Disaster Preparedness & Planning Management Syllabus PDF

SYLLABUS UNIT – I Introduction: Concepts and definitions: disaster, hazard, vulnerability, resilience, risks severity, frequency and details, capacity, impact, prevention, mitigation. UNIT – II Disasters: Disasters classification; natural disasters (floods, draugh...

SYLLABUS UNIT – I Introduction: Concepts and definitions: disaster, hazard, vulnerability, resilience, risks severity, frequency and details, capacity, impact, prevention, mitigation. UNIT – II Disasters: Disasters classification; natural disasters (floods, draught, cyclones, volcanoes, earthquakes, tsunami, landslides, coastal erosion, soil erosion, forest fires etc.); manmade disasters (industrial pollution, artificial flooding in urban areas, nuclear radiation, chemical spills, transportation accidents, terrorist strikes, etc.); hazard and vulnerability profile of India, mountain and coastal areas, ecological fragility. UNIT – III Disaster Impacts: Disaster impacts (environmental, physical, social, ecological, economic, political, etc.); health, psycho-social issues; demographic aspects (gender, age, special needs); hazard locations; global and national disaster trends; climate change and urban disasters. UNIT – IV Disaster Risk Reduction (DRR): Disaster management cycle – its phases; prevention, mitigation, preparedness, relief and recovery; structural and non- structural measures; risk analysis, vulnerability and capacity assessment; early warning systems, Post disaster environmental response (water, sanitation, food safety, waste management, disease control, security, communications); Roles and responsibilities of government, community, local institutions, NGOs and other stakeholders; Policies and legislation for disaster risk reduction, DRR programmes in India and the activities of National Disaster Management Authority. UNIT – V Disasters, Environment and Development: Factors affecting vulnerability such as impact of developmental projects and environmental modifications (including of dams, land use changes, urbanization etc.), sustainable and environmental friendly recovery; reconstruction and development methods. Disaster Preparedness & Planning Management Riyaz Mohammed UNIT – I Introduction: Concepts and Definitions: Disaster, Hazard, Vulnerability, Resilience, Risks severity, Capacity, Prevention, Mitigation. 1.1 – Disaster: Definition: An event, natural or human made sudden or progressive, which impacts with such severity that the affected community has to respond by taking exceptional measures! Or A disaster can be defined as “A serious disruption in the functioning of the community or a society causing wide spread material, economic, social or environmental losses which exceed the ability of the affected society to cope using its own resources”. Or The Disaster Management Act, 2005 defines disaster as “a catastrophe, mishap, calamity or grave occurrence in any area, arising from natural or manmade 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”. Or The United Nations defines disaster as “the occurrence of sudden or major misfortune which disrupts the basic fabric and normal functioning of the society or community”. Disaster Background: Disasters are as old as human history but the dramatic increase and the damage caused by them in the recent past have become a cause of national and international concern. Over the past decade, the number of natural and man‐made disasters has climbed inexorably. From 1994 to 1998, reported disasters average was 428 per year but from 1999 to 2003, this figure went up to an average of 707 disaster events per year showing an increase of about 60 per cent over the previous years. 1|Page Disaster Preparedness & Planning Management Riyaz Mohammed The biggest rise was in countries of low human development, which suffered an increase of 142 per cent. Disasters are not new to mankind. They have been the constant, though inconvenient, companions of the human beings since time immemorial. Disasters can be natural or human‐made. Earthquake, cyclone, hailstorm, cloud‐burst, landslide, soil erosion, snow avalanche, flood etc. are the examples of natural disasters while fire, epidemics, road, air, rail accidents and leakages of chemicals/nuclear installations etc. fall under the category of human‐made disasters. Relationship: Hazard x Vulnerability = Disaster Classification: Disaster can classified as: 1. Natural (Resulting from Natural Forces). 2. Man-made (Resulting from Human Decision). 3. Hybrid (resulting from both natural and man made) 1. Natural Disaster classified in to: i. Resulting from phenomenon beneath the earth surface (E.g. Earthquake, tsunami, Volcano) At the earth surface – landslide & Avalanche. ii. Resulting from meteorological/hydrological phenomenon (e.g. Wind storm, cyclones, hurricane, typhoon, tornados, flood, drought, heat wave). iii. Biological phenomenon (E.g. epidemics, infestation). 2. Man-made Disaster classified in to: i. Socio –technical disaster. ii. Warfare Disaster. i. Socio technical disaster can occur in following situation:  Technological (e.g. gas leakage, fire during industrial activity).  Transport failure (e.g. Air crash, Road/rail accidents).  Stadia and public place failure (fire, structural, collapse, crushing). ii. Warfare Disaster classified in Interstate conflict and international conflict, which can further include – chemical, biological, nuclear wars. 3. Hybrid Disaster are result of natural forces and human action (e.g. excessive deforestation). 2|Page Disaster Preparedness & Planning Management Riyaz Mohammed India Disaster Scenario: India due to its geo‐climatic and socio‐economic condition is prone to various disasters. During the last thirty years’ time span the country has been hit by 431 major disasters resulting into enormous loss to life and property. According to the Prevention Web statistics, 143039 people were killed and about 150 crore were affected by various disasters in the country during these three decades. The disasters caused huge loss to property and other infrastructures costing more than US $ 4800 crore. The most severe disasters in the country and their impact in term of people affected, lives lost and economic damage is given in the In India, the cyclone which occurred on 25th November, 1839 had a death toll of three lakh people. The Bhuj earthquake of 2001 in Gujarat and the Super Cyclone of Orissa on 29th October, 1999 are still fresh in the memory of most Indians. The most recent natural disaster of a cloud burst resulting in flash floods and mudflow in Leh and surrounding areas in the early hours of 6th August, 2010, caused severe damage in terms of human lives as well as property. There was a reported death toll of 196 persons, 65 missing persons, 3,661 damaged houses and 27,350 hectares of affected crop area. Floods, earthquakes, cyclones, hailstorms, etc. are the most frequently occurring disasters in India. 3|Page Disaster Preparedness & Planning Management Riyaz Mohammed Disasters – Global Scenario: Disasters ‐ natural or human‐made are common throughout the world. Disasters continue to occur without warning and are perceived to be on an increase in their magnitude, complexity, frequency and economic impact. Hazards pose threats to people and assume serious proportions in the under developed countries with dense population. During the second half of the 20th century, more than 200 worst natural disasters occurred in the different parts of the world and claimed lives of around 1.4 million people. Losses due to natural disasters are 20 times greater (as % of GDP) in the developing countries than in industrialized one. Asia tops the list of casualties due to natural disasters. Figure shows the Regional distribution of disasters by type, as prepared by Centre for Research on Epidemiology of Disaster. 4|Page Disaster Preparedness & Planning Management Riyaz Mohammed There have been several natural, as well as, man‐made disasters. Records of natural disasters can be traced way back to 430 B.C. when the Typhus epidemic was reported in Athens. Ten deadliest natural disasters recorded in the world are dated back to 1556 when an earthquake in Shaanxi province of China occurred on 23rd January, 1556 and 8,30,000 casualties were recorded. List of ten deadliest disasters which have occurred across the world and in India in the known history and in the last century may be seen from the respectively. World Disaster 5|Page Disaster Preparedness & Planning Management Riyaz Mohammed Indian Disasters 6|Page Disaster Preparedness & Planning Management Riyaz Mohammed Impact of Disasters: 1. Loss of lives. 2. Loss to Property and infrastructure. 3. Damage to livelihood. 4. Economic Loss. 5. Environmental Damage- Flora & Fauna. 6. Sociological & Psychological after effects. 1.2 – Hazard: Definition: “Hazards are defined as physical phenomena that pose a threat to the people, structures or economic assets and which may cause a disaster.” Earthquake, floods, tsunami etc are all hazards and we can prevent them from becoming disasters. Or Hazard may be defined as “a dangerous condition or event that threat or have the potential for causing injury to life or damage to property or the 7|Page Disaster Preparedness & Planning Management Riyaz Mohammed environment.” The word ‘hazard’ owes its origin to the word ‘hasard’ in old French and ‘az‐zahr’ in Arabic meaning ‘chance’ or ‘luck’. Types/Classification: Hazards can be grouped into two broad categories namely: 1. Natural hazards. 2. Manmade hazards. 1. Natural hazards are hazards which are caused because of natural phenomena (hazards with meteorological, geological or even biological origin). Examples of natural hazards are cyclones, tsunamis, earthquake and volcanic eruption which are exclusively of natural origin. Landslides, floods, drought, fires are socio‐natural hazards since their causes are both natural and manmade. For example flooding may be caused because of heavy rains, landslide or blocking of drains with human waste. 2. Manmade hazards are hazards which are due to human negligence. Manmade hazards are associated with industries or energy generation facilities and include explosions, leakage of toxic waste, pollution, dam failure, wars or civil strife etc. The list of hazards is very long. Many occur frequently while others take place occasionally. Hazards can be grouped as, 8|Page Disaster Preparedness & Planning Management Riyaz Mohammed 1.3 – Vulnerability: Definition: Vulnerability may be defined as “The extent to which a community, structure, services or geographic area is likely to be damaged or disrupted by the impact of particular hazard, on account of their nature, construction and proximity to hazardous terrains or a disaster prone area.” It is the likely extent of damage due to a hazard. Key Concept of Vulnerability: Types of Vulnerability: Vulnerabilities can be categorized into: 1. Physical vulnerability. 2. Socio‐economic vulnerability. 1. Physical vulnerability: It includes notions of who and what may be damaged or destroyed by natural hazard such as earthquakes or floods. It is based on the physical condition of people and elements at risk, such as buildings, infrastructure etc; and their proximity, location and nature of the hazard. It also relates to the technical capability of building and structures to resist the forces acting upon them during a hazard event. The settlements which are located in hazardous slopes. Figure below shows the settlements which are located in hazardous slopes. Many landslide and flooding disasters are linked to what you see in the figure 9|Page Disaster Preparedness & Planning Management Riyaz Mohammed below. Unchecked growth of settlements in unsafe areas exposes the people to the hazard. In case of an earthquake or landslide the ground may fail and the houses on the top may topple or slide and affect the settlements at the lower level even if they are designed well for earthquake forces. Fig: Site after pressures from population growth and urbanization 2. Socio‐economic vulnerability: The degree to which a population is affected by a hazard will not merely lie in the physical components of vulnerability but also on the socio‐ economic conditions. The socioeconomic condition of the people also determines the intensity of the impact. For example, people who are poor and living in the sea coast don’t have the money to construct strong concrete houses. They are generally at risk and lose their shelters whenever there is strong wind or cyclone. Because of their poverty they too are not able to rebuild their houses. 10 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed 1.4 – Resilience: “Resilire” (Latin word) ‐ to bounce back. Engineering resilience: The time taken by a system to bounce‐back from shocks. Ecological resilience: The extent of disturbance a system can take without undergoing structural change. Disaster Resilience is the ability of individuals, communities, organizations and states to adapt to and recover from hazards, shocks or stresses without compromising long‐term prospects for development. According to the Hyogo Framework for Action (UNISDR, 2005), disaster resilience is determined by the degree to which individuals, communities and public and private organizations are capable of organizing themselves to learn from past disasters and reduce their risks to future ones, at international, regional, national and local levels. Disaster resilience is part of the broader concept of resilience – ‘the ability of individuals, communities and states and their institutions to absorb and recover from shocks, whilst positively adapting and transforming their structures and means for living in the face of long‐term changes and uncertainty’. Elements of a resilience framework: In practice, DFID’s framework (DFID, 2011a, 6‐7; diagram below) depicts the core elements of disaster resilience as follows: 1. Context: Whose resilience is being built – such as a social group, socio‐economic or political system, environmental context or institution. 2. Disturbance: What shocks (sudden events like conflict or disasters) and/or stresses (long‐term trends like resource degradation, urbanization, or climate change) the group aims to be resilient to. 3. Capacity to respond: The ability of a system or process to deal with a shock or stress depends on exposure (the magnitude of the shock or stress), sensitivity (the degree to which a system will be affected by, or will respond to, a given shock or stress), and adaptive capacity (how well it can adjust to a disturbance or moderate damage, take advantage of opportunities and cope with the consequences of a transformation). 11 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed 4. Reaction: A range of responses are possible, including: bounce back better, where capacities are enhanced, exposures are reduced, and the system is more able to deal with future shocks and stresses; bounce back, where pre‐existing conditions prevail; or recover, but worse than before, meaning capacities are reduced. In the worst‐case scenario, the system collapses, leading to a catastrophic reduction in capacity to cope with the future. 1.5 – Risk: Definition: The probability of harmful consequences or expected losses resulting from interaction between natural or human induced hazards and vulnerable conditions. Or Risk is a “measure of the expected losses due to a hazard event occurring in a given area over a specific time period. Risk is a function of the probability of particular hazardous event and the losses each would cause.” 12 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed Level of risk: The level of risk depends upon: 1. Nature of the hazard. 2. Vulnerability of the elements which are affected. 3. Economic value of those elements A community/locality is said to be at ‘risk’ when it is exposed to hazards and is likely to be adversely affected by its impact. Whenever we discuss ‘disaster management’ it is basically ‘disaster risk management’. Disaster risk management includes all measures which reduce disaster related losses of life, property or assets by either reducing the hazard or vulnerability of the elements at risk. Key concept: Hazard * Vulnerability/Capacity = Risk. 13 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed 1. Preparedness: This protective process embraces measures which enable governments, communities and individuals to respond rapidly to disaster situations to cope with them effectively. Preparedness includes the formulation of viable emergency plans, the development of warning systems, the maintenance of inventories and the training of personnel. It may also embrace search and rescue measures as well as evacuation plans for areas that may be at risk from a recurring disaster. Preparedness therefore encompasses those measures taken before a disaster event which are aimed at minimizing loss of life, disruption of critical services, and damage when the disaster occurs. 2. Mitigation: Mitigation embraces measures taken to reduce both the effect of the hazard and the vulnerable conditions to it in order to reduce the scale of a future disaster. Therefore mitigation activities can be focused on the hazard itself or the elements exposed to the threat. Examples of mitigation measures which are hazard specific include water management in drought prone areas, relocating people away from the hazard prone areas and by strengthening structures to reduce damage when a hazard occurs. 14 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed In addition to these physical measures, mitigation should also aim at reducing the economic and social vulnerabilities of potential disasters. Elements at Risk: Persons, buildings, crops or other such like societal components exposed to known hazard, which are likely to be adversely affected by the impact of the hazard. 1.6 – Capacity: Definition: Capacity is the resources of individuals, households and communities to cope with a threat or resist the impact of a hazard. Or Capacity can be defined as “resources, means and strengths which exist in households and communities and which enable them to cope with, withstand, prepare for, prevent, mitigate or quickly recover from a disaster”. People’s capacity can also be taken into account. Capacities could be: 1. Physical Capacity: People whose houses have been destroyed by the cyclone or crops have been destroyed by the flood can salvage things from their homes and from their farms. Some family members have skills, which enable them to find employment if they migrate, either temporarily or permanently. 2. Socio‐economic Capacity: In most of the disasters, people suffer their greatest losses in the physical and material realm. Rich people have the capacity to recover soon because of their wealth. In fact, they are seldom hit by disasters because they live in safe areas and their houses are built with stronger materials. However, even when everything is destroyed they have the capacity to cope up with it. Hazards are always prevalent, but the hazard becomes a disaster only when there is greater vulnerability and less of capacity to cope with it. In other words the frequency or likelihood of a hazard and the vulnerability of the community increases the risk of being severely affected. 15 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed Hazard * Vulnerability/Capacity = Risk. Physical phenomena that pose a threat to the people * Extent to which the community, structure can get damaged – Available and potential resources = Risk (Probability of disaster occurrence). 1.7 – Prevention: Definition: Activities to avoid the adverse impact of hazards and means to check from turning into disasters. Examples: Avoiding construction in seismically active areas, landslide prone areas and flood planes. 1.8 – Mitigation: Introduction:  Mitigation means measures aimed at reducing the risk, impact or effects of a disaster or threatening disaster situation Measures taken in advance of a disaster aimed at reducing its impact on society and the environment.  Learning from the past disaster.  Incorporating the learning in present scenario.  Building back better to reduce the impact of future disasters. 16 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed Mitigation Measures: 1. Structural Measures: i. Multi-hazard resistant buildings. ii. Shelters. iii. Retrofitting. iv. Modernizing early warning system. 2. Non-structural Measures: i. Awareness generation. ii. Training and capacity building. iii. Policy and regulations. iv. Mock drills and demos. v. Effective dissemination of early warning. vi. Development of state, district village plans. vii. Building byelaws Revision. ****** 17 | P a g e  Disaster Preparedness & Planning Management Riyaz Mohammed UNIT – II Disasters: Disasters classification; Natural disasters (Floods, Drought, Cyclones, Volcanoes, Earthquakes, Tsunami, Landslides, Coastal erosion, Soil erosion, Forest fires etc.); Manmade disasters (Industrial pollution, Artificial flooding in urban areas, Nuclear radiation, Chemical spills, Transportation accidents, Terrorist strikes, etc.); Hazard and Vulnerability profile of India, Mountain and Coastal areas. 2.1 – Disasters Classification [Or] Type of Disasters: There are two types of disasters namely: 1. Natural disasters. 2. Manmade disasters. Both natural and man-made disasters which have devastating input resulting loss of human life, loss of livelihoods, property and environmental degradation. Disasters disrupts normal functioning of society and leave long lasting impact. 1. Natural disasters: Certain disasters occur in nature, without human provocation. They are listed below: i. Floods. ii. Drought. iii. Cyclones. iv. Volcanoes. v. Earthquakes. vi. Tsunami. vii. Landslides. viii. Coastal erosion. ix. Soil erosion. x. Forest fires etc. 2. Manmade or Man Induced or Artificial or Anthropogenic disasters: Certain disasters occur in nature by humans activities. They are listed below: i. Industrial pollution. ii. Artificial flooding in urban areas. iii. Nuclear radiation. iv. Chemical spills. 18 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed v. Transportation accidents. vi. Terrorist strikes, etc. Note: Both Natural & Manmade disasters are explained clearly in sections 2.2 & 2.3 2.2 – Natural Disasters (Floods, Drought, Cyclones, Volcanoes, Earthquakes, Tsunami, Landslides, Coastal Erosion, Soil Erosion & Forest Fires Etc.): Natural disasters: Natural disasters are disasters that occur as a natural process of weather patterns or other factors affecting Earth. Or Natural disasters occur in nature, without human provocation. Types of Natural disasters: These types of natural disasters can include: 1. Floods. 2. Drought. 3. Cyclones. 4. Volcanoes. 5. Earthquakes. 6. Tsunami. 7. Landslides or mudslides. 8. Coastal erosion. 9. Soil erosion. 10.Forest fires etc. FLOODS Definition: Flood is a state of high water level along a river channel or on the coast that leads to inundation of land, which is not usually submerged. Floods may happen gradually and also may take hours or even happen suddenly without any warning due to breach in the embankment, spill over, heavy rains etc. Or Floods are sudden and temporary inundation of a large area as an overflowing of rivers or reservoirs. 19 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed Or A flood occurs when the volume of water in the river becomes greater than bank‐full stage the extra water spills over the banks and spreads in sheets all along and away from the banks governed by available slope. This condition is called flood. Introduction: Floods are relatively slow in occurrences and often, occur in well‐identified regions and within expected time in a year. Floods occur commonly when water in the form of surface run‐off exceeds the carrying capacity of the river channels and streams and flows into the neighbouring low‐lying flood plains. At times, this even goes beyond the capacity of lakes and other inland water bodies in which they flow. Floods can also be caused due to a storm surge (in the coastal areas), high intensity rainfall for a considerably longer time period, melting of ice and snow, reduction in the infiltration rate and presence of eroded material in the water due to higher rate of soil erosion. Though floods occur frequently over wide geographical area having disastrous ramifications in many parts of the world, floods in the South, Southeast and East Asian countries, particularly in China, India and Bangladesh, are frequent and equally disastrous. Types/Classification of Floods: According to their duration flood can be divided into different categories: 1. Slow‐Onset Floods: Slow Onset Floods usually last for a relatively longer period, it may last for one or more weeks, or even months. 20 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed 2. Rapid‐Onset Floods: Rapid Onset Floods last for a relatively shorter period, they usually last for one or two days only. 3. Flash Floods: Flash Floods may occur within minutes or a few hours after heavy rainfall, tropical storm, failure of dams or levees or releases from dams, and it causes the greatest damages to society. Magnitude & Frequency of Flood:  The magnitude of a flood is generally indicated by the discharge of water from a channel at a particular point. The discharge of flow is commonly indicated by means of a hydrograph.  As the name indicates, a hydrograph is a plot between discharge of a stream at a particular place in cubic meters/sec or cubic feet/sec over a period of time (day/week/month/year). A flood is often indicated by the Peak in a hydrograph.  If we have hydrographs of a river for longer periods (or years) then it can be used for flood prediction studies.  If we have longer periods of hydrographs, the frequency of flood i.e. its recurrence or periodicity can be predicted.  If a flood has return period of 10 years it means it occurs once in 10 years. Flood Hazard in India/Distributional Pattern of Floods in India: Floods occur in almost all the river basins of the country. Various states of India face heavy loss of lives and property due to recurrent floods. National Flood Commission identified 40 million hectares of land as flood‐prone in India. 21 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed Assam, West Bengal and Bihar are among the high flood‐prone states of India. Apart from these, most of the rivers in the northern states like Punjab and Uttar Pradesh, are also vulnerable to occasional floods. It has been noticed that states like Rajasthan, Gujarat, Haryana and Punjab are also getting inundated in recent decades due to flash floods. This is partly because of the pattern of the monsoon and partly because of blocking of most of the streams and river channels by human activities. Sometimes, Tamil Nadu experiences flooding during November‐ January due to the retreating monsoon. Most of the flood affected areas lie in the Ganga basin, Brahmaputra basin (comprising of Barak, Tista, Torsa, Subansiri, Sankosh, Dihang and Luhit), the north western river basin (comprising Jhelum, Chenab, Ravi, Sutlej, Beas and the Ghagra), peninsular river basin (Tapti, Narmada, Mahanadi, Baitarani, Godavari, krishna, Pennar and the Kaveri) and the coastal regions of Andhra Pradesh, Tamilnadu, orissa and Kerala. Assam, Uttar Pradesh, Bihar and Orissa are some of the states who have been severely prone to floods. Our country receives an annual rainfall of 1200 mm, 85% of which is concentrated in 3‐4 months i.e June to September. Due to the intense and periodic rain, most of the rivers of the country are fed with huge quantity of water, much beyond their carrying capacity. 22 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed Monitoring of Floods: Anticipating floods before they occur allows for precautions to be taken and people to be warned so that they can be prepared in advance for flooding conditions. In order to make the most accurate flood forecasts for waterways, it is best to have a long time‐series of historical data that relates stream flows to measure past rainfall events. Radar estimates of rainfall and general weather forecasting techniques are also important components of good flood forecasting. 23 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed Possible Risk Reduction Measures: 1. Mapping of the flood prone areas is a primary step involved in reducing the risk of the region. Historical records give the indication of the flood inundation areas and the period of occurrence and the extent of the coverage. Warning can be issued looking into the earlier marked heights of the water levels in case of potential threat. In the coastal areas the tide levels and the land characteristics will determine the submergence areas. Flood hazard mapping will give the proper indication of water flow during floods. 2. Land use control will reduce danger of life and property when waters inundate the floodplains and the coastal areas. The number of casualties is related to the population in the area at risk. In areas where people already have built their settlements, measures should be taken to relocate to better sites so as to reduce vulnerability. No major development should be permitted in the areas which are subjected to high flooding. Important facilities like hospitals, schools should be built in safe areas. In urban areas, water holding areas can be created like ponds, lakes or low‐lying areas. 3. Construction of engineered structures in the flood plains and strengthening of structures to withstand flood forces and seepage. The buildings should be constructed on an elevated area. If necessary build on stilts or platform. Flood Control aims to reduce flood damage. This can be done by decreasing the amount of runoff with the help of reforestation (to increase absorption could be a mitigation strategy in certain areas), protection of vegetation, clearing of debris from streams and other water holding areas, conservation of ponds and lakes etc. Flood Diversion include levees, embankments, dams and channel improvement. Dams can store water and can release water at a manageable rate. But failure of dams in earthquakes and operation of releasing the water can cause floods in the lower areas. Flood Proofing reduces the risk of damage. Measures include use of sand bags to keep flood water away, blocking or sealing of doors and windows of houses etc. Houses may be elevated by building on raised land. Buildings should be constructed away from water bodies. 4. Flood Management: In India, systematic planning for flood management commenced with the Five Year Plans, particularly with the launching of National Programme of Flood Management in 1954. During the last 48 years, different methods of flood protection structural as well as non-structural have 24 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed been adopted in different states depending upon the nature of the problem and local conditions. Causes of Floods: 1. Natural Causes: i. Heavy Rainfall: Heavy rainfall raises the water level. When the water level is higher than the river bank or the dams, the water comes out from the river, and there will be flooding. ii. Snowmelt: Because of global warming, the temperature of current years is higher than the temperature of years ago. The ice caps melt in summer, and the water goes into the sea. The water raises the sea level, and makes the river level rise. When river level rises, flooding may occur. iii. Relief (release): Flooding often occurs in lowlands. This is because rivers flow more slowly in low-lying areas. If the water volume increases suddenly, floods occur. iv. Coastal flooding: Flooding also occurs in coastal areas. High tides or storms cause the water level to rise. If the water level is higher than the level of the coastal lowland, flooding will occur. 2. Human Causes: i. Deforestation: Large areas of forests near/besides the rivers have been cleared. The lands are used to make room for settlement, roads and farmland. Less vegetation protects the soil; the soil is quickly lost to rivers and the sea. This raises the river bed, so the river overflows its banks easily. ii. Poor farming: Some farming practices can damage the vegetation cover, which might also become a reason for flooding. iii. Poor water management: When the dams are poorly constructed or maintained, they can easily collapse and this result in flooding. Compared to concrete dams, several earthen dams might fail. iv. Population pressure: Because of large population, everything needs more, like wood, land and food. These results in storing more water, when it can’t be maintained properly, overflow of reservoirs might take place causing floods in the downstream. 25 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed Typical Adverse Effects/Impacts: 1. Casualties: Human and livestock death due to drowning, serious injuries and outbreak of epidemics like diarrhoea, cholera, jaundice or viral infections are common problems faced in flood affected areas. Even wells, other source of drinking water get submerged resulting in acute shortage of safe drinking water during floods. Consequently often people are forced to drink the contaminated floodwater, which may cause serious diseases. 2. Structural damage: During floods mud huts and buildings built on weak foundations collapse endangering human lives and property. Damage may also be cause to roads, rail, dams, monuments, crops and cattle. Floods may uproot trees and may cause landslides and soil erosion. 3. Material loss: Household articles including eatables, electronic goods, beds, clothes, furniture get submerged in water and get spoilt all materials mounted on ground e.g. food stock, equipment, vehicles, livestock, machinery, salt pan and fishing boats can be submerged and spoilt. 4. Utilities damage: Utilities such as water supply, sewerage, communication lines, power-lines, transportation network and railways are put at risk. 5. Crop loss: Apart from the loss of human and cattle life, floods cause severe devastation of standing agricultural crops. Floods water spoils the stored food- grains or harvested crop. Floods may affect soil characteristics and may turn them infertile due to the erosion of the top soil or in coastal areas agricultural lands may turn saline due to flooding by sea water. 6. Flood control: Flood control can be achieved through various means. The floodwater can be reduced by reducing the run-off water through afforestation. Forests promote rainwater percolation in the ground, thus recharging the groundwater and reducing the run-off water. Construction of dams also reduces flood water through storage. Dams can store water, which cannot be accommodated in the river downstream may cause floods. Water can be released in a controlled manner from the dam. Desilting, deepening and increasing embankment increase the capacity of a river/channel/drain. 26 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed Precautions: Some precautionary measures are as follows: 1. Build houses away from flood prone area. 2. Keep yourself alert and updated to weather and flood forecasting information. 3. In case evacuation warnings are issued, immediately go to the shelters provided. 4. When you are moving to a shelter, move your valuable articles to safer elevated places so that they are not destroyed by flood water. 5. Store extra food, such as rice, pulses etc. for emergency. 6. Do not touch any loose electric wire to avoid electrocution. 7. Do not spread rumours or listen to them. 8. Make provision for adults and children who need special diet. 9. After the flood is over, get yourself and your family members inoculated against diseases and seek medical care for injured and sick. 10.Clear the house and dwellings of debris. 11.Report any loss to the revenue authorities. Flood Benefits: Floods (in particular more frequent or smaller floods) can also bring many benefits, such as: 1. Recharging ground water, making soil more fertile and increasing nutrients in some soils. 2. Flood waters provide much needed water resources in arid and semi‐arid regions where precipitation can be very unevenly distributed throughout the year. 3. Freshwater floods particularly play an important role in maintaining ecosystems in river corridors and are a key factor in maintaining floodplain biodiversity. 4. Flooding can spread nutrients to lakes and rivers, which can lead to increased biomass and improved fisheries for a few years. 5. Fish, such as the weather fish, make use of floods in order to reach new habitats. 6. Bird populations may also profit from the boost in food production caused by flooding. 27 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed DROUGHT Definition: Droughts may be defined as a condition that arises from too little precipitation (rain or snow) for an extended period of time for normal farming practices to be conducted. Or Drought is an event that results from lower than normal expected rainfall over a season or period. The low rainfall is insufficient to meet the needs of human beings, plants, animals and agriculture. Short fall in rain results in drying of rivers, lakes, reservoirs and drying of wells due to excessive withdrawal and poor recharge of ground water and loss of crop yield due to shortage of water are some of the main indicators of drought. Introduction:  68% of the net area sown in the country is prone to drought.  Out of this 33% is chronically drought prone, receiving rainfall less than 750mm per annum.  35% drought prone that receive rainfall between 750-1125 mm per annum. Types/Classification: Droughts can be categorized into the following types: 1. Meteorological Drought: It occurs when the average rainfall and snowfall is below average for an extended period of time, thereby causing a natural shortage of available water. 28 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed 2. Agricultural Drought: It occurs when the soil moisture is not sufficient to support the production of crops. 3. Hydrological Drought: This type of drought occurs when the water levels in aquifers, lakes and reservoirs, fall below the average levels. This can occur even during average or above average precipitation, when water consumption by humans is more, thus lowering the water reserves. Distributional Pattern: Causes: Drought occurs due to shortage of rainfall. As per Meteorological Department if rainfall is deficient by more than 10% of the annual average rainfall, the condition is said to be that of drought. The severity of drought is determined by the extent of deviation of rainfall from the average. In the recent past frequency of periods of drought have increasing due to deforestation and environmental degradation. 29 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed Effects/Impacts: 1. Economic impacts: It includes the monetary effects of drought to people. Following are some of the examples: i. Droughts destroy the growth of crops, with lower yields and crops are of poor quality. In order to provide sufficient water to crops, farmers have to spend more money to irrigate their fields. ii. The livestock of ranches may be lost. More money may have to be spent to feed and water the livestock. iii. Fishes and other aquatic organisms are lost due to drought. iv. The recreation and tourism industry incurs loss. v. The income from timber production may be lost owing to reduced timber production due to wild fires, impaired productivity of forest land and loss of young trees. vi. Businesses that process various food stuffs may lose business due to loss of crops by drought. vii. Since the hydropower will be in short supply, the power generating companies will have to spend more to provide alternative sources of power to their customers. viii. Water companies will have to spend more for new or supplemental water resource development. ix. The transportation industries suffer loss due to impaired navigability of barrages, and ships in streams, rivers and canals owing to decreased water levels. x. Shortage in food production and disrupted food supply causes increase in the import of food at higher costs. So, there is inflation in food prices. 2. Environmental impact: It includes loss to the environment by way of forest fires, erosion of soil, damage to all living forms and their habitat, decline in the water and the air quality. Some of the examples are as under: i. Due to lack of food and drinking water, due to loss of wet lands and vegetation there is greater mortality of fish and wildlife habitat. ii. Shortage of food and water leads to diseases in animals. iii. The wildlife may leave the drought stricken areas and migrate to other places. iv. The endangered species are at an increased stress. v. The water levels in the reservoirs, ponds and lakes decrease. The wetland also decreases. 30 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed vi. Drought causes the soil to dry up and become prone to erosion by wind, resulting in reduced soil quality. This leads to loss of biological productivity of the landscape. vii. Loss of biodiversity and extinction of species. 3. Social impacts: It involves public safety and health, disputes arising due to water shortage and lifestyle changes. Some of the examples in this category are: i. The revenue loss caused by drought may cause mental and physical stress on people. ii. The heat stress, mental stress and physical stress may contribute to loss of human life and suicidal tendencies. iii. Reduction in recreational activities. iv. People migrate to other places. v. The reduction in nutrition due to inflation, causes malnutrition and famine. vi. A general increase in poverty leads to changes in lifestyle and quality of life. Drought Control Measures: A drought-like situation can be avoided by the following ways: 1. Rain water harvesting: This is one of the most important and economical tool of water conservation, used for collecting and storing the rain water from roof tops and land surface to provide water for agriculture, industries and domestic use. 2. Crop Rotation: Rotation of perennial crops and leguminous plants alternating with cash crops controls soil erosion and helps the formation of better quality soil. 3. Channelizing the rivers: By building canals in drought prone areas is an efficient way to combat the effects of drought. 4. Cloud seeding: It is an artificial technique to stimulate the precipitation process and form rain. The method involves sprinkling silver iodide aerosols into the upper part of clouds. The water droplets in the clouds attach to silver iodide and freeze. The ice crystals stick together and fall as snow. 5. Desalination of sea water: Desalination plants are set up to covert sea water and contaminated water to drinking water. Desalinated water is 31 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed used mostly in the Middle East, North Africa, California and parts of Florida in the US. 6. Risk mitigation efforts by the Government: These include Drought Prone Area Program (DPAP), Desert Development Program (DDP), National Watershed Development Project for Rain-fed areas (NWDPRA), Watershed Development Program for Shifting Cultivation (WDPSC), Integrated Water Development Project (IWDP), Integrated Afforestation and Economic Development Project Scheme (IAEPS). CYCLONES Definition: Cyclone is a region of low atmospheric pressure surrounded by high atmospheric pressure resulting in swirling atmospheric disturbance accompanied by powerful winds blowing in anticlockwise direction in the Northern Hemisphere and in the clockwise direction in the Southern Hemisphere. They occur mainly in the tropical and temperate regions of the world. Or Cyclones are violent storms, often of vast extent, characterised by strong and high winds rotating about a calm center of low atmospheric pressure. This center moves onwards, often with velocity of around 50 km/h. Cyclones strike suddenly though it takes time for them to build up. Cyclone is generally followed by heavy rains causing floods. Satellite tracking can predict on possible affected areas and inhabitants fore-warned can be made for warning. Warning and evacuation is done along the projected path. 32 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed Introduction:  Long coastline of 8000 kms.  Pre-monsoon (May-June) and post-monsoon (Sept-Oct) cyclones.  Coastal districts of Orissa, Andhra Pradesh and Gujrat most prone to cyclone.  Most casualties caused by coastal inundation due to tidal waves, storm surges and torrential rains.  Cyclones are known by different names in different parts of the world: Typhoons in the Northwest Pacific Ocean west of the dateline. Hurricanes in the North Atlantic Ocean, the Northeast Pacific Ocean east of the dateline, or the South Pacific Ocean. Tropical cyclones the Southwest Pacific Ocean and Southeast Indian Ocean. Severe cyclonic storm (the North Indian Ocean). Tropical cyclone (the Southwest Indian Ocean). Willie‐Willie in Australia. Tornado in South America Types/Classification: The term 'cyclone' actually refers to several different types of storms. They occur in different places, and some occur over land while others occur over water. What they all have in common is that they are spinning storms rotating around that low ‐pressure center. 1. Tropical cyclones: Tropical cyclones are what most people are familiar with because these are cyclones that occur over tropical ocean regions. Hurricanes and typhoons are actually types of tropical cyclones, but they have different names so that it's clear where that storm is occurring. Hurricanes are found in the Atlantic and Northeast Pacific, typhoons are found in the Northwest Pacific. If you hear 'tropical cyclone,' you should assume that it's occurring in the South Pacific or Indian Ocean, but for this lesson, we'll use it refer to all types of tropical ocean cyclones. We can also further describe tropical cyclones based on their wind speeds. They are called category 1, 2, 3, 4 or 5, increasing with intensity and wind speed as the number increases. A category 1 cyclone is the weakest, with wind speeds of 74‐95 mph. A category 5 cyclone, on the other hand, is extremely dangerous 33 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed and has the potential for major damage. Category 5 cyclones have wind speeds of 155 mph and above! 2. Polar cyclones: Polar cyclones are cyclones that occur in polar regions like Greenland, Siberia and Antarctica. Unlike tropical cyclones, polar cyclones are usually stronger in winter months. As you can see, these storms really do prefer the colder weather! They also occur in areas that aren't very populated, so any damage they do is usually pretty minimal. 3. Mesocyclone: Mesocyclone is when part of a thunderstorm cloud starts to spin, which may eventually lead to a tornado. 'Meso' means 'middle', so you can think of this as the mid ‐point between one type of storm and the other. Tornadoes all come from thunderstorm clouds, but not all thunderstorm clouds make tornadoes. In order for a tornado to occur, part of that cloud has to spin, and though you can't really see this happening, this is the intermediate, or 'meso' step from regular cloud to dangerous spinning cloud running along the ground. General Characteristics: Cyclones in India are moderate in nature. Some of the general characteristics of a cyclone are: 1. Strong winds. 2. Exceptional rain. 3. Storm surge. Cyclones are generally accompanied by strong winds which cause a lot of destruction. In some cases it is accompanied by heavy downpour and also the rise in the sea which intrudes inland there by causing floods. Development of a Cyclone: The development of a cyclone covers three stages namely: 1. Formation and initial development state: Four atmospheric/oceanic conditions are necessary for the formation of a cyclone namely: i. A warm sea temperature in excess of 26 degree centigrade, to a depth of 60 meters, which provides abundant water vapour in the air by evaporation. 34 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed ii. High relative humidity (degree to which the air is saturated by to a height of about 7000 meters, facilitates condensation of water vapor into droplets and clouds, releases heat energy and induces drop in pressure). iii. Atmospheric instability (an above average decrease of temperature with altitude) encourages considerable vertical cumulus cloud convection when condensation of rising air occurs. iv. A location of at least 4‐5 latitude degrees from the Equator allow the influence of the force due to the earth’s rotation (Coriolis force) to take effect in inducing cyclonic wind circulation around low pressure centers. 2. Fully matured: The main feature of a fully mature tropical cyclone is a spiral pattern of highly turbulent giant cumulus thundercloud bands. These bands spiral inwards and form a dense highly active central cloud core which raps around a relatively calm zone. This is called the “eye” of a cyclone. The eye looks like a black hole or a dot surrounded by thick clouds. The outer circumference of the thick cloud is called the ‘eye wall’. 3. Weakening or decay: A tropical cyclone begins to weaken as soon as its source of warm moist air is abruptly cut off. This is possible when the cyclone hits the land, on the cyclone moves to a higher altitude or when there is the interference of another low pressure. Depending on their track on the warm tropical sea and proximity to land a cyclone may last for less than 24 hours to more than 3 weeks. On an average the life cycle of a cyclone (a cyclone to complete these three stages mentioned above) takes six days. The longest cyclone is typhoon John which lasted for 31 days (August to September, 1994 in the north east and north west pacific basins). Distributional Pattern: The map of India shows the areas that are generally affected by strong winds/ cyclones. 35 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed Some of the major cyclones that have affected the country in the past are as mentioned in table below: 36 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed Elements at Risk: Strong winds, torrential rains and flooding cause a huge loss to life and property. The 1999 Super Cyclone of Orissa killed more than 10,000 precious lives with women and children greatly affected. Apart from loss to life there is a huge loss to infrastructures like houses built of mud, older buildings with weak walls, bridges, settlements in low lying areas. Effects of Cyclones and Hurricanes: 1. Tropical cyclones cause heavy rainfall and landslides. 2. They cause a lot of harm to towns and villages, causing severe damage to kuccha houses. Coastal businesses like shipyards and oil wells are destroyed. 3. They harm the ecosystem of the surrounding region. 4. Civic facilities are disturbed. 5. Agricultural land is severely affected, especially in terms of water supply and soil erosion. 6. It causes harm to human, plant and animal life. 7. Communication systems are badly affected due to cyclones. Possible Risk Reduction Measures: 1. Coastal belt plantation: Green belt plantation along the coastal line in a scientific interweaving pattern can reduce the effect of the hazard. Providing a cover through green belt sustains less damage. Forests act as a wide buffer zone against strong winds and flash floods. Without the forest the cyclone travel freely inland. The lack of protective forest cover allows water to inundate large areas and cause destruction. With the loss of the forest cover each consecutive cyclone can penetrate further inland. 2. Hazard mapping: Meteorological records of the wind speed and the directions give the probability of the winds in the region. Cyclones can be predicted several days in advance. The onset is extensive and often very destructive. Past records and paths can give the pattern of occurrence for particular wind speeds. A hazard map will illustrate the areas vulnerable to cyclone in any given year. It will be useful to estimate the severity of the cyclone and various damage intensities in the region. The map is prepared with data inputs of past climatological records, history of wind speed, frequency of flooding etc. 37 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed 3. Land use control: Designed so that least critical activities are placed in vulnerable areas. Location of settlements in the flood plains is at utmost risk. Siting of key facilities must be marked in the land use. Policies should be in place to regulate land use and building codes should be enforced. 4. Engineered structures: Structures need to be built to withstand wind forces. Good site selection is also important. Majority of the buildings in coastal areas are built with locally available materials and have no engineering inputs. Good construction practice should be adopted such as: i. Cyclonic wind storms inundate the coastal areas. It is advised to construct on stilts or on earth mound. ii. Houses can be strengthened to resist wind and flood damage. All elements holding the structures need to be properly anchored to resist the uplift or flying off of the objects. For example, avoid large overhangs of roofs, and the projections should be tied down. iii. A row of planted trees will act as a shield. It reduces the energy. iv. Buildings should be wind and water resistant. v. Buildings storing food supplies must be protected against the winds and water. vi. Protect river embankments. vii. Communication lines should be installed underground. viii. Provide strong halls for community shelter in vulnerable locations. 38 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed 5. Flood management: Torrential rains strong wind and storm range leads to flooding in the cyclone affected areas. There are possibilities of landslides too. Flood mitigation measures could be incorporated (see section on floods for additional information). 6. Improving vegetation cover: The roots of the plants and trees keep the soil intact and prevent erosion and slow runoff to prevent or lessen flooding. The use of tree planted in rows will act as a windbreak. Coastal shelterbelt plantations can be developed to break severe wind speeds. It minimizes devastating effects. The Orissa calamity has also highlighted the need for urgent measures like shelterbelt plantation along cyclone‐prone coastal areas. Species chosen for this purpose should not only be able to withstand the impact of strong cyclonic winds, but also check soil erosion. VOLCANOES Definition & Introduction: Volcanoes are openings in the earth's crust created when molten material under the crust is propelled upward though the surface. The magma chamber collects the magma that is expelled to the surface in an eruption. A volcanic event could be: 1. Destructive, with voluminous lava flows or explosive activity. This usually occurs when magma is sticky and contains a lot of gas. Hot debris particles called pyroclastic are expelled during violent explosions. Heavier pieces land near the crater and lighter pieces can be carried by the wind for hundreds of miles. 2. Non-destructive, with little release of solids or magmatic liquid. These eruptions occur when the magma is more fluid and contains less gas. The solids or magma rocks and lava cools on its slope. Causes and Distribution of Volcanoes: Volcanoes are generally found where tectonic plates are diverging or converging. A mid-oceanic ridge, for example the Mid-Atlantic Ridge, has examples of volcanoes caused by divergent tectonic plates pulling apart; the Pacific Ring of Fire has examples of volcanoes caused by convergent tectonic plates coming together. By contrast, volcanoes are usually not created where two tectonic plates slide past one another. Volcanoes can also form where there 39 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed is stretching and thinning of the Earth's crust in the interiors of plates, e.g., in the East African Rift, the Wells Gray-Clearwater volcanic field and the Rio Grande Rift in North America. This type of volcanism falls under the umbrella of "Plate hypothesis" volcanism. Volcanism away from plate boundaries has also been explained as mantle plumes. These so-called "hotspots", for example Hawaii, are postulated to arise from upwelling diapirs with magma from the core–mantle boundary, 3,000 km deep in the Earth. Environmental Impacts of Volcanic Eruptions: Volcanic eruptions can be extremely damaging to the environment, particularly because of a number of toxic gases possibly present in pyroclastic material. It typically consists mainly of water vapor, but it also contains carbon dioxide and sulphur dioxide gas. Other gases typically found in volcanic ashes are hydrogen sulphide, hydrogen chloride, hydrogen fluoride, carbon monoxide, and volatile metal chlorides. Carbon dioxide emitted from volcanoes adds to the natural greenhouse effect. Sulphur-dioxides cause environmental problems, because they are converted to sulphuric acid in the stratosphere; the main cause of acid rain. Furthermore, sulphate aerosols are formed, which reflect solar radiation and absorb heat, thereby cooling the earth. Sulphate aerosols also take part in chemical reactions, forming ozone destructive material. EARTHQUAKES Definition: It is the sudden shaking of the earth crust. The impact of an earthquake is sudden and there is hardly any warning, making it impossible to predict. Or An earthquake is a phenomenon of shaking on the surface of the earth, due to the movement along geological faults present in the earth’s lithosphere. It is usually what happens when two blocks of the earth suddenly slip past one another, or break apart from each other as a result of tension caused by prolonged energy build up. This sudden release of energy from the fault plane will generate seismic waves to travel in all directions. The seismic waves that reach the earth’s surface cause an earthquake. Or 40 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed Earthquake is a sudden release of energy accumulated in deformed rocks of earth crust causing the ground to tremble or shake. Earthquake can occur suddenly any time of the year without any warning causing severe loss of life and property (Fig). We are aware of the severe damage caused by earthquakes of Latur (1993) and Bhuj (2002). Introduction: Earthquake is one of the most destructive natural hazard. They may occur at any time of the year, day or night, with sudden impact and little warning. They can destroy buildings and infrastructure in seconds, killing or injuring the inhabitants. Earthquakes not only destroy the entire habitation but may de- stabilize the government, economy and social structure of the country. Globally, earthquakes result in a loss of about 50,000 lives every year. Earthquakes over 5.5 magnitude on the Richter scale are progressively damaging to property and human life. However, there are many other factors that influences the damage pattern. Massive earthquakes generally occur near the junction of two tectonic plates, e.g., along the Himalayan range, where the Indian plate goes below Eurasian plate. The Indian sub- continent situated on the boundaries of two continental plates is very prone to earthquakes. Some of the most intense earthquakes of the world have occurred in India. Fortunately, none of these have occurred in any of the major cities. According to latest seismic zoning map brought out by the Bureau of Indian Standard (BIS), over 65 percent of the country is prone to earthquake of intensity Modified Mercalli Intensity Scale (MSK) VII or more. India has been divided into four seismic zones according to the maximum intensity of earthquake expected (Figure below). Of these, zone V is the most 41 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed active which comprises of whole of Northeast India, the northern portion of Bihar, Uttarakhand, Himachal Pradesh, J&K, Gujarat and Andaman & Nicobar Islands. India has highly populous cities and the constructions in these cities are not earthquake resistant. Regulatory mechanisms are weak, thus any earthquake striking in one of these cities would turn into a major disaster. Six major earthquakes have struck different parts of India over a span of the last 15 years. Earthquakes come in many forms:  Felt as a shock under your feet, or  Powerful and destructive enough to flatten an entire city.  Can happen anywhere, land or sea. Terminology: 1. Focus or Hypocenter: The point on the fault where slip starts is the Focus or Hypocenter. 2. Epicenter: The point vertically above this on the surface of the Earth is the Epicenter. 3. Focal Depth: The depth of focus from the epicenter, called as Focal Depth. 4. Epicentral distance: Most of the damaging earthquakes have shallow focus with focal depths less than about 70km. Distance from epicenter to any point of interest is called epicentral distance. 42 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed Types/Classification of Earthquakes: 1. Depth of focus as basis: i. Shallow: Depth of focus lies up to 60km below the surface. ii. Intermediate: Depth of focus lies between 60-300km below the surface. iii. Deep seated: Depth of focus lies between 300-700km below the surface. 2. Magnitude as basis (See classification above in Magnitude). 3. Cause of origin as basis: i. Tectonic earthquakes: Caused due to relative displacements of blocks of the crust of the earth along the rupture planes. ii. Non-tectonic earthquake: Caused due to volcanic eruptions, atomic explosions landslides and subsidence. Earthquake Hazards Zoning of India: The major reason for the high frequency and intensity of the earthquakes is that the Indian plate is driving into Asia at a rate of approximately 47 mm/year. Geographical statistics of India show that almost 54% of the land is vulnerable to earthquakes. A World Bank & United Nations report shows estimates that around 200 million city dwellers in India will be exposed to storms and earthquakes by 2050. The latest version of seismic zoning map of India given in the earthquake resistant design code of India [IS 1893 (Part 1) 2002] assigns four levels of seismicity for India in terms of zone factors. In other words, the earthquake zoning map of India divides India into 4 seismic zones (Zone 2, 3, 4 and 5) unlike its previous version which consisted of five or six zones for the country. According to the present zoning map, Zone 5 expects the highest level of seismicity whereas Zone 2 is associated with the lowest level of seismicity. The latest seismic zoning map can be accessed from The India Meteorological Department website. Each zone indicates the effects of an earthquake at a particular place based on the observations of the affected areas and can also be described using a descriptive scale like Modified Mercalli intensity scale… Zone 5: Covers the areas with the highest risks zone that suffers earthquakes of intensity IX or greater. The IS code assigns zone factor of 0.36 for Zone 5. Structural designers use this factor for earthquake resistant design of structures in Zone 5. It is referred to as the Very High Damage Risk Zone. The state of 43 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed Kashmir, the western and central Himalayas, the North-East Indian region and the Rann of Kutch falls in this zone. Generally, the areas having trap or basaltic rock are prone to earthquakes. Zone 4: This zone is called the High Damage Risk Zone and covers areas liable to intensity VIII or higher. The IS code assigns zone factor of 0.24 for Zone 4. The Indo-Gangetic basin and the capital of the country (Delhi), Jammu and Kashmir fall in Zone 4. In Maharashtra, Patanarea (Koyananager) also comes under zone 4. Zone 3: The Andaman and Nicobar Islands, parts of Kashmir, Western Himalayas fall under this zone. This zone is classified as Moderate Damage Risk Zone which is liable to intensity VII. The IS code assigns zone factor of 0.16 for Zone 3. Zone 2: This region is liable to intensity VI or less and is classified as the Low Damage Risk Zone. The IS code assigns zone factor of 0.10 (maximum horizontal acceleration that can be experienced by a structure in this zone is 10% of gravitational acceleration) for Zone 2. The entire Himalayan Region is considered to be vulnerable to high intensity earthquakes of a magnitude exceeding 8.0 on the Richter scale, and in a 44 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed relatively short span of about 50 years, four such major earthquakes have occurred in the region. The Circulations inside Earth:  Convection currents develop in the viscous Mantle, because of prevailing high temperature and pressure gradients between the Crust and the Core, like the convective flow of water when heated in a beaker.  These convection currents result in a circulation of the earth’s mass; hot molten lava comes out and the cold rock mass goes into the Earth. The mass absorbed eventually melts under high temperature and pressure and becomes a part of the Mantle.  Many such local circulations are taking place at different regions underneath the Earth’s surface, leading to different portions of the Earth undergoing different directions of movements along the surface. Tectonic Plates/Plate Tectonics:  German scientist Alfred Wegener, in 1915 proposed that, 200 million years ago the earth had only one continent called Pangaea.  Pangaea broke into pieces that slowly drifted into the present configuration of continents.  The convective flows of Mantle material cause the Crust and some portion of the Mantle, to slide on the hot molten outer core.  This sliding of Earth’s mass takes place in pieces called Tectonic Plates.  The surface of the Earth consists of seven major tectonic plates and many smaller ones. 45 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed These plates move in different directions and at different speeds from those of the neighbouring ones. 1. Convergent Boundaries: Sometimes, the plate in the front is slower; then, the plate behind it comes and collides (and mountains are formed). 2. Divergent Boundaries: Sometimes two plates move away from one another (and rifts are created). 3. Transform Boundaries: Two plates move side-by-side, along the same direction or in opposite directions. The convergent boundary has a peculiarity (like at the Himalayas) that sometimes neither of the colliding plates wants to sink. 46 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed Elastic Rebound Theory:  Tectonic plates are made of elastic but brittle rocky material.  Hence, elastic strain energy is stored in them during the relative deformations that occur due to the gigantic tectonic plate actions taking place in the Earth.  When the rocky material along the interface of the plates in the Earth’s Crust reaches its strength, it fractures and a sudden movement takes place there.  The interface between the plates where the movement has taken place (called the fault) suddenly slips and releases the large elastic strain energy stored in the rocks at the interface.  The sudden slip at the fault causes the earthquake - a violent shaking of the Earth during which large elastic strain energy released spreads out in the form of seismic waves that travel through the body and along the surface of the Earth.  After the earthquake is over, the process of strain build-up at this modified interface between the tectonic plates starts all over again.  Earth scientists know this as the Elastic Rebound Theory. Seismic Waves: Large strain energy released during an earthquake travels as seismic waves in all directions through the Earth’s layers, reflecting and refracting at each interface. These waves are of two types: 1. Body waves. 2. Surface waves. 47 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed The surface waves are restricted to near the Earth’s surface (See Fig. below). Body waves consist of Primary Waves (P-waves) and Secondary Waves (S- waves), and surface waves consist of Love waves (L-waves). Fig: Arrival of Seismic Waves at a Site 1. The P – waves (Primary waves):  P-waves are also called primary waves, push and pull waves.  These are the fastest waves in which the particles vibrate in the direction of propagation.  The velocity of P-wave is related to the rigidity of the medium and its density. 2. The S – waves (Secondary waves):  S-ways are also called secondary waves.  In these waves particles vibrate right angles to the direction of propagation of the wave. 3. The L – waves (Long waves or surface waves):  L-waves also called Long waves or surface waves.  These waves are sluggish and recorded only after the arrival of the P and S waves.  S-waves do not travel through liquids.  S-waves in association with effects of Love waves cause maximum damage to structures. 48 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed Recording of Earthquakes:  The instrument used to record the motion of seismic waves is called seismograph.  The record produced by the instrument is called Seismogram.  A seismograph is designed for recording either the horizontal or the vertical component of ground motion.  A seismograph, has three components – the sensor, the recorder and the timer. i. The Sensor: The pendulum mass, string, magnet and support. ii. The Recorder: The drum, pen and chart paper constitute the recorder. iii. The Timer: The motor that rotates the drum at constant speed forms the timer.  Pendulum type seismographs are generally used. Principle of Seismograph:  A pen attached at the tip of an oscillating simple pendulum (a mass hung by a string from a support) marks on a chart paper that is held on a drum rotating at a constant speed.  A magnet around the string provides required damping to control the amplitude of oscillations.  One such instrument is required in each of the two orthogonal horizontal directions. 49 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed  For measuring vertical oscillations, the string pendulum is replaced with a spring pendulum oscillating about a fulcrum.  Today, digital instruments using modern computer technology are more commonly used.  The digital instrument records the ground motion on the memory of the microprocessor that is in-built in the instrument. Magnitude of Earthquake:  Magnitude is a quantitative measure of the actual size of the earthquake.  Magnitude of an earthquake is a measure of its size.  Professor Charles Richter noticed that, a. At the same distance, seismograms of larger earthquakes have bigger wave amplitude than those of smaller earthquakes. 50 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed b. For a given earthquake, seismograms at farther distances have smaller wave amplitude than those at close distances.  These prompted him to propose the now commonly used magnitude scale, the Richter scale.  It is obtained from the seismograms and accounts for the dependence of waveform amplitude on epicentral distance. This scale is also called Local Magnitude scale.  Earthquakes are classified based on magnitude as Intensity of Earthquake:  Intensity is an indicator of the severity of shaking generated at a given location.  Intensity is a qualitative measure of the actual shaking at a location during an earthquake, and is assigned as Roman Capital Numerals.  There are many intensity scales. Two commonly used ones are the Modified Mercalli Intensity (MMI) Scale and the Medvedev–Sponheuer– Karnik (MSK) Scale.  Both scales are quite similar and range from I (least perceptive) to XII (most severe).  The intensity scales are based on three features of shaking: 1. Perception by people and animals. 2. Performance of buildings. 3. Changes to natural surroundings.  The distribution of intensity at different places during an earthquake is shown graphically using isoseismals, lines joining places with equal seismic intensity. 51 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed Possible Risk Reduction Measures: 1. Community preparedness: Community preparedness is vital for mitigating earthquake impact. The most effective way to save you even in a slightest shaking is 'DROP, COVER and HOLD'. 2. Planning: The Bureau of Indian Standards has published building codes and guidelines for safe construction of buildings against earthquakes. Before the buildings are constructed the building plans have to be checked by the Municipality, according to the laid down bylaws. Many existing lifeline buildings such as hospitals, schools and fire stations may not be built with 52 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed earthquake safety measures. Their earthquake safety needs to be upgraded by retrofitting techniques. 3. Public education is educating the public on causes and characteristics of an earthquake and preparedness measures. It can be created through sensitization and training programme for community, architects, engineers, builders, masons, teachers, government functionaries teachers and students. 4. Engineered structures: Buildings need to be designed and constructed as per the building by laws to withstand ground shaking. Architectural and engineering inputs need to be put together to improve building design and construction practices. The soil type needs to be analysed before construction. Building structures on soft soil should be avoided. Buildings on soft soil are more likely to get damaged even if the magnitude of the earthquake is not strong as shown in Figure below. Similar problems persist in the buildings constructed on the river banks which have alluvial soil. Mitigation of Earthquake:  National, State & Dist. Disaster Management Authorities should be established.  Large number of strong ground motion recorders should be installed.  Identification and quantification of where the hazard exists should be made.  Seismic zonation (macro and micro) should be done.  Numerical simulations should be done if there is no previous data. 53 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed  Review of building bye-laws (codes of practice) should be done, with every advancement in research.  Considering probable input forces, buildings should be analyzed, designed and constructed with utmost care.  Implementation gap should be reduced between poor and rich.  Critical information should reach the emergency response team in time, to prevent further losses.  Earthquake engineering in undergraduate engineering/architecture curricular.  Hospital preparedness and emergency health management in medical education.  Retrofitting of life-line structures (old/vulnerable).  Urban earthquake vulnerability reduction programme.  Mainstreaming mitigation in rural areas. Causes of Earthquakes: Earthquakes develop in the crust of the earth (earth’s surface, submarine levels, down to the ocean floors). The inner part of the earth contains massive energy. Some of which escapes through cracks and other volcanic activity. The energy stored causes the tectonic plates to slide, glide, knock and move around other tectonic plate. After a period of time, the built up energy and movement causes huge tension in the plates and there is a massive pressure on the fault lines. The pressure resulting from built up energy causes the fault line give way, and plates move over, against or apart from each other. Hazardous Effect/Impacts of Earthquakes: Ground shaking itself is not dangerous. However, the resulting damage to buildings and other structures and the risk of casualties from falling debris can make it extremely hazardous. The real dangers to people are being crushed in a collapsing building, drowning in a flood caused by a broken dam or levee, getting buried under a landslide, or being burned in a fire. Some of the earthquake effects that can be harmful to people are: 1. The Effect of Ground Shaking: The first main earthquake hazard (danger) is the effect of ground shaking. Buildings can be damaged by the shaking itself or by the ground beneath them settling to a different level than it was before the earthquake (subsidence). 54 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed 2. Ground Displacement: The second main earthquake hazard is ground displacement (ground movement) along a fault. If a structure (a building, road, etc.) is built across a fault, the ground displacement during an earthquake could seriously damage or rip apart that structure. 3. Flooding: The third main hazard is flooding. An earthquake can rupture (break) dams or levees along a river. The water from the river or the reservoir would then flood the area, damaging buildings and maybe sweeping away or drowning people. 4. Tsunamis and Seiches: A temporary disturbance or oscillation in the water level of a lake, esp.one caused by changes in atmospheric pressure can also cause a great deal of damage. 5. Fire: The fifth main earthquake hazard is fire. These fires can be started by broken gaslines and power lines, or tipped over wood or coal stoves. They can be a serious problem, especially if the water lines that feed the fire hydrants are broken, too. For example, after the Great San Francisco Earthquake in 1906, the city burned for three days. Most of the city was destroyed and 250,000 people were left homeless. TSUNAMI [OR] SEISMIC SEA WAVE [OR] TIDAL WAVE Definition: A tsunami is a very long‐wavelength wave of water that is generated by sudden displacement of the seafloor or disruption of any body of standing water. Tsunami are sometimes called "seismic sea waves", although they can be generated by mechanisms other than earthquakes. Tsunami have also been called "tidal waves", but this term should not be used because they are not in any way related to the tides of the Earth. Because tsunami occur suddenly, often without warning, they are extremely dangerous to coastal communities. Or Tsunami is also called seismic sea wave, or tidal wave, catastrophic ocean wave, usually caused by a submarine earthquake occurring less than 50 km (30 miles) beneath the seafloor, with a magnitude greater than 6.5 on the Richter scale. Underwater or coastal landslides or volcanic eruptions also may cause a tsunami. The term tidal wave is more frequently used for such a wave, but it is a misnomer, for the wave has no connection with the tides. 55 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed Introduction: The term Tsunami has been derived from a Japanese term Tsu meaning 'harbor' and nami meaning 'waves'. Tsunamis are popularly called tidal waves but they actually have nothing to do with the tides. These waves which often affect distant shores, originate by rapid displacement of water from the lake or the sea either by seismic activity, landslides, volcanic eruptions or large meteoroid impacts. Whatever the cause may be sea water is displaced with a violent motion and swells up, ultimately surging over land with great destructive power. The effects of a tsunami can be unnoticeable or even destructive. Physical Characteristics of Tsunami: All types of waves, including tsunami, have a wavelength, a wave height, an amplitude, a frequency or period, and a velocity. 56 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed 1. Wavelength: It is defined as the distance between two identical points on a wave (i.e. between wave crests or wave troughs). Normal ocean waves have wavelengths of about 100 meters. Tsunami have much longer wavelengths, usually measured in kilometers and up to 500 kilometers. 2. Wave height: It refers to the distance between the trough of the wave and the crest or peak of the wave. 3. Wave amplitude: It refers to the height of the wave above the still water line, usually this is equal to 1/2 the wave height. Tsunami can have variable wave height and amplitude that depends on water depth as we shall see in a moment. 4. Wave frequency or period: It is the amount of time it takes for one full wavelength to pass a stationary point. 5. Wave velocity: It is the speed of the wave. Velocities of normal ocean waves are about 90 km/hr while tsunami have velocities up to 950 km/hr (about as fast as jet airplanes), and thus move much more rapidly across ocean basins. The velocity of any wave is equal to the wavelength divided by the wave period. V = λ/P Tsunami are characterized as shallow‐water waves. These are different from the waves most of us have observed on the beach, which are caused by the wind blowing across the ocean's surface. Wind generated waves usually have period (time between two successive waves) of five to twenty seconds and a wavelength of 100 to 200 meters. A tsunami can have a period in the range of ten minutes to two hours and wavelengths greater than 500 km. How Tsunami are Generated? The geological movements that cause tsunamis are produced in three major ways. The most common of these are fault movements on the sea floor, accompanied by an earthquake. They release huge amount of energy and have the capacity to cross oceans. The degree of movement depends on how fast the earthquake occurs and how much water is displaced. Fig blow shows how an earthquake causes tsunami. 57 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed The second most common cause of the tsunami is a landslide either occurring under water or originating above the sea and then plunging into the water. The largest tsunami ever produced by a landslide was in Lituya Bay, Alaska 1958. The massive rock slide produced a wave that reached a high water mark of 50 ‐ 150 meters above the shoreline. There is an average of two destructive tsunami per year in the Pacific basin. Pacific wide tsunami is a rare phenomenon, occurring every 10‐12 years on the average. Most of these tsunamis are generated by earthquakes that cause displacement of the seafloor, but, as we shall see, tsunami can be generated by volcanic eruptions, landslides, underwater explosions, and meteorite impacts. 1. Earthquake: Earthquakes cause tsunami by causing a disturbance of the seafloor. Thus, earthquakes that occur along coastlines or anywhere beneath the oceans can generate tsunami. The size of the tsunami is usually related to the size of the earthquake, with larger tsunami generated by larger earthquakes. But the sense of displacement is also important. Tsunami are generally only formed when an earthquake causes vertical displacement of the seafloor. 58 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed 2. Volcanic Eruptions: Volcanoes that occur along coastal zones, like in Japan and island arcs throughout the world, can cause several effects that might generate a tsunami. Explosive eruptions can rapidly emplace pyroclastic flows into the water, landslides and debris avalanches produced by eruptions can rapidly move into water, and collapse of volcanoes to form calderas can suddenly displace the water. 3. Landslides: Landslides moving into oceans, bays, or lakes can also generate tsunami. Most such landslides are generated by earthquakes or volcanic eruptions. 4. Underwater Explosions: Nuclear testing by the United States in the Marshall Islands in the 1940s and 1950s generated tsunami. 5. Meteorite Impacts: While no historic examples of meteorite impacts are known to have produced a tsunami, the apparent impact of a meteorite at the end of the Cretaceous Period, about 65 million years ago near the tip of what is now the Yucatan Peninsula of Mexico, produced tsunami that left deposits all along the Gulf coast of Mexico and the United States. Mitigation of Risks and Hazards: The main damage from tsunami comes from the destructive nature of the waves themselves. Secondary effects include the debris acting as projectiles which then run into other objects, erosion that can undermine the foundations of structures built along coastlines, and fires that result from disruption of gas and electrical lines. Tertiary effects include loss of crops and water and electrical systems which can lead to famine and disease. Typical Adverse Effects/Impacts: Local tsunami events or those less than 30 minutes from the source cause the majority of damage. The force of the water can raze everything in its path. It is normally the flooding affect of the tsunami that causes major destruction to the human settlements, roads and infrastructure thereby disrupting the normal functioning of the society. Withdrawal of the tsunami causes major damage. As the waves withdraw towards the ocean they sweep out the foundations of the buildings, the beaches get destroyed and the houses carried out to sea. Damage to ports and airports may prevent importation of needed food and medical supplies. Apart from the 59 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed physical damage, there is a huge impact on the public health system. Deaths mainly occur because of drowning as water inundates homes. Many people get washed away or crushed by the giant waves and some are crushed by the debris, causes. There are very few evidences which show that tsunami flooding has caused large scale health problem. Availability of drinking water has always been a major problem in areas affected by a disaster. Sewage pipes may be damaged causing major sewage disposal problems. Open wells and other ground water may be contaminated by salt water and debris and sewage. Flooding in the locality may lead to crop loss, loss of livelihood like boats and nets, environmental degradation etc. Possible Risk Reduction Measures: While it is of course not possible to prevent a tsunami, in certain tsunami prone countries some measures have been taken to reduce the damage caused on shore. Japan has implemented an extensive programme of building tsunami walls of up to 4.5 m (13.5 ft) high in front of populated coastal areas. Other localities have built flood gates and channels to redirect the water from incoming tsunamis. However, their effectiveness has been questioned, as tsunamis are often higher than the barriers. For instance, the tsunami which hit the island of Hokkaido on July 12, 1993 created waves as much as 30m (100 ft) tall ‐ as high as a 10‐story building. The port town of Aonae on Hokkaido was completely surrounded by a tsunami wall, but the waves washed right over the wall and destroyed all the wood framed structures in the area. The wall may have succeeded in slowing down and moderating the height of the tsunami but it did not prevent major destruction and loss of life. Some other systematic measures to protect coastlines against tsunamis include: 1. Site planning and Land management: Within the broader framework of a comprehensive plan, site planning determines the location, configuration, and density of development on particular sites and is, therefore, an important tool in reducing tsunami risk.  The designation and zoning of tsunami hazard areas for such open‐space uses as agriculture, parks and recreation, or natural hazard areas is 60 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed recommended as the first land use planning strategy. This strategy is designed to keep development at a minimum in hazard areas.  In areas where it is not feasible to restrict land to open‐space uses, other land use planning measures can be used. These include strategically controlling the type of development and uses allowed in hazard areas, and avoiding high‐value and high occupancy uses to the greatest degree possible. 2. Engineering structures: Most of the habitation of the fishing community is seen in the coastal areas. The houses constructed by them are mainly of lightweight materials without any engineering inputs. Therefore there is an urgent need to educate the community about the good construction practices that they should adopt such as:  Site selection: Avoid building or living in buildings within several hundred feet of the coastline as these areas are more likely to experience damage from tsunamis.  Construct the structure on a higher ground level with respect to mean sea level.  Elevate coastal homes: Most tsunami waves are less than 3 meters in height. Elevating house will help reduce damage to property from most tsunamis.  Construction of water breakers to reduce the velocity of waves.  Use of water and corrosion resistant materials for construction.  Construction of community halls at higher locations, which can act as shelters at the time of a disaster. 3. Flood management: Flooding will result from a tsunami. Tsunami waves will flood the coastal areas. Flood mitigation measures could be incorporated. Predictability/Warning: There are two distinct types of tsunami warning: 1. International tsunami warning systems. 2. Regional warning systems. Tsunamis have occurred in all the oceans and in the Mediterranean Sea, but the great majority of them have occurred in the Pacific Ocean. Since scientists cannot exactly predict earthquakes, they also cannot exactly predict when a tsunami will be generated. 61 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed 1. International tsunami warning systems: Shortly after the Hilo Tsunami (1946), the Pacific Tsunami Warning System (PTWS) was developed with its operational center at the Pacific Tsunami Warning Center (PTWC) near Honolulu, Hawaii. The PTWC is able to alert countries several hours before the tsunami strikes. The warning includes predicted arrival time at selected coastal communities where the tsunami could travel in few hours. A tsunami watch is issued with subsequent arrival time to other geographic areas. 2. Regional warning systems: It use seismic data about nearby earthquakes to determine if there is a possible local threat of a tsunami. Such systems are capable enough to provide warnings to the general public in less than 15 minutes. In India, the Survey of India maintains a tide gauge network along the coast of India. The gauges are located in major ports as shown in the figure. The day‐to‐day maintenance of the gauge is carried with the assistance from authorities of the ports. Apart from the tide gauge, tsunami can be detected with the help of radars. The 2004 Indian Ocean tsunami, recorded data from four radars and recorded the height of tsunami waves two hours after the earthquake. It should be noted that the satellites observations of the Indian Ocean tsunami would not have been of any use in delivering warnings, as the data took five hours to process and it was 62 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed pure chance that the satellites were overhead at that time. However, in future it is possible that the space based observation might play a direct role in tsunami warning. What to do when a Tsunami warning is issued? 1. Listen to a radio, Coast Guard emergency frequency station, or other reliable source for updated emergency information. Authorities will issue a warning only if they believe there is a real threat from tsunami. 2. Follow instructions issued by local authorities. Recommended evacuation routes may be different from the one you use, or you may be advised to climb higher. 3. If you are in a tsunami risk area, do the following: i. If you hear an official tsunami warning or detect signs of a tsunami, evacuate at once. A tsunami warning is issued when authorities are certain that a tsunami threat exists, and there may be little time to get out. ii. Take your Disaster Supplies Kit. Having supplies will make you more comfortable during the evacuation. iii. Get to higher ground as far inland as possible. Officials cannot reliably predict either the height or local effects of tsunamis. Watching a tsunami from the beach or cliffs could put you in grave danger. If you can see the wave, you are too close to escape it. iv. Return home only after local officials tell you it is safe. What to do after a Tsunami? 1. Continue listening to the radio, Coast Guard emergency frequency station, or other reliable source for emergency information. 2. Help injured or trapped persons. Give first aid where appropriate. 3. Help a neighbour who may require special assistance‐infants, elderly people, and people with disabilities. 4. Use the telephone only for emergency calls. 5. Stay out of the building if waters remain around it. 6. When re‐entering buildings or homes, use extreme caution. 7. Wear sturdy shoes. 8. Use battery‐powered lanterns or flashlights when examining buildings. 9. Examine walls, floors, doors, staircases, and windows to make sure that the building is not in danger of collapsing. 63 | P a g e Disaster Preparedness & Planning Management Riyaz Mohammed 10.Inspect foundations for cracks or other damage. 11.Look for fire hazards. 12.Check for gas leaks. 13.Look for electrical system damage. 14.Check for sewage and water line damage. 15.Use tap water if local health officials advise it is safe. 16.Watch out for animals, especially poisonous snakes that may have come into buildings with the water. 17.Watch for loose plaster, drywall and ceilings that could fall. 18.Take pictures of the damage, both building and its contents, for insurance claims. 19.Open the windows and doors to help dry the building. 20.Shovel mud while it is still moist to give walls and floors an opportunity to dry. 21.Check food supplies. LANDSLIDES [OR] MASS MOVEMENT [OR] LAND SLIPS [OR] MUDSLIDES Definition & Introduction: A landslide or landslip is a geological phenomenon which includes a wide range of ground movements, such as rockfalls, deep failure of slopes and shallow debris flows, which can oc