. of seconds by 3, you will get the distance of origin of lightning & thunder from you in kms.
Why do I need to protect myself when a thundercloud is far away from my location?
Lightning strikes have been recorded 10-12 km away from a thundercloud. Hence a thundercloud need not be overhead to be harmful.
Where is lightning more likely to strike?
The lightning is more likely to strike raised places over earth’s surface like tall buildings or structures, trees, metallic objects, electric wires, standing animals and humans, water bodies etc. as these objects provide easy conduction path for discharging process and hence lightning strike.
What is a “bolt from the blue”?
It means lightning that strikes the ground from blue sky i.e. without any cloud. We know that a lightning is originated in a thunder cloud, but sometimes, it happens that the lightning travels horizontally away from the cloud up to a few kilometres and then strike the ground. It appears that lightning has originated from blue sky and hence got it name.
How does a cloud form?
Due to the heating of earth’s surface particularly in summer season, the air near the ground also gets heated and becomes lighter which in turn starts rising. As this air rises, it cools and the moisture contained in the air starts condensing into water droplets, which leads to cloud formation. So, cloud is composed of condensed water vapours.
Is thunder cloud dangerous?
Thunder cloud is the most dangerous cloud as this is the only cloud that gives thunder, lightning, strong winds, flash floods etc. which are highly destructive in nature and are associated with huge loss of life and property.
Are all thunderstorms equally dangerous?
No, the severity of the thunderstorms depends on many factors like atmospheric instability, moisture availability, local orography, presence of large scale weather systems, prevailing winds at different levels etc. So, when a thunderstorm encounters the suitable environment with all factors supporting its growth, it becomes dangerous.
Which season is more favourable for severe thunderstorms?
In India, the March to August period is most favourable for severe thunderstorms. Hail is more frequent during February to May period, squall and gusty winds during April to July, flash floods during April to September and lightning during April to September period. However, please check from the local Meteorological Centre for the most prevalent period for your region.
In addition to actually seeing them, what instruments detect thunderstorms?
In addition to visual detection, thunderstorms can be detected by
(a) weather Radar,
(b) Satellites and
(c) Lightning sensors.
What is the height of the thunder cloud?
The base of the thunder cloud is about 1km or less, but top is very high- about 10 to 15 km or higher.
Do thunderclouds affect aircraft movement?
Yes, on account of high wind turbulence associated with thunderstorms, aircrafts are not allowed to land or take off during thunderstorms over an airport. While in flight, aircraft avoid thunderstorm clouds to prevent inflight turbulence inside the aircraft and icing on the body of the aircraft.
What are various stages of thunderstorm life cycle.
The life cycle of thunderstorm cloud has three stages:
1. Growing Stage,
2. Mature Stage
3. Dissipating Stage.
Which stage of the thunder cloud is dangerous?
The mature stage of the thunder cloud is most dangerous as only this stage of thunder cloud is associated with all types of severe weather.
What are various types of thunderstorms?
Various types of thunderstorms are:
Isolated or single-cell thunderstorms: These are small, brief, weak storms and die within an hour or so.
Multi-cell thunderstorm: It contains number of cells having different stages of life cycle.
Supercell thunderstorm: It is a long-lived and highly organized storm with a tilted or rotating updraft. The rotating updraft is called a mesocyclone and is well captured by Doppler radar. It lasts
Squall-line thunderstorm: A line of thunderstorms usually hundreds of kilometre in length and a few km in width and propagating perpendicular to its axis.
What is the life time of the thunderstorm?
The life time of an isolated thunderstorm is about half an hour to one hour or slightly more. On the other hand the life time of multi-cell thunderstorm or super cell or a squall line may be upto several hours (8-10 hours on an average).
What is the spatial extent of thunderstorm?
A thunderstorm is a weather system having spatial scale of a few kilometres (isolated thunderstorm) to a few hundred kilometres (multi-cell, super-cell and squall line thunderstorms).
What is a hailstorm?
Sometimes we observe solid ice balls of size ranging from that of a pea to cricket ball size falling from clouds to ground. These ice balls are termed as hailstones or simply hail and the phenomenon is called hailstorm. They sometimes reach the ground at speeds of up to 150 km/h.
How does hail form?
In thunderclouds, there is ice formation at heights beyond freezing level. When the thundercloud is especially severe, these ice particles grow while they collide with each other and grow to larger size. When the resulting ice balls gain weight they come down due to gravity and falls on ground and are known as hail.
Do all thunderclouds contain hail particles?
All thunder clouds have height well beyond freezing level, and contain small ice particles. But generally these particles melt and fall as rain on the ground due to warm air below the cloud base.
Why are strong winds associated with a thunder cloud?
In a thunder cloud, air from the upper parts of the cloud which is colder and heavier, rush downwards with a great force along with hydrometeors (water in liquid or solid form). These sudden puffs of strong winds cause gusty winds at the surface.
What is a squall?
Squall is a special case of gusty winds in which there is a sudden sharp increase of winds by at least 16 kts (32 kmph) and reaching to 22 kts (45 kmph) and lasting for at least one minute.
What is a tornado?
A tornado is a narrow and violently rotating column of air that extends from the base of a thunder cloud to the ground resembling the shape of a funnel. Therefore, it is also called a funnel cloud. It leaves a trail of destruction in the form of debris along its path and is very violent.
What is a waterspout?
Waterspouts are tornadoes that occur on water bodies. They are generally less severe than land tornadoes.
Can frogs or small fishes or water creatures come down with rain?
Yes, in association with waterspouts, sometimes along with water small water creatures are lifted up to the sky by the strong updrafts of convection. These creatures fall down elsewhere along with rain.
Do tornadoes occur in India?
Tornadoes are sometimes observed over India in the summer months of March to May. The tornado prone areas in India include West Bengal, Assam & adjoining states and north India plains. Over Asia, violent tornadoes are common over Bangladesh. A recent moderate intensity tornado hit the Bakainwala village in the Fazilka district of Punjab on 24th March, 2023, causing extensive damage to over 50 houses and injuring over half a dozen people(source: media).
In what kind of clouds do tornadoes occur?
Tornadoes occur in severe thunderstorm systems such as Bow echo squall lines and supercells. The tornado can also occur in the forward sector of a cyclone approaching land. Recently in 2021 there was a tornado in association with Cyclone YAAS, which crossed Odisha coast on 26th May 2021.
Why house roofs are blown during severe wind storm like tornado?
High-speed winds due to a tornado, reduce the air pressure outside closed spaces like a house whose pressure remains unchanged due to being closed. Due to this pressure gradient, High pressure inside pushes the roof upwards and windows outwards due to Pressure Gradient Force which is directed from High Pressure to Low Pressure. That's why roofs of the kutcha houses and huts are blown off during high-speed winds or tornado.
What is a dust storm?
When strong downward winds from the thunder cloud hit the ground with a great force they raise the loose soil/dust from the ground which reduces the horizontal visibility to less than 1km. This is known as convective duststorm. It is generally called ‘Andhi’ in North India as it makes a person momentarily visually impaired (Andha). Duststorm mainly occurs over north Indian states of Rajasthan, Haryana, Punjab, Uttar Pradesh. It does not last for a long time and ceases if there is sufficient rain wetting the ground.
Is there any other reason for duststorm
Yes, duststorm may also be caused by the steep pressure gradient i.e. change in pressure with distance during the summer months. During the summer months, high surface temperatures produces low pressure over Rajasthan with a steep pressure gradient all around. To fill this low pressure, air from all directions rushes towards this low pressure area raising the loose dust from the surface to great heights resulting in duststorms. This raised dust remains suspended in air for many days.
Is there any standard scale to estimate wind speeds based on associated effects?
Yes, one of the first scales to estimate wind speeds based on the effects was created by Britain's Admiral Sir Francis Beaufort (1774-1857). He developed the scale in 1805 to help sailors estimate the winds via visual observations. The scale starts with 0 (0 Kts) and goes to a force of 12(67-71 Kts). Beaufort scale is still used today to estimate wind strengths. Another scale which starts from last level of Beaufort scale, and estimates property damage associated with strong cyclonic storms is Saffir-Simpson Hurricane Wind Scale with 1 to 5 rating based on a hurricane's (very severe cyclonic storm in north Indian Ocean) sustained wind speed. The Fujita scale measures the strength of a tornado based on wind speed.
What are the damages expected from strong winds associated with thunderstorms?
The table below gives the different levels of strong winds and associated impact on various sectors along with the suggested actions.
Category/Wind Speed |
Structures |
Communication & Power |
Agriculture |
Suggested Actions |
Light Thunderstorm < 41 kmph (21 knots) |
|
|
|
|
Moderate Thunderstorms 41–61 kmph(22-33 knots) |
Minor damage to loose/unsecured structures |
|
Minor damage to Banana trees. Damage to ripe paddy crops |
People are advised to keep a watch on the weather for worsening conditions and be ready to move to safer places accordingly. |
Severe Thunderstorms 62-87 kmph(34-47 knots) |
Damage to thatched huts. |
Minor damage to power and communication. |
Some damage to paddy crops, banana, papaya trees and orchards and Standing crops. |
People are advised to take shelter in pukka structures and avoid taking shelter under trees. Farming operations to be temporarily suspended during |
Very Severe Thunderstorms Greater than 87 kmph {(47Kt) in gusts/squall} |
Major damage to thatched houses/huts. Roof tops may blow off. Unattached metal sheets may fly. |
Minor damage to power and communication lines. |
Breaking of tree branches, uprooting of large avenue trees. Moderate damage to banana and papaya trees. Large dead limbs blown from trees.Damage to Standing crops. |
People are advised to stay away from weak walls and structures and take shelter in pukka structures. People in affected areas to remain indoors and avoid water bodies and flying projectiles. Farming operations to be temporarily suspended during occurrence of event. |
Thunderstorm associated with Hailstorm |
Major damage to Kutcha structures and tin and asbestos roofed houses, cars |
|
The fruit, vegetable and field crops at maturity stages are more prone to damage. Damage to Standing crops. |
People are advised to stay away from weak walls and structures and take shelter in pukka structures. People in affected areas to remainindoors. |
Can we avoid lightning strike to our house or any other premises.
Yes, by installing lightning arrester. These are special instruments installed over a building which save the building from lightning strike along a particular area around it.
How lightning arrester works?
The lightning arrester neutralizes the charge accumulated over a cloud by providing it a conduction path. The charge accumulated in a cloud passes to deep in the earth through the conducting mechanism provided by the lightning arrester.
Can lightning be detected using some instrument?
Yes, the lightning can be detected by a special kind of instrument called lightning sensor or lightening detector.
How can I save myself from lightning ?
‘When thunder roars’, go indoors means go to a safe shelter immediately to avoid metal structures and constructions with metal sheeting. Safe shelters include pukka home, pukka building, or hard top vehicles with the windows rolled up.
What should I do if struck outside in open?
Do the following:
(i) Suspend all agricultural activities, till weather clears.
(ii) Immediately get off elevated areas such as hills, mountain ridges, or peaks.
(iii) Keep away from all utility lines and objects that conduct electricity (phone, power, metal fences, wind mills, etc.)
(iv) Immediately get out of the water bodies like ponds, water filled or wet fields.
(v) If no shelter is available, immediately get into the lightning crouch position.
What is the lightning crouch position?
Settle down in a ball-like position with your head tucked and hands over your ears
so that you are down low with minimal contact with the ground.
This is shown below:
Can I take shelter under the tree during thunder & lightning?
A big No. Never, take shelter under a tree especially under an isolated tree, as trees
conduct electricity and more prone to lightning strike. This is the most common region of
lightning related deaths. Instead if you don’t found any shelter, immediately get into
lightning crouch position as described above.
What precaution should I take at home during such weather?
Get immediately inside the house. Unplug any electronic equipment when you sense such weather around you. Stay indoors until the weather clears
What should I do if travelling in a vehicle?
If in open vehicles like motorcycles, golf carts, bicycles, farm vehicles(tractors etc.), immediately get out of them as may attract lightning.
If in closed and hard top vehicles like car, bus etc. with the windows rolled up you seems to be safe.
Do rubber-soled shoes and car tyres offer protection from lightning.
No, Rubber-soled shoes and car tyres do not offer any protection from lightning as lightning intensity is extremely high, can be about 100 million to 1 billion volts. The thickness of rubber sole or car tyres are not enough to protect from such a high voltage.
What are colour coded warnings for thunderstorm nowcast?
Thunderstorm nowcast warnings are given different colours based on the severity of the thunderstorm as shown below:
It is based on the likelihood of occurrence and impact expected from the weather.
Can I get thunderstorm and lightning forecast for next 2-3 or more days?
Yes, you can visit to the website of meteorological centre of India Meteorological department
for your respective state for getting detailed potential area of occurrence of thunderstorm and
associated severe weather. The forecast accuracy gradually increases as we approach towards the
day and time of occurrence. Thus IMD issues updated forecast twice a day at district level for up
to five days and nowcast every three hours valid for the next three hours.