DISASTER MANAGEMENT

EARTHQUAKES

Definition and Measurement

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

Most earthquakes result from the movement of one rock mass past another in response to tectonic forces.

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

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 as calculated from records of the event made on a calibrated seismograph.

In 1935, Charles Richter first defined local magnitude, and the Richter scale is commonly used today to describe an

earthquake's magnitude.

Earthquake Intensity.

In contrast, earthquake intensity is a measure of the effects of an earthquake at a particular place. It is determined from observations of the earthquake's effects on people, structures and the earth's surface.

Among the many existing scales, the Modified Mercalli Intensity Scale of 12 degrees, symbolized as MM, is frequently used 

Earthquake Hazards

Earthquake hazards can be categorized as either direct hazards or indirect hazards.

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. For large magnitude events, trembling has been

felt over more than 5 million sq. km. 

Site Risks

Some common site risks are:

(I) Slope Risks - Slope instability, triggered by strong shaking may cause landslides. Rocks or boulders can roll considerable distances.

(ii) Natural Dams - Landslides in irregular topographic areas may create natural dams which may collapse when they are filled.

This can lead to potentially catastrophic avalanches after strong seismic shaking.

(iii) Volcanic Activity - Earthquakes may be associated with potential volcanic activity and may occasionally be considered as precursory phenomena.

Explosive eruptions are normally followed by ash falls and/or pyroclastic flows, volcanic lava or mud flows, and volcanic gases.

CYCLONE.

The term "cyclone" refers to all classes of storms with low atmospheric pressure at the centre, are formed when an organized system of revolving winds, clockwise in the Southern Hemisphere, anti-clockwise in the Northern Hemisphere, develops over tropical waters.

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

 

Hurricane.

A hurricane is a low pressure, large scale weather system which derives its energy from the latent heat of condensation of water vapor over warm tropical seas. A mature hurricane may have a diameter ranging from 150 to 1000 km with sustained wind speeds often exceeding 180 km/hr near the centre with still higher gusts.

A unique feature of a hurricane is the Eye. The eye provides a convenient frame of reference for the system, and can be tracked with radar, aircraft or satellite.

Classification

The Saffir/Simpson scale is often used to categorize hurricanes based on their wind speed and damage potential. Five categories of hurricanes are recognized:

¨     Minimal, Moderate, Extensive, Extreme & Catastrophic

The destructive potential of a hurricane is significant due to the high wind speeds, accompanying torrential rains which produce

flooding, and storm surges along the coastline

TSUNAMIS

Tsunamis are Ocean Waves produced by Earth Quakes or Underwater land slides.

The word is Japanese and means “Harbor Waves”

Tsunami is actually 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.

Most deaths caused by Tsunamis are because of Drowning.

Associated risks include

·       Flooding

·       Contamination of Drinking Water

·       Fires from ruptured gas lines and tanks

·       Loss of vital Community Infrastructure [police, fire, medical]

·       Areas of greatest risks are

-Less than 25 feet above sea level

-Within 1 mile of the shore line.

Environmental Conditions left by the Tsunamis may contribute to the transmission of the following diseases

From Food or Water

·       Diarrhea illnesses;  Cholera, Acute Diarrhea, Dysentery

·       Hepatitis-A, Hepatitis-E

·       Typhoid Fever

·       Food borne illnesses;Bacterial;Viral;Parasitic;Non-infections;

From Animals or Mosquitoes

        Leptospirosis, Plague, Malaria, J.E, Dengue, Rabies

Respiratory Diseases;    Avian flu, Influenza, Measles

EFFECTS OF NUCLEAR HOLOCAUST

The effects of nuclear holocaust will result into blasts,

heat storms, secondary fires, fire, ionizing radiation and fall outs.

These effects fall into 3 categories;

1). Immediate, 2). Short term and 3). Long term effects.

¨     The immediate effects include blast effects, heat effects, electromagnetic pulse (EMP) effects and radiation effects.

¨     The short term effects include problems connected with water supply, sanitation, food, dispersal of excreta, wastes and dead bodies, break down of vector control measures and outbreak of infections. Radioactive contamination of water and food are major concerns. The affected area creates a lot of other problems for the survivors and the rescue teams.

Major problem among survivors is of bone marrow depression resulting in leucopenia, which increases their susceptibility to infections.

 

¨     Long term effects; the knowledge about the long-term effects is still incomplete. Some well known effects include radiation injuries due to radiation fallout, suppression of body immunity, chronic infection and other associated illnesses.

Persistent radiation hazards will lead to prolonged contamination of water supply, increased ultraviolet radiation, climatic and ecological disturbances, psychological disturbances and genetic abnormalities.

Current World Concern

In the light of the above facts the current world concern about the use of nuclear weapons is justified.

The world already possess an estimated total of 30,000 megatons of nuclear weapons with a total explosive power 50-100 times greater than that of all the explosives used during the Second World War.

Even if 1% of the nuclear weapons now possessed are used on urban populations, they can cause more deaths in a few hours than during the entire period of the Second World War.

The fundamental aspects of Disaster Management Program

¨     Disaster Prevention

¨     Disaster preparedness

¨     Disaster response

¨     Disaster mitigation

¨     Rehabilitation

¨     Reconstruction

 3 Fundamental Aspects of Disaster Management

 

1.    Disaster response

 

2.    Disaster Preparedness

 

3.    Disaster Mitigation   

These 3 aspects of Disaster Management corresponds to the

2 phases in the Disaster Cycle, ie,

1, Risk Reduction Phase, before a Disaster

 

2. Recovery Phase, after a Disaster   

 DISASTER RESPONSE

 OBJECTIVES

¨     Appropriate application of current technology can prevent much of the death, injury, and economic disruption resulting from disasters

¨     Morbidity and mortality resulting from disasters differ according to the type and location of the event.

¨     In any disaster, prevention should be directed towards reducing

(1) Losses due to the disaster event itself

(2) Losses resulting from the Mismanagement of disaster relief.

Therefore, the public health objectives of disaster management can be stated as follows:

1.    Prevent unnecessary morbidity, mortality, and economic loss resulting directly from the disaster.

2.    Eliminate morbidity, mortality, and economic loss directly attributable to Mismanagement of disaster relief efforts.

Nature and Extent of the Problem

Morbidity and mortality, which result from a disaster situation, can be classified into four types:

1.    Injuries, 

2.    Emotional stress,

3.    Epidemics of diseases,

4.    Increase in indigenous diseases.

The relative numbers of deaths and injuries differ on the type of disaster.

Injuries usually exceed deaths in explosions, typhoons, hurricanes, fires, famines, tornadoes, and epidemics.

Deaths frequently exceed injuries in landslides, avalanches, volcanic eruptions, tidal waves, floods, and earthquakes.

Disaster victims often exhibit emotional stress or the "disaster shock" syndrome. The syndrome consists of successive stages of shock, suggestibility, euphoria and frustration.

Each of these stages may vary in extent and duration depending on other factors. 

Epidemics are included in the definition of disaster; however, they can also be the result of other disaster situations.

Diseases, which may be associated with disasters, include

¨     specific food and/or water bone illnesses

     (e.g., typhoid, gastroenteritis and cholera),

¨     vector bone illnesses

    (e.g., plague and malaria),

¨     diseases spread by person-to-person contact

     (e.g., hepatitis A and shigellosis)

¨     Diseases spread by the respiratory route

     (e.g., measles and influenza).

·       The current status of environmental sanitation, disease surveillance, and preventive medicine has led to a significant reduction in the threat of epidemics following disaster.

 

·       Immunization programs are rarely indicated as a specific post disaster measure. 

·       A disaster is often followed by an increase in the prevalence of diseases indigenous to the area due to the disruption of medical and other health facilities and programs.

Morbidity and Mortality from Mismanagement of Relief

Ideally, attempts to mitigate the results of a disaster would not add to the negative consequences;

However, there have been many instances in which inappropriate and/or incomplete management actions taken after a disaster contributed to unnecessary morbidity, mortality, and a waste of resources.

Many of the Causalities and much more of the Destruction occurring to natural disaster are due to ignorance and neglect on the part of the individuals and public authorities.

There is a plethora of literature describing the inappropriate actions taken to manage past disasters. Many of the same mismanagement problems tend to recur.

¨     Physicians and nurses have been sent into disaster areas in numbers far in excess of actual need.

¨     Medical and paramedical personnel have often been hampered by the lack of the specific supplies they need to apply their skills to the disaster situation.

¨     In some disasters, available supplies have not been inventoried until well after the disaster, resulting in the importation of material which is used or needed.

In a study of past disaster mismanagement problems and their causes, these problems were categorized as follows:

1.    Inadequate appraisal of damages

2.    Inadequate problem ranking

3.    Inadequate identification of resources

4.    Inadequate location of resources

5.    Inadequate transportation of resources

6.    Inadequate utilization of resources

HAM Radio

Amateur Radio popularly known as HAM Radio is primarily a hobby and a service in which participants, called “Amateur Radio Operators” or "HAMs," use various types of radio/ wireless communications equipment to communicate with other radio amateurs for public service, recreation and self-training. At the same time, the HAMs often support the communities and administrators with emergency and disaster communications at the time of need.

For operating / possessing a Radio Station, Amateur Radio Operators have to obtain license after qualifying the specified examination conducted by Ministry of Communications & IT, Government of India. The subjects of examination are: -

i)    Morse Code (Transmission & Reception)

ii)   Communication Procedure

iii)  Basic Electronics. Amateur Radio License is granted to the candidates qualified in the examination by the Wireless Planning & Coordination (WPC) wing of Ministry of Communications & IT, Govt. of India after verification of their antecedents.

In the aftermath of Super Cyclone, 1999, HAM Radio was found useful in establishing communication with the affected areas in which HAMs from other states participated in this activity. Based on the said experience, initiatives have been taken to train the volunteers in HAM Radio with technical assistance of National Institute of Amateur Radio (NIAR), Hyderabad in order to enable them to qualify in the prescribed examination and obtain the required license to operate HAM stations in our State.

DISASTER MANAGEMENT

Andhra Pradesh is exposed to cyclones, storm surges, floods and droughts. A moderate to severe intensity cyclone can be expected to make landfall every two to three years. About 44 percent of the state is vulnerable to tropical storms and related hazards.

In India, the cyclones develop in the pre-monsoon (April to May) and post-monsoon seasons (October to December), but most of them tend to form in the month of November.

Cyclones on the east coast originate in the Bay of Bengal, the Andaman Sea or the South China Sea, and usually reach the coastline of Tamil Nadu, Andhra Pradesh, Orissa and West Bengal, which are the most vulnerable to these types of hazards. Two of the deadliest cyclones of this century, with fatalities of about 10,000 people in each case, took place in Orissa and Andhra Pradesh during October 1971 and November 1977 respectively. The super cyclone of Orissa in 1999 caused large scale damage to life and property.

Along the Andhra coast, the section between Nizampatnam and Machilipatnam is the most prone to storm surges. Vulnerability to storm surges is not uniform along Indian coasts. The following segments of the east coast of India are most vulnerable to high surges

1.     North Orissa, and West Bengal coasts.

2.     Andhra Pradesh coast between Ongole and Machilipatnam.

3.     Tamil Nadu coast, south of Nagapatnam.

The states bordering the Arabian Sea on the west coast are not completely safe either, as Kerala, Gujarat - and to a lesser extent Maharashtra - are also prone to cyclones. With a frequency of four cyclones per year, one of which usually becomes severe, the Bay of Bengal accounts for seven percent of the annual tropical cyclone activity worldwide.

Despite this relatively low percentage, the level of human and property loss that cyclones cause around the Bay is very high. Once the cyclones enter the mainland, they give way to heavy rains which often translate into floods, as it was the case with the damaging cyclone-induced floods in the Godavari delta, in August of 1986.

Many drought prone areas adjacent to coastal districts in eastern maritime states are thus vulnerable to flash floods originated by the torrential rains induced by the cyclonic depression. In addition to cyclones and its related hazards, monsoon depressions over the north and central areas of the Bay of Bengal move until reaching north and central India, including portions of Andhra Pradesh, bringing heavy to very heavy rains and causing floods in the inland rivers between June and September.

In Andhra traditionally, the flood problem had been confined to the flooding of smaller rivers. But the drainage problem in the coastal delta zones has worsened, multiplying the destructive potential of cyclones and increasing flood hazards. A critical factor is maintenance of irrigation systems. On several occasions, deaths have been caused by breaches in tanks and canals as well as over-flooding caused by silting and growth of weeds.

Effect of Repeated Disasters

The regular occurrence of Disasters both Natural and Man made in Coastal Andhra Pradesh in India has had a series of repercussions on the state country’s Economy, its development policies and political equilibrium and daily life of millions of Indians.

Andhra Pradesh is battered by every kind of natural disaster: cyclones, floods, earthquakes and drought. The coastal region suffers repeated cyclones and floods. The 1977 cyclone and tidal wave, which resulted in great loss of life, attracted the attention of the central and state Governments of India and the international donor communities, as did those of 1979, 1990 and 1996. The floods in the Godavari and Krishna Rivers caused havoc in the East and West Godavari and Krishna districts.

Earthquakes in the recent past have occurred along and off the Andhra Pradesh coast and in regions in the Godavari river valley. Mild tremors have also hit the capital city of Hyderabad, for example in September 2000.

Social and economic life of AP's population is characterized by recurring natural disasters. The state is exposed to cyclones, storm surges, floods, and droughts. According to the available disaster inventories, AP is the state that has suffered the most from the adverse effects of severe cyclones. It has been estimated that about 44 percent of AP's total territory is vulnerable to tropical storms and related hazards, while its coastal belt is likely to be the most vulnerable region in India to these natural phenomena. Khamman district, in the Telengana region, is affected by monsoon floods, along with five districts in Coastal AP. Four districts in Rayalaseema and five in Telengana experience drought. Along the coastline, the section between Nizampatnam and Machilipatnam is the most prone to storm surges. The fertile Delta areas of the Godavari and the Krishna rivers, which contribute substantially to the state's economic prosperity, face flood and drainage problems, and more so in the aftermath of cyclones.

More than sixty cyclones have affected AP this century. The incidence of cyclones seems to have increased in the past decades, to the extent that severe cyclones have become a common event occurring every two to three years, repeatedly and severely affecting the state's economy while challenging its financial and institutional resources3. Almost2 9 million people are vulnerable to cyclones and their effects in Coastal AP, 3.3 million of who belong to communities located within five km of the seashore. The deadliest cyclone in the last twenty years took place in November 1977 killing about 10,000 people. More recently, the May 1990 cyclone, with a death toll close to 1,000 people, caused about US$1.25 billion in damage in ten districts, including the entire coast. Between 1977 and 1992, about 13,000 lives and 338,000 cattle were lost due to cyclones and floods, and nearly 3.3 million houses damaged.

May cyclones are relatively rare in the region, and only about 13 have affected AP in this month this century. However, when they badly hit the Delta areas, as it happened in 1979 in the Krishna district - where 80 percent of the casualties occurred - the population in danger may be higher than usual. May is rice harvesting season, and a good number of itinerant laborers come to the delta from less fertile areas of AP in search of work. Since they lack awareness of the area's most prevalent hazards, this migrant population is more vulnerable than the permanent delta residents. Similarly, entire families have come to the delta districts to engage in activities related to shrimp farming, which has taken off recently in the area. They are involved in the collection of fingerlings, living for several months a year in makeshift shelters along the marshes. The warnings may not reach them on time, and even when they do, their inexperience renders them highly vulnerable.

The Godavari and the Krishna rivers have well-defined stable courses, and their natural and man-made banks have usually been capable of carrying flood discharges, with the exception of their delta areas. Traditionally, the flood problem in AP had been confined o the spilling of smaller rivers and the submersion of marginal areas surrounding Kolleru Lake. However, the drainage problem in the delta zones of the coastal districts has worsened, thereby multiplying the destructive potential of cyclones and increasing flood hazards. Moreover, when a storm surge develops, as it was the case during the severe November 1977, May 1990 and November 1996 cyclones, threats to humans and property multiply as the sea water may inundate coastal areas which are already being subjected to torrential rains. Finally, a critical additional factor affecting the flood management and the irrigation systems is the lack of maintenance. On several occasions, such as the May 1979 cyclone, most of the deaths were occasioned by breaches to the chains of tanks and canals, and over-flooding due in part to the choking of drains by silting and growth of weeds.

Nearly half of AP vulnerable to floods

Andhra Pradesh witnesses severe cyclones almost every two to three years. About 44 per cent of the State is vulnerable to tropical storms and related hazards. The coastal belt is said to be the most vulnerable region in India to these natural phenomena.

Cyclones on the east coast originate in the Bay of Bengal, the Andaman Sea or the South China Sea, and usually reach the coastline of Tamil Nadu, Andhra Pradesh, Orissa and West Bengal, which are the most vulnerable to these types of hazards. Two of the deadliest cyclones of this century, with fatalities of about 10,000 people in each case, took place in Orissa and Andhra Pradesh during October 1971 and November 1977 respectively. The super cyclone of Orissa in 1999 caused large-scale damage to life and property.

Along the Andhra coast, the section between Nizampatnam and Machilipatnam is the most prone to storm surges and the loss of human and property caused by cyclones around the Bay is very high. Once the cyclones enter the mainland, they give way to heavy rains which often translate into floods. This season is no exception. Heavy rains coupled with inflows from Karnataka induced floods causing some damage to crops in Mahbubnagar, Adilabad, Prakasam district, Vijayawada, Krishna and Guntur.

Many drought-prone areas adjacent to coastal districts in eastern maritime states are thus vulnerable to flash floods originated by the torrential rains induced by the cyclonic depression. In addition to cyclones and its related hazards, monsoon depressions over the north and central areas of the Bay of Bengal move until reaching north and central India, including parts of Andhra Pradesh, bringing heavy to very heavy rains and causing floods in the inland rivers between June and September.

In Andhra traditionally, the flood problem has been confined to the flooding of smaller rivers. But the drainage problem in the coastal delta zones has worsened, multiplying the destructive potential of cyclones and increasing flood hazards. A critical factor is maintenance of irrigation systems. On several occasions, deaths were caused by breaches in tanks and canals as well as over-flooding caused by silting and growth of weeds.

Effect of repeated disasters

The regular occurrence of disasters both natural and man-made in Coastal region has had a series of repercussions on the State’s economy, its development policies and political equilibrium and daily life of millions of people. The coastal region suffers repeated cyclones and floods.

The 1977 cyclone and tidal wave, which resulted in great loss of life, attracted the attention of the Central and State Governments and the international donor communities, as did those of 1979, 1990 and 1996. The floods in the Godavari and Krishna Rivers caused havoc in the East and West Godavari and Krishna districts.

Along the coastline, the section between Nizampatnam and Machilipatnam is the most prone to storm surges. The fertile delta areas of the Godavari and the Krishna rivers, which contribute substantially to the State's economic prosperity, face flood and drainage problems, and more so in the aftermath of cyclones.
More than sixty cyclones hit AP this century.

The incidence of cyclones seems to have increased in the past decades, to the extent that severe cyclones have become a common event occurring every two to three years, repeatedly and severely affecting the state's economy.

May cyclones are relatively rare in the region, and only about 13 affected AP in this century. However, when they badly hit the delta areas, as it happened in 1979 in the Krishna district - where 80 per cent of the casualties occurred - the population may be in higher danger than usual. May is the rice harvesting season, and a good number of itinerant laborers come to the delta from less fertile areas of AP in search of work.

Since they lack awareness of the area's most prevalent hazards, this migrant population is more vulnerable than the permanent delta residents. Traditionally, the flood problem in AP had been confined to the spilling of smaller rivers and the submersion of marginal areas.

However, the drainage problem in delta zones of the coastal districts has worsened, thereby multiplying the destructive potential of cyclones and increasing flood hazards.

Moreover, when a storm surge develops, as it was the case during the November 1977, May 1990 and November 1996 cyclones, threats to humans and property multiply as the sea water inundates coastal areas which are already being subjected to torrential rains.