Natural hazards
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Natural hazards

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Natural hazards Natural hazards Presentation Transcript

  • Natural Disasters
  • Natural Disasters
  • Fundamental Concepts Related To Natural Hazards Natural process have service functions. Hazards are predictable. Linkages exist between hazards and physical and biological environment. Hazards that previously produced disasters are now producing catastrophe Risks from hazards can be estimated. Adverse effects can be minimized.
  • Land movement disasters Land movement disasters are disasters that occur on land. Some land movement disasters are earthquakes, avalanches, volcanic eruptions, wildfires, landslides and many more. Water Disasters Water Disasters are disasters that occur in water such as oceans, rivers, lakes, etc.Some types of water disasters are droughts, tsunamis, tidal waves, floods, and many more. Weather Disasters Weather disasters are disasters that occur with the weather and causes changes in the weather. Some types of weather disasters are tornadoes, cyclones, hurricanes, blizzards, lighting, thunderstorms.
  • Earthquakes • The shaking or trembling caused by the sudden release of energy • Usually associated with faulting or breaking of rocks • Continuing adjustment of position results in aftershocks
  • Global Earthquake LocationsGlobal Earthquake Locations
  • Volcanic Eruptions A volcano is an opening in theA volcano is an opening in the planets surface which letsplanets surface which lets hot, rocks, ash, molten lava,hot, rocks, ash, molten lava, and gases onto the surfaceand gases onto the surface from inside the planet.from inside the planet. Volcanic activity involving theVolcanic activity involving the extrusion of rock intends toextrusion of rock intends to form mountains over aform mountains over a period of time.period of time. Volcanoes are found whereVolcanoes are found where tectonic plates are eithertectonic plates are either diverging or convergingdiverging or converging.. • A volcanic eruption is when aA volcanic eruption is when a volcano erupts and lets out lava,volcano erupts and lets out lava, rocks, ash, and many more things.rocks, ash, and many more things. • These things that are let outThese things that are let out during a volcanic eruption areduring a volcanic eruption are from the inside of the planet.from the inside of the planet. • Volcanoes can form where thereVolcanoes can form where there is stretching and thinning of theis stretching and thinning of the planet’s crust or surface.planet’s crust or surface.
  • Wildfires • Wildfires are common inWildfires are common in different parts of thedifferent parts of the world and they happen inworld and they happen in cycles.cycles. • They are useful in theThey are useful in the wilderness sometimeswilderness sometimes because the effects of thebecause the effects of the fires help some speciesfires help some species with growth andwith growth and reproduction.reproduction. • Nine out of ten wildfiresNine out of ten wildfires are caused by humansare caused by humans interaction.interaction. Wildfires are when fire isWildfires are when fire is spreading quickly. A wildfire isspreading quickly. A wildfire is a fierce fire that spreadsa fierce fire that spreads rapidly and mostly in an arearapidly and mostly in an area of wildernessof wilderness A wildfire is any uncontrolledA wildfire is any uncontrolled fire which occurs infire which occurs in wilderness, wild lands, orwilderness, wild lands, or bushes.bushes. Another word to say wildfire canAnother word to say wildfire can be bushfire, hill fire, and manybe bushfire, hill fire, and many more things can be the samemore things can be the same meaning as a wildfire.meaning as a wildfire. Wildfires means somethingWildfires means something furious or destructive.furious or destructive.
  • Tsunami is a Japanese word meaning ‘harbor wave’. It isTsunami is a Japanese word meaning ‘harbor wave’. It is constituted with two syllables, Japanese language meaningconstituted with two syllables, Japanese language meaning harbour ("tsu",harbour ("tsu", 津津 ) and) and wavewave ("nami",("nami", 波波 ).). Tsunami is a wave train or series of waves generated, byTsunami is a wave train or series of waves generated, by impulsive disturbance that vertically displaces the water column,impulsive disturbance that vertically displaces the water column, in water body. Earthquake, landslides, volcanic eruption,in water body. Earthquake, landslides, volcanic eruption, explosion and even the impact of cosmic bodies like meteoritesexplosion and even the impact of cosmic bodies like meteorites commonly generate tsunami. Tsunami savagely attacks coastlinescommonly generate tsunami. Tsunami savagely attacks coastlines causing devastating property damage and loss of lives.causing devastating property damage and loss of lives.
  • Tsunami can be generated when the see floor abruptly deforms and verticallyTsunami can be generated when the see floor abruptly deforms and vertically displaces the overlying water.displaces the overlying water. Tectonic earthquakes are a particular kind of earthquake that are associatedTectonic earthquakes are a particular kind of earthquake that are associated with the earth’s crustal deformation, when these earthquakes occur beneathwith the earth’s crustal deformation, when these earthquakes occur beneath the see, the water above the deformed area is displayed from its equilibriumthe see, the water above the deformed area is displayed from its equilibrium position.position. Waves are formed as the displaced water mass, which acts under the influenceWaves are formed as the displaced water mass, which acts under the influence of gravity, attempts to regain its equilibriumof gravity, attempts to regain its equilibrium
  • Droughts • Droughts are long period of extremely dry weather when there is not enough rain for the successful growing of crops or the replenishment of water supplies.
  • Floods • Floods are water covering previously dry area. • A flood is a very large amount of water that has overflowed from a source such as a river, lake, and ocean. • They can also have overflowed a broken pipe onto a previously dry area. • The damages after a flood is harsh because everything or parts of things will be under water and the effects of a flood can kill many people.
  • Kinds Of Floods Flooding can also be divided into different categories according to their location: Coastal Floods Coastal Floods usually occur along coastal areas. When there are hurricanes and tropical storms which will produce heavy rains, or giant tidal waves created by volcanoes or earthquakes, ocean water may be driven onto the coastal areas and cause coastal floods. River Floods This is the most common type of flooding. When the actual amount of river flow is larger than the amount that the channel can hold, river will overflow its banks and flood the areas alongside the river. And this may cause by reasons like snow melt or heavy spring rain. Urban Floods In most of the urban area, roads are usually paved. With heavy rain, the large amount of rain water cannot be absorbed into the ground and leads to urban floods.  
  • Benefits There are many disruptive effects of flooding on human settlements and economic activities. However, floods (in particular the more frequent/smaller floods) can bring many benefits, such as recharging ground water, making soil more fertile and providing nutrients in which it is deficient. Flood waters provide much needed water resources in particular in arid and semi-arid regions where precipitation events can be very unevenly distributed throughout the year. Freshwater floods in particular play an important role in maintaining ecosystems in river corridors and are a key factor in maintaining floodplain biodiversity
  • Urban Areas Rural Areas Massive amounts of erosion can be accomplished by flood waters. Such erosion can undermine bridge structures, levees, and buildings causing their collapse. Flooding of farmland usually results in crop loss.  Livestock, pets, and other animals are often carried away and drown. Water entering human built structures cause water damage. Even with minor flooding of homes, furniture is ruined, floors and walls are damaged, and anything that comes in contact with the water is likely to be damaged or lost.   Flooding of automobiles usually results in damage that cannot easily be repaired. Transportation systems may be disrupted, resulting in shortages of food and clean-up supplies. Food grains stored at home or in go-downs get wet and start rotting. In under developed countries food shortages often lead to starvation Gas and electrical service may be disrupted. Water supply pipes/ system get damaged and wells get inundated creating shortage of drinking water. The affected communities living in temporary shelters/ resettlements have limited or no access to safe drinking water, food etc. In addition, prevailing unhygienic sanitary conditions make it conducive for spread of food and water­borne diseases.
  • Hurricanes • Hurricanes are several tropical storms that can form in the Atlantic Ocean, Caribbean Sea, Gulf of Mexico, and in the Pacific Ocean. • Hurricanes gather heat and energy through contact with warm ocean waters. • Hurricanes are named so people can spot and identify them while they move across the ocean. • Hurricanes that occur at the seas, and oceans cause large waves, heavy rain, and high winds. These things can cause destruction to international shipping and may cause many shipwrecks. • Tropical cyclones is another name for hurricanes when it is at a certain level or at a certain size. • Some hurricanes that have occurred are the Bombay Hurricane in 1882 in India, and Hurricane Katrina which happened in the United States.
  • Lighting storms and Thunderstorms • Lighting storms and thunderstorms are basically the same thing. • They both contain flashes of lighting striking an area and the effects of the lighting causes thunder. • Sometimes during these storms, it also rains, snows or hails in certain cases. • A lighting is caused when a electrical charge is contained in a cloud and then releases it on the earth’s surface. The temperature of a lighting bolts is extremely hot.
  • Tornedoes • Tornadoes can happen when there is a thunderstorm. The color of tornadoes ranges from shades of gray, shades of brown, and white. Some times they are not that visible to see. • A tornado is a dangerous rotating column of air which is connected to the surface of the earth and a clod. It destroys anything it touches in its path. • Tornadoes are extremely destructive funnel-shaped rotating column of air that passes in a narrow path over land. • Tornadoes can come in many sizes and shapes. The usual shape of a tornado is a funnel, which is seeable and is narrow end touches the earth’s surface.
  • Cyclones • A cyclone is a large-scale storm system with heavy rain and winds that rotate counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere around and toward a low pressure center. • Cyclones have also been seen on other planets other then the Earth, such as Mars, and Neptune. • Some deadly cyclones that happened before are the Bhola cyclone in Bangladesh in 1970, the India cyclone in India in 1839, the Calcutta cyclone in India in 1737, and the Bangladesh cyclone in Bangladesh in 1991.
  • DISASTER MANGEMENT Hazard Management Activities a. Disaster Mitigation b. Natural Hazard Prediction c. Emergency Preparedness d. Disaster Rescue and Relief e. Post-Disaster Rehabilitation and Reconstruction f. Education and Training Activities
  • Disaster Mitigation An accurate and timely prediction of a hazardous event can save human lives but does little to reduce economic losses or social disruption which can only be accomplished by measures taken longer in advance. Mitigation of disasters usually entails reducing the vulnerability of the elements at risk, modifying the hazard-proneness of the site, or changing its function.
  • Natural Hazard Prediction The prediction of a natural event can be done by scientific investigation into its causes and ensures establishing the probability of the next occurrence in terms of time, place, and range of severity. Increasingly sophisticated monitoring stations, both manned and remote, collect information of potentially hazardous events for more accurate prediction. Some hazards, such as hurricanes and floods, can be forecast with high accuracy, whereas it’s very difficult to forecast earthquakes or volcanoes or landslides.
  • Emergency Preparedness Emergency preparedness is aimed at minimizing the loss of life and property during a natural event. Preparedness includes actions taken in anticipation of the event and special activities both during and immediately after the event. Two levels of preparedness Public safety information Hazard awareness planning
  • Disaster Rescue and Relief After a natural calamity, local residents usually undertake the first relief activities. However, their efforts must usually be complemented with those of national or regional authorities. The main activities of post-disaster relief include the preparation of lifelines or critical facilities for emergency response, training, disaster rehearsals, and the identification and allocation of local and external resources.
  • Post-Disaster Rehabilitation and Reconstruction Post-disaster rehabilitation is carried out to restore the normal functions of public services, business, and commerce, to repair housing and other structures, and to return production facilities to operation.
  • Education and Training Activities Education and training, both formal and informal, prepare people at all levels to participate in hazard management. Universities, research centers, and international development assistance agencies play the leading formal role in preparing individuals to face natural hazards. These activities are also carried out by operational entities such as ministries of agriculture, transportation, public works, and defense.
  • THANKS