Disasters-Natural Calamities

WHAT IS DISASTER?➔ Disaster is a sudden, calamitous event bringing great damage,

loss, and destruction and devastation to life and property. ➔ The damage caused by disasters is immeasurable and varies

with the geographical location, climate and the type of the earth surface/degree of vulnerability.

➔ This influences the mental, socio-economic, political and cultural state of the affected area.

Two Types(depends upon their potential to cause damage)

1) Major disasters ¨ Hurricanes, ¨ Floods / Sea Surges / Tsunamis¨ Snow storms, ¨ Earthquakes, ¨ Landslides, 2) Minor disaster: Localized and intensity of damage is much lessEx., Landslides, fire accidents

EFFECTS OF MAJOR DISASTERSDisasters has significant impact on the numbers, health status and life style of populations. They cause ¨ Deaths¨ Severe injuries, requiring extensive treatments¨ Increased risk of communicable diseases¨ Damage to the health facilities¨ Damage to the water systems¨ Food shortage¨ Population movements¨ Social reactions¨ Climatic exposure¨ Food and nutrition¨ Mental health¨ Damage to health infrastructure

India's Natural Disasters PronenessOn the basis of geographic and climatic considerations, India can be divided into 5 Zones according to its disaster proneness to natural disasters;1. Northern mountain region including foot hills; this region is prone to strong Snow Storms leading to Land slides and strong Cold waves and also is Earthquake prone belt with violent subterranean Volcanic activity.2. Indo-gangetic plains; heavy rains during monsoon make these plains vulnerable to Floods.3. Deccan plateau; a Drought prone area.4. The western desert; a Drought prone area.5. Coastal areas; they are prone to Sea erosion, Cyclones and Tidal waves

Disaster ManagementOverall measures to minimize loss and and recover from hazard impact➔It is the It is a sequential and continuous process by which all individuals, groups and communities manage hazards in an effort to avoid or minimize the impact of disasters resulting from hazards. ➔Effective disaster management relies on thorough integration of emergency plans at all levels of government and non-government involvementDisaster Cycle Consists of two phases1, Risk Reduction Phase, before a Disaster2. Recovery Phase, after a Disaster

Disaster ManagementThe fundamental aspects of Disaster Management Program¨ Disaster Prevention¨ Disaster preparedness¨ Disaster response ¨ Disaster mitigation Risk Reduction¨Rehabilitation or recovery¨ Reconstruction

● Mitigation:Activity that reduces either the chance of a hazard taking place or a hazard turning into disaster. Mitigative measures can be structural or non-structural.

●Risk reduction: anticipatory measures and actions that seek to avoid future risks as a result of a disaster.

●Preparedness: Plans or preparations made to save lives or property, and help the response and rescue service operations. This phase covers implementation/operation, early warning systems and capacity building so the population will react appropriately when an early warning is issued.

●Response: includes actions taken to save lives and prevent property damage, and to preserve the environment during emergencies or disasters. The response phase is the implementation of action plans like emergency evacuation, quarantine, mass decontamination, etc.

●Recovery: includes actions that assist a community to return to a sense of normalcy after a disaster. Recovery efforts are primarily concerned with actions that involve rebuilding destroyed property, re-employment, and the repair of other essential infrastructure.●Compensation for loss of life and property .prise Grant mercy releif to all affected people-Releif for economic construction

Different Aspects of Disaster Management

POST DISASTER PREVENTIVE MEASURES

• Maintenance of law and order, prevention of trespassing, looting etc.

• Evacuation of people.

• Recovery of dead bodies and their disposal.

• Medical care for the injured.

• Supply of food and drinking water.

• Temporary shelters like tents, metal sheds etc.

• Repairing lines of communication and information.

• Restoring transport routes.

• Quick assessment of destruction and demarcation of destroyed areas, according to the grade of damage.

• Cordoning off severely damaged structures that are liable to collapse during aftershocks.

Indian Scenario:The National Policy on disaster managementInvolves (National Institute of Disaster Management NIDM)It aims at

● prevention, mitigation and preparedness in pre-disaster phase ●Creation of awareness for disaster reduction and for improving preparedness amongst the communities, using media, school education, and the network of the building centre.●Appropriate amendments in the legislative and regulatory instruments●assessment surveys and investigations of the nature and extent of damage in post disaster situations. ●To ensure use of disaster resistant construction techniques-Making mandatory, the use of disaster resistant codes and guidelines related to disaster resistant construction in the houses and buildings●To promote the study of natural disaster prevention, mitigation and preparedness as subjects in architecture and engineering curricula.●To create detailed database on hazard occurrences, damage caused to buildings and infrastructure .●To devise appropriate policy instrument and funding support for urgent disaster preparedness and prevention actions ●To include R&D work in disaster preparedness, mitigation and prevention as a thrust area ● ●

A flood is an overflow of an expanse of water that submerges land. Rivers and channels are framed or adjusted themselves to accommodate average water flows But heavy rain or sudden snow fall will result in heavy water flow -These natural channels unable to carry all the waterExcess water overflows stream banks and covers adjacent land is considered flood

FLOOD

Causes of Floods

➔River in spate➔Snow melt➔Storm surges➔Short intense storm causing flash floods➔Flooding in rivers in mainly caused by: ➔Inadequate capacity within the banks of the rivers to contain high flows.➔River bank erosion and silting of riverbeds.➔Landslides leading to obstruction of flow and change in the river course.➔Synchronization of flood in the main tributary rivers.➔Flow retardation due to tidal and backwater effects.➔Poor natural drainage.➔Cyclone and heavy rainfall.

Effects of Flood

•Physical damage- Can range from bridges, cars, buildings, sewer systems, roadways, canals and any other type of structure.

•Casualties- People and livestock die due to drowning. It can also lead to epidemics and diseases.

Secondary effects

•Water supplies- Contamination of water. Clean drinking water becomes scarce.

•Diseases- Unhygienic conditions. Spread of ··water-borne diseases

•Crops and food supplies- Shortage of food crops can be caused due to loss of entire harvest.

•Trees - Non-tolerant species can die from suffocation Tertiary/long-term effects

•Economic- Economic hardship, due to: temporary decline in tourism, rebuilding costs, food shortage leading to price increase etc.

Flood Disaster Management

➢Structural: construction of ➢Dams and Reservoirs➢Embankments, flood walls, sea wall➢Natural detention basin➢Channel improvement➢Drainage improvement➢Diversion of floodwaters.➢Pre- and post-monsoon checks must be made special repairs must be carried out prior to flood period➢The non-structural measures➢Flood plain management➢Flood proofing including disaster preparedness, and response planning and Flood forecasting and Warning➢Disaster Relief➢Flood fighting including Public Health Measures➢Setting up of flood forecasting and warning services is one of the most cost-effective non- structural measures available.

PPreparedness against Floods

➢"Pre Monsoon Inspection" of all railway tracks, canals and drains by respective departments, which could include silt and details clearance from seasonal rivulets.➢Regular clearance of the drains from silt and weeds to make the drainage system fully functional and restoration of natural drainage blocked by roads, railway tracks and canal.➢Regular maintenance of embankments of rivers canals, distributors etc. and regular check of the canals and siphons and clearing them from silt.➢Clearing of storm water and sewerage drains in towns before monsoon.➢Constitution of committees comprising of heads of all emergency services, medical, police, transportation and the district administration to ensure proper co- ordination during the crisis.➢

➢Flood warning Dissemination procedures

➢The Government agency : through print and electronic media as well as informing the authorities concerned.

➢The District administration : Their responsibility to reach the especially who have no access to mass media modes by beat of drums, sounding of sirens, village gongs, if any or by word of mouth.

➢Public involvement: Some local means needs to be evolved and be kept in place to ensure that people come to know of the impending calamity and to take suitable follow- up action to save their lives and property as also to help the neighborhood wherever they can.

Flood Response and Recovery

➢ Rendering relief like - evacuation, rescue,providing food, shelter (temporary), drinking water, medical care, and few pieces of clothing, utensils.

➢Deployment of boats at strategic points

➢Submission of daily reports and disseminate correct information through media to avoid rumors

➢Once the calamity is over, relief can help people restore their lives back to normal by helping them repair/ rebuild their houses, helping them in restarting their small businesses

➢Compensation for loss of life and property .prise

➢ Repairs and construction of infrastructural facilities

➢Rehabilitation of homeless

➢Commencement of agricultural activities-dsesiltation, resowing

➢Grant mercy releif to all affected people and releif for economic construction

EARTHQUAKES

An earthquake is a sudden motion or trembling of the ground produced by the abrupt displacement of rock masses along the faults

The sudden movement within the crust or mantle create concentric waves from the point.

The point where the earthquake's motion starts is called focus

The epicenter is the point on the earth's surface that is directly above the focus.

Earthquake Magnitude is a measure of the strength of an earthquake

Richter scale is commonly used today to describe anearthquake's magnitude.

Causes of earth quake Main Causes

●Tectonic activity: When tension is released from the

rocks in the earth,crust and upper mantle.

●Volcanic Action: magmatic outbursts from within the

interior of the earth

●Man made:Explosion of high power nuclear or atomic

bomb, Decrease in underground water level, Hydrostatic

pressure of man-made water bodies like reservoirs,

dams, and lakes which in turn causes the movement of

tectonic plates

Direct Hazards ¨ · Ground shaking¨ · Differential ground settlement¨ · Soil liquefaction¨ Immediate landslides or mud slides, ground lurching and avalanches¨ · Permanent ground displacement along faults¨ · Floods from tidal waves, Sea Surges & Tsunamis

Indirect Hazards ¨ · Dam failures;¨ · Pollution from damage to industrial plants;¨ · Delayed landslides. Most of the damage due to earthquakes is the result of strong ground shaking.

PRE-DISASTER PREVENTIVE (MITIGATIVE) MEASURES Structural● The actual impact of earthquake is greatly influenced by the building material and construction methods adopted. ●To overcome this problem, standards has been formulated in the field of design and construction of earthquake resistant structures.

·Constructing earthquake-resistant community buildings and buildings (used to gather large groups during or after an earthquake) like schools, dharamshalas, hospitals, prayer halls, etc., especially in seismic zones of moderate to higher intensities.

·Retrofitting of weak structures in highly seismic zones.● Incorporating earthquake resistant features in all buildings at

high-risk areas.

Non-structural

• Re-framing buildings' codes, guidelines, manuals and bye laws and their strict implementation. Tougher legislation for highly seismic areas.

· Evolving educational curricula in architecture and engineering institutions and technical training in polytechnics and schools to include disaster related topics

· Preparation of disaster related literature in local languages with dos and don'ts for construction.

· Getting communities involved in the process of disaster mitigation through education and awareness.

· Networking of local NGOs working in the area of disaster management

Earthquake preparedness: • Response doctrines for state and local government

··emergency services.

• Preparedness plans for individuals and businesses.

• Train communities in high-risk areas in post-disaster search, rescue and relief.

• Practice an extensive programme of mass drills in high-risk areas for earthquake damage reduction.

• Train local NGOs and strengthen their capacity and capabilities.

• Inculcate basic know-how amongst school kids on earthquake dos and donts along with safety drills.

• Train field personnel in the science and art of carrying out post disaster damage surveys, for (a) urgent relief purposes and (b) for repair, reconstruction and retrofitting purposes.

Earth quake response

Safety lies in evacuating people to safer pre-designated areas along with their precious belongings for the duration of the calamity.

Generally safe places (at higher elevations) are the pucca building i.e. school, Panchayat Ghar and other public and identified private buildings.

Emergency sanitation, alternative supplies of water, custody of valuables, care of animals etc.,

Provision of welfare facilities e.g.,information and guidance on essential matters, alternative of including food, clothing and shelter

Plans of rescue of causalities trapped under debris

Removal of debris

Disposal of dead and their identification

Restoration of communications

Mobilisation of transport

Earthquake RecoveryDuring emergencies, affected people need to be involved in the relief activities so as to create a feeling of self-reliance.Post-disaster work would involve:

• Detailed survey of buildings for assessment of damage and repair/ reconstruction and seismic strengthening or demolition.

• Selection of sites for new settlements, if required.

• Execution of the reconstruction programme.

• Review of the existing seismic zoning maps and risk maps.

• Review of seismic codes and norms of construction.

• Training of personnel, engineers, architects, builders and masons.

Camp-work and employment Outside releif

CYCLONE.➔Cyclones are huge revolving storms caused by winds blowing around central area of low atmospheric pressure.➔Cyclones are called hurricanes or typhoons and their winds blow in an anti-clockwise circle in the northern hemisphere➔In the southern hemishpere the tropical storms are known as cyclones whose winds blow in a clockwise direction. ➔Cyclones are classified on the basis of the average speed of the wind near the centre of the system as follows: ➔Wind Speed Classification➔¨ Up to 61 km/hr Tropical Depression➔¨ 61 km/hr - 115 km/hr Tropical Storm➔¨ Greater than 115 km/hr Hurricane

How does cyclone Occur?It develops over seas near the EquatorAir heated by sun rises very swiftly, which creates areas

of low pressureAs warm air rises, it becomes loaded with moisture which

condenses into massive thundercloudsCool air rushes into fill the void that left, but the constant

mixing of Earth on its axis the air bent inwards and spiral upwards with greater force The swirling wind rotates faster and faster forming huge circle which can be up to 2,000km across.

At the centre the storm is calm, cloudless area called the eye

As the cyclone builds up it begins to move. Winds around the eye can reach speeds up to 2000km/h

Damages due to cyclone➔Wind speed: Extensive damage to life and property due to wind speed, steep pressure gradient(topple fences, sheds, trees et.,)➔Natural hazard➔Many cyclones travel far inland and coastal areas➔Storm surges: Cyclone churns up the sea causing giant waves and flooding low lying coastal areas➔Torrential rain and Flooding: The rains from cyclones are heavy enough to cause serious flooding especially along the coastal line

Mitigative Measures The construction of building and life style can be modified to

minimise the effect Shelterbelt plantationPreservation/ regeneration of mangrove forestsStrengthening coastal Zone management frame

Preparedness: Risk Assessment A hazard map should be prepared for any given year and analysis could be used to estimate the probability of storms of cyclones of various intersections that may strike different parts of the county.

Analyses of climatologically records to determine how often tropical cyclones have struck- their intensities and locations.

History of wind strengths, frequencies, height and location of storm surges frequencies of flooding.

Avoid settling in places which are vulnerable to cyclone attack

Emergency helps available during cyclone period

Warning/Response System

The main objectives in a tropical cyclone warning are: To alert the people to the danger by announcing the

existence of a threat due to a cyclone.To identify the areas where people will be actively

threatened by cyclone and where communities should monitor further warning announcements,

To call the people to action by recommending specific preparedness activities, which may be part of, and integrated warning/response plan to protect vulnerable resources.

Early(Fore)Warning System

In India, the Indian Meteorological

Department has developed a four-stage warning

system for a cyclone.

First warning: is about the possibility of a cyclone

when a low pressure depression develops in oceans.

Alert Stage:This warning is given 48 hours prior to

the time when a cyclone is expected to hit the

land.

Second Warning stage: This is the stage when a cyclone

gets formed. The warning is given 24 hours before

the anticipated time of arrival of a cyclone.

Cyclone arrival: This warning is issued 12 hours before

a cyclone is due to hit the land. The warning gives

information about cyclone and will continue

until the winds subside.

In sea ports, danger signal are hoisted about the impending cyclone.

Cyclone Response●Fishermen are advised not to venture out into the sea. ●They should keep boats and rafts tied up in a safe place. ● Avoid taking shelters near old and damaged buildings or near trees. ● Do not touch power lines. One may get electrocuted

Volunteer to help people who may need assistance like:

o Bringing evacuated people back home and in recording damages

suffered

o Rendering first aid to the wounded

o Donating blood

o Locating places where dead bodies can be kept until

they are disposed off

o Organizing clearing-up so that normalcy returns as soon as possible

●Construction of cyclone shelters

Cyclone Recovery➢Compensation for loss of life and property .prise ➢ Repairs and construction of infrastructural facilities➢Rehabilitation of homeless➢Grant mercy relief to all affected people and relief for economic construction➢Camp-work and employment●Outside relief●Emergency relief to all the affected people

TSUNAMISTsunamis are Ocean Waves produced by

Earth Quakes or Underwater land slides.The word is Japanese and means “Harbor

Waves”Tsunami is a series of waves that can travel at

speeds from 400-600 mph in the open ocean. As the waves approach the coast, their speed

decreases, but their amplitude increases.Unusual wave heights of 10-20 ft high can be

very destructive and cause many deaths and injuries.

Causes of Tsunami Volcanoes, earthquakes and earth slides undersea

Where do Tsunami occur?Mostly occur in Pacific ocean which is surrounded by

the' ring of fire' that is highly volcano active and earthquake zone. It covers

From Alaska down to west coast of north and south America

East coast of Asia- China, Japan and RussiaOccur only in coastal regions and Island are the

main targets

Most deaths caused by Tsunamis are because of Drowning.Areas of greatest risks are-Less than 25 feet above sea level-Within 1 mile of the shore line.· Flooding· Contamination of Drinking WaterWater borne and food borne diseases· Fires from ruptured gas lines and tanks· Loss of vital Community Infrastructure [police, fire, medical]

2004 Tsunami of AsiaEpicenter near Sumatra in Indonesiaoccurred on 26th Dec, 20041,50,000 people were deadEarth quake measured was8.9 in Ritcher

scaleCoastal areas of India, Sri Lanka,

Malaysia and Maldives were affectedWave rose as high as six to ten meters.

Prediction and WarningTsunami are almost

undetectable warning system now

operates in the PacificSystem monitors sea

movements and can be used to map the path of tsunamis and estimate the rate of approach

notify the public and evacuations are undertaken

Landslides: A geological phenomenon which include wide

range of ground movement such as rock falls, deep failure of slopes and shallow debris flowThree distinct physical events occur during a landslide: the initial slope failure, the subsequent transport, and the final deposition of the slide materials.

Natural causes of Landslides:Earthquakes: Seismic activities have always been a main cause

of landslides. When earthquakes occur on areas with steep slopes, many times the soil slips causing landslides.

Heavy Rainfall: When sloped areas become completely saturated by heavy rainfall many times landslides can occur. Ground water pressure acting to destabilise the slope

Thunder and lightning may trigger failure of weak slopesErosion by rivers and ocean waves create oversteepened slopes

Human causes of Landslides:Deforestation and overgrazing: Without the aid of mechanical

root support the soil simply runs off when it contains too much water.

Mining: Mining operations that use blasting techniques often cause other areas that are at the risk of sliding to slide due to vibrations under the soil.

Trafic and road construction,urbanisation of hilly areaVibrations from machineryExtensive agriculture practice

CCauses of Land slides

Landslide Mitigation—How to Reduce the Effects of Landslides Non structural Measures

Creation of awareness among local population. Insurance Mud flow policies from National Flood

Insurance Program. Total avoidance of landslide hazard areas or by restricting,

prohibiting, or imposing conditions on hazard-zone activity. Local governments can reduce landslide effects through land-use

policies and regulations.By properly evaluating the hazard potential of a site, built or

unbuilt.

Mitigatory Measures: Structural MeasuresStabilizing the slope preventing water from rising in the

landslide mass by (1) covering the landslide with an impermeable membrane, (2) directing surface water away from the landslide, (3) draining ground water away from the landslide, and (4) minimizing surface irrigation.

Proper land use measures like Reforestation for the areas occupied by degraded vegetation·Construction of retaining walls ·Construction of channels or deflection walls to direct the mud flow around buildings. ●By avoiding construction on steep slopes and existing landslides, ●Solidification of loose granular material by chemical treatment●Construction●Bridging of unstable area by constructing piles, walls cribs or toe support fills●Creation of national parks, sanctuaries, biosphere reserve in landslide prone area●

Preparedness/responseForewarning before a landslide ● Springs or saturated grounds●New cracks or bulges in the ground can predict landslides. ●If concrete foundations crack or move, a landslide may occur. When poles, trees, or fences begin to lean, a slide may be on its way also. ●After a landslide, flooding may occur. Evacuate people to areas of Safety from Landslides •Areas that are safe from landslides are hard, non-jointed bedrock that has not moved in the past. •Areas that are flat lying and are away from slopes are also safe. ●Usually the tops of ridges and away from slope tops are safe areas. ●In an area prone to landslides, publish a special newspaper section with emergency information on landslides and debris flows.● Localize the information by including the phone numbers of local emergency services offices, the Red Cross, and hospitals. Organizing clearing-up so that normalcy returns as soon as possible

Landslide Recovery

· Replant damaged ground as soon as possible since erosion caused by

loss of ground cover can lead to flash flooding.

Compensation for loss of life and property .prise

● Repairs and construction of infrastructural facilities

●Rehabilitation of homeless

●Grant mercy relief to all affected people and relief for economic

construction

●Camp-work and employment

●Outside relief

●Emergency relief to all the affected people

·