Tuesday, July 3, 2012

INDIA Hazard Profile

India, due to its, physio-graphic and climatic conditions is one of the most disaster prone areas of the world. It is vulnerable to windstorms from both the Arabian Sea and Bay of Bengal. There are active crustal movements in the Himalaya leading to earthquakes. About 58.7 % of the toatal land mass is prone to earthquake of moderate to very high intensity. The region was hit by Uttarkashi Earthquake (1991), Killari Earthquake (1993), Koyana Earthquake (1997), Chamoli Earthquake (1999), and Bhuj earthquake (2001), Jammu & Kashmir Earthquake (2005). The Himalayas being a fairly young mountain range is undergoing constant geological changes resulting in landslides. Floods brought about by heavy rain and drought in arid and semi arid areas. About 12 % of the o f the total land mass is flood prone and 68 % of the arable land is vulnerable to drought. The Western region of the country is represented by the Thar Desert and the central India by the Deccan Plateau face recurring droughts due to acute shortage of rainfall. India has increasingly become vulnerable to Tsunamis since the 2004 Indian Ocean Tsunami. India has a coastline running 7600 km long; as a result is repeatedly threatened by cyclones. The table below shows major disasters in the known history of India:
SR. NO. Name of Event Year Fatalities
1. Maharashtra Earthquake 1618 2,000
2. Bengal Earthquake 1737 300,000
3. Bengal Cyclone 1864 60,000
4. The Great Famine of Southern India 1876-1878 5.5 million
5. Maharashtra Cyclone 1882 100,000
6. The Great Indian famine 1896-1897 1.25 million to 10 million
7. Kangra earthquake 1905 20,000
8. Bihar Earthquake 1934 6,000
9. Bengal Cyclone 1970 500,000 (include Pakistan and Bangladesh also)
10. Drought 1972 200 million people affected
11. Andhra Pradesh Cyclone 1977 10,000
12. Drought in Haryana & Punjab 1987 300 million people affected
13. Latur Earthquake 1993 7,928 death and 30,000 injured
14. Orissa Super Cyclone 1999 10,000
15. Gujarat Earthquake 2001 25,000
16. Indian Ocean Tsunami 2004 10,749 deaths 5,640 persons missing
17. Kashmir Earthquake 2005 86000 deaths (include Kashmir & Pakistan)
18. Kosi Floods 2008 527
19. Cyclone Nisha of Tamil Nadu 2008 204



Identifying the hazards:

Natural disasters
Earthquake: India is having a high risk towards Earthquakes. More than 58 per cent of India’s land area is under threat of moderate to severe seismic hazard. During the last 20 years, India has experienced 10 major earthquakes that have resulted in more than 35,000 deaths. The most vulnerable areas, according to the present seismic zone map of India include the Himalayan and sub-Himalayan regions, Kutch and the Andaman and Nicobar Islands. Depending on varying degrees of seismicity, the entire country can be divided into the following seismic regions: Of the earthquake-prone areas, 12% is prone to very severe earthquakes, 18% to severe earthquakes and 25% to damageable earthquakes.

Though the regions of the country away from the Himalayas and other inter-plate boundaries were considered to be relatively safe from damaging earthquakes, the presence of a large number of non- engineering structures and buildings with poor foundations in these areas make these regions also susceptible to earthquakes. In the recent past, even these areas also have experienced earthquake, of lower magnitude than the Himalayan earthquakes. The North-Eastern part of the country continues to experience moderate to strong earthquakes. On an average, this region experiences an earthquake with magnitude greater than 5.0 every year. The Andaman and Nicobar Islands are situated on an inter-plate boundary and therefore are likely to experience damaging earthquakes frequently. The increase in earthquake risk in India in recent times is caused due to a spurt in developmental activities driven by urbanization, economic development and the globalization of India’s economy. The increase in the use of high-technology equipment and tools in manufacturing and service industries have also made them susceptible to disruption due to relatively moderate ground shaking.

Flood and drought: The country receives an annual precipitation of 400 million - hectare meters. Of the annual rainfall, 75% is received during four months of monsoon (June- September) and, as a result, almost all the rivers carry heavy discharge during this period. The flood hazard is compounded by the problems of sediment deposition, drainage congestion and synchronization of river floods with sea tides in the coastal plains. The area vulnerable to floods is 40 million hectares and the average area affected by floods annually is about 8 million hectares. About 30 million people are affected by flood every year. Floods in the Indo–Gangetic–Brahmaputra plains are an annual feature. On an average, a few hundred lives are lost, millions are rendered homeless and several hectares of crops are damaged every year Around 68% arable land of the country is prone to drought in varying degrees. Drought prone areas comprise 108. 11 million hectares out of a total land area of 329 Million hectares. About 50 million people are affected annually by drought. Of approximately 90 million hectares of rain-fed areas, about 40 million hectares are prone to scanty or no rain.

Cyclone: India’s long coastline of 7,516 kilometer is exposed to nearly 10 per cent of the world’s tropical cyclones. Of these, the majority has their initial genesis over the Bay of Bengal and strike the east coast of India. On an average, five to six tropical cyclones form every year, of which two or three could be severe. Cyclones occur frequently on both the coasts (The west coast - Arabian Sea; and the east coast - Bay of Bengal). More cyclones occur in the Bay of Bengal than in the Arabian Sea and the ratio is approximately 4:1. An analysis of the frequency of cyclones on the east and west coasts of India  between 1891 and 1990 shows that nearly 262 cyclones occurred (92 severe) in a 50 km wide strip on the east coast. Less severe cyclonic activity has been noticed on the west coast, with 33 cyclones occurring in the same period, out of which 19  of these were severe. In India, Tropical cyclones occur in the months of May-June and October-November. The cyclones of severe intensity and frequency in the north Indian Ocean are bi-modal in character, with their primary peak in November and secondary peak in May.  The disaster potential is particularly high at the time of landfall in the north Indian Ocean (Bay of Bengal and the Arabian Sea) due to the accompanying destructive wind, storm surges and torrential rainfall.  Of these, storm surges are the greatest killers of a cyclone, by which sea water inundates low lying areas of coastal regions and causes heavy floods, erodes beaches and embankments, destroys vegetation and reduces soil fertility.


Landslide: In the hilly terrain of India including the Himalayas, landslides have been a major and widely spread natural disasters that often strike life and property and occupy a position of major concern. One of the worst tragedies took place at Malpa Uttarkhand (UP) on 11th and 17th August 1998 when nearly 380 people were killed when massive landslides washed away the entire village. This included 60 pilgrims going to Lake Mansarovar in Tibet. In 2010 Cloudburst led flash mudslides and flash floods killed 196 people, including six foreigners and injured more than 400 and swept away number of houses, sweeping away buildings, bus stand and military installations in trans Himalaya Leh town of Jammu and Kashmir. Giving due consideration to the severity of the problem various land reform measures have been initiated as mitigation measures. Landslides occur in the hilly regions such as the Himalayas, North-East India, the Nilgiris, and Eastern and Western Ghats.

Avalanche: Avalanches are river like speedy flow of snow or ice descending from the mountain tops. Avalanches are very damaging and cause huge loss to life and property. In Himalayas, avalanches are common in Drass, Pir Panijat, Lahaul-Spiti and Badrinath areas. As per Snow and Avalanche Study Establishment (SASE), of Defence Research and Development Organisation (DRDO), on an average around 30 people are killed every year due to this disaster in various zones of the Himalayas. Beside killing people, avalanches also damage the roads and others properties and settlements falling in its way.
Area Prone to Avalanches
  • Avalanches are common in Himalayan region above 3500m elevation.
  • Very frequent on slopes of 30-45°.
  • Convex slopes more prone to this disaster.
  • North facing slope have avalanches in winter and south facing slopes during spring.
  • Slopes covered with grass more prone to this hazard.

Forest Fire: Forest or bush fire, though not causing much loss to human life, is a major hazard for forest cover in the country. As per Forest Survey of India report, 50 per cent of the forest cover of the country is fire prone, out of which 6.17 per cent is prone to severe fire damage causing extensive loss to forest vegetation and environment. Average annual physical loss due to forest fire in the country is estimated to worth Rs. 440 crores. The major loss due to forest fire is caused to the environment which gets adversely affected by this calamity. The degradation of climate, soil and water quality, loss of wildlife and its habitat, deterioration of human health, depletion of ozone layer, etc. along with direct loss to timber are the major adverse impact of forest fires. The coniferous forests in the Himalayan region are very susceptible to fire and every year there are one or more major fire incidences in these areas. The other parts of the country dominated by deciduous forest are also damaged by fire up to an extent. It is worth mentioning that in India 90 per cent of the forest fires are man­-made (intentionally or unintentionally).

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