DM L-2 disiater management about the earth.pptx

Disiater Management

1. Disaster Management Unit-1 Causes, Effects and Mitigation measure of different types of Disaster Date: 18/02/22

2. Disaster Management Each hazard has its own characteristics. Understand the significance and implications of various types of hazards. understanding about the nature, causes and effects of each hazard type and the mitigation measures that need to be taken up.

3. Earthquake Earthquake is one of the most destructive natural hazard. Earthquakes not only destroy the entire habitation but may de-stabilize the government, economy and social structure of the country.

4. Cause of Earthquake The earth’s crust is a rocky layer of varying thickness ranging from a depth of about 10 km under the sea to 65 km. under the continents. ‘ theory of plate tectonics’. These stresses can be classified according to the type of movement along the plate’s boundaries: a)  pulling away from each other, b)  pushing against one another c)  sliding sideways relative to each other.

5. Different Types of movements of plates Epicenter Epicentral Distance Focal Depth Focus Fault Rupture

6. Measuring Earthquake Earthquake magnitude or amount of energy released is determined by the use of a seismograph’ which is an instrument that continuously records ground vibration. The scale was developed by a seismologist named Charles Richter. The second type of scale, the earthquake intensity scale measures the effects of an earthquake where it occurs. The most widely used scale of this type was developed in 1902 by Mercalli an Italian seismologist.

7. Distribution pattern of Earthquakes in India India falls quite prominently on the 'Alpine - Himalayan Belt'. This belt is the line along which the Indian plate meets the Eurasian plate. Year Location Magnitude of 6+ 1950 Arunachal Pradesh - China Border 8.5 1956 Anjar, Gujarat 7.0 1967 Koyna, Maharashtra 6.5 1975 Kinnaur, Himachal Pradesh 6.2 1988 Manipur - Myanmar Boarder 6.6 1988 Bihar - Nepal Border 6.4 1991 Uttarkashi - Uttar Pradesh Hills 6.0 1993 Latur - Maharashtra 6.3 1997 Jabalpur, Madhya Pradesh 6.0 1999 Chamoli, Uttar Pradesh 6.8 2001 Bhuj, Gujarat 6.9 2005 Muzaffarabad (Pakistan) Impact in Jammu & Kashmir 7.4 list of significant Earthquakes in India

8. Possible Risk Reduction Measure Community preparedness Planning Public education Engineered structures

9. Possible Risk Reduction Measure

10. Tsunami The term Tsunami has been derived from a Japanese term Tsu meaning ' harbor ' and nami meaning 'waves'. 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.

11. Causes of a Tsunami 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 earth-quake.

12. Causes of a Tsunami 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. The third major cause of tsunami is volcanic activity. The flank of a volcano located near the shore or under water may be uplifted or depressed similar to the action of a fault, or, the volcano may actually explode.

13. General Characteristic Tsunami differs from ordinary ocean waves, which are produced by wind blowing over water. Compared to normal wave speed of 100 kmper hour, tsunami in the deep water of the ocean may travel the speed of a jet airplane - 800 km per hour. Tsunami normally causes flooding as a huge wall of water enters the main land.

14. Predictability There are two distinct types of tsunami warning: a)  International tsunami warning systems and b)  Regional warning systems.

15. Distribution pattern of Tsunami in India The whole of the Indian coastal belt is prone to Tsunami. Date Location Impact 1524 Near Dabhol, Maharashtra Sufficient data not available 02 April 1762 Arakan Coast, Myanmar Sufficient data not available 16 June 1819 Rann of Kachchh, Gujarat Sufficient data not available 31 October 1847 Great Nicobar Island Sufficient data not available 31 December 1881 An earthquake of 7.9 in the Richter scale in Car Nicobar Island Entire east coast of India and Andaman & Nicobar Islands; 1m tsunamis were recorded at Chennai. 26 August 1883 Explosion of the Krakatoa volcano in Indonesian. East coast of India was affected; 2m tsunamis were recorded at Chennai. 26 June 1941 An 8.1 Richter scale earthquake in the Andaman archipelago. East coast of India was affected but no estimates of height of the tsunami is available 27 November 1945 An 8.5 Richter scale earthquake at a distance of about 100km south of Karachi West coast of India from north to Karwar was affected; 12m tsunami was felt at Kandla. 26 December 2004 Banda Aceh, Indonesia; Tamil Nadu, Kerala, Andhra Pradesh, Andaman and Nicobar Islands, India; Sri Lanka; Thailand; Malaysia; Kenya; Tanzania The East cost of India was affected. The waves measured around 10 m high killing more than 10,000 precious lives. History of Tsunami’s in India

16. Possible Risk Reduction Measure 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. Tsunami walls in populated coastal areas of Japan Japan has implemented an extensive programme of building tsunami walls of up to 4.5m (13.5 ft) high in front of populated coastal areas.

17. Possible Risk Reduction Measure Site Planning and Land Management - The designation and zoning of tsunami hazard areas for such open-space uses as agriculture, parks and recreation, or natural hazard areas is recommended as the first land use planning strategy. Engineering Structure Site Selection; Construct the structure on a higher ground level with respect to mean sea level; Elevate coastal homes; Construction of water breakers to reduce the velocity of waves.

18. Cyclone 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. General Characteristic: Strong Winds; Exceptional rain; Storm Surge

19. Stages of Cyclone Development Formation and Initial Development State Fully Matured Weakening or Decay Cyclone Formation 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.

20. Indian Cyclones Cyclones vary in frequency in various parts of the world. The 7516.6 km long Indian coastline is the earth’s most cyclone battered stretch of the world. The states which are generally affected in the east coast are West-Bengal, Orissa, Andhra Pradesh; Tamil Nadu and on the west coast Gujarat, Maharashtra, Goa, Karnataka and Kerala.

21. Distributional Pattern Sl No Year Area Death toll 1 1971 Eastern Coast 9658 2 1972 Andhra Pradesh and Orissa 100 3 1977 Chennai, kerala & Andhra Pradesh 14,204 4 1979 Andhra Pradesh 594 5 1981 Gujarat 470 6 1982 Gujarat & Maharashtra 500 7 1984 Tamil Nadu & Andhra Pradesh 512 8 1985 Andhra Pradesh 5000 9 1990 Andhra Pradesh 957 10 1990 Orissa 250 11 1999 Orissa 8913 (Source: Office of the US Foreign Disaster Assistance) Death associate with noteworthy Tropical Cyclones (1970 – 2005) Typical Adverse Effects

22. Possible Risk Reduction Measures Coastal belt plantation Hazard mapping Land use Control Engineered Structures Flood Management Improving Vegetation Cover

23. Other Natural Disaster like Flood, Drought and Landslide will be covered in the next Class.

24. Assignment 1. Are their any official policy measure or legal framework to mitigate disaster in your country?

25. Thank You