Landslides are common in the Lower Himalayas. Parts of the Western Ghats also suffer from low-intensity landslides. Floods are the most common natural disaster in India. The heavy southwest monsoon rains cause the Paramount and other rivers to distend their banks, often flooding surrounding areas. Though they provide rice payday farmers with a largely dependable source of natural irrigation and fertilization, the floods can kill thousands and displace millions. Excess, erratic, or untimely monsoon rainfall may also wash away or otherwise ruin crops.
Almost all of India is flood- prone, and extreme precipitation events, such as flash floods and torrential rains, have become increasingly common in central India over the past overall decades, coinciding with rising temperatures. Mean annual precipitation totals have remained steady due to the declining frequency of weather systems that generate moderate amounts of rain. A natural disaster might be caused by earthquakes, flooding, volcanic eruption, landslide, hurricanes etc.
In order to be classified as a disaster it will have profound environmental effect and/or human loss and frequently incurs financial loss. This review elucidates the natural disasters of Tamil Nadia and its possible cause as well as the preventive/mitigation measures. Keywords: Natural starters, droughts, flash floods, cyclones, avalanches, landslides, hurricanes. Introduction At the global level, there has been considerable concern over natural disasters. Many natural disasters in India have caused havoc to the life and property of citizens and nature as a whole from time to time.
Because of this, united Nations General Assembly, in 1989, declared the decade 1990-2000 as the International Decade for Natural Disaster Reduction with the objective to reduce loss of lives and property and restrict socio-economic damage through concerted international action for appropriate management travesties, especially in the developing countries. These disasters include cyclones, floods, earthquakes, volcanic eruptions, famines, drought, landslides etc. Amongst all the ones mentioned floods and earthquakes are the most common in India.
India is no exception as it has been traditionally vulnerable to natural disasters on account of its unique gee-climatic conditions. Floods, droughts, cyclones, earthquakes and landslides have been recurrent phenomena in India due to large population growth, and migration into urban areas (De et al. , 2005). Tamil Nadia has witnessed havoc caused by yeses and storm surge in the coastal regions, earthquakes, monsoon floods, landslides, and recently the Tsunami.
Increase in urban population coupled with the construction of man-made structures often poorly built and maintained subject cities to greater levels of risk to life and property in the event Of earthquakes and other natural hazards. India is an area of 3,287,263 square kilometers and a coastline of 7516 km, with the last official census in 2001 showing a population 1. 028 billion people (NIB, 2009). Tamil Nadia covers an area of 130, 0582 SMS and has a coastline f about 1,076 SMS which is about 15% of the coastline of India (Bavarian et al. , 2011).
More than 40% of the fisher population lives within 1 km of coast and 50% of them live within 2 km of the coast. The geographical setting of Tamil Nadia makes the state vulnerable to natural disasters such as cyclones (Mascaras and Kumara 2007) floods and earthquake-induced tsunami. About 8% of the state is affected by five to six cyclones every year, of which two to three are severe. Cyclonic activities on the east coast are more severe than on the west coast, and occur mainly be;en April-May and October- November (Supply and Aircraftman, 2009).
Floods Floods are high stream flow that overflows the natural banks of the rivers and most of the times become calamitous. India is the most flood affected nation after Bangladesh. Out of total deaths by Floods in the world, (1/5) are from India. The main causes of floods are excessive rains in river catchments, poor natural drainage, Change of river course, Landslide restricting river flow, cyclone and very intense rainfall (Fig. 1). Over that past few years the rise in population is forcing large settlements along the river banks, making the country
Thou Education and Research Trust (YEAR) Stephen, 201 2 J. Cad. Indus. Rest. Volvo. 1(2) July 2012 60 policies and measures for various preventions and disaster management activities are properly implemented. From the flood hazard map of India (Fig. 1), it is seen that no area in Tamil Nadia falls in the risk zone. But within a local body area, particularly with reference to an area’s proximity to a major drainage system like rivers, canals, and also water bodies like lakes, and further with reference to contour levels/low-lying areas, flood prone area mapping has to be done.
Tamil Nadia is also subjected to annual flooding including flash floods, cloudburst floods, monsoon floods of single and multiple events, cyclonic floods, and those due to dam bursts or failure. Every year, on average thousands of people are affected, a few hundred lives are lost, thousands are rendered homeless and several hectares of crops are damaged. Every year, Flooding in India affects Tamil Nadia and the other Indian states of Assam, Briar, West Bengal, Gujarat, Arioso, Utterance, and Maharajah’s (Supply and Aircraftman, 2009). Floods are the most frequent and often the most devastating.
The cause of flood is mainly the causalities of rainfall in North east monsoon period in the state. Out of the total annual rainfall in the state, 90% is concentrated over short monsoon season of three months. As a result, heavy discharges from the rivers during this period causing widespread floods in the delta regions. Floods occur mainly in the coastal districts basin that carries 100% of the state total river flows (Poniard, 2006). Cyclones Cyclone refers to a whirl in the atmosphere with very strong winds circulating around it in anti-clockwise direction in the Northern Hemisphere and clockwise in the Southern Hemisphere.
Cyclones re intense low pressure areas with pressure increasing outwards. Cyclones can be hazardous as Cyclones are normally associated with strong winds. A storm surge is an abnormal rise of sea level near the coast caused by a Fig. 1. F-loot hazard map of India. Highly vulnerable to Floods. The most vulnerable states of India are Attar Pradesh, Briar, Assam, West Bengal, Gujarat, Arioso, Andorra Pradesh, Madhya Pradesh, Maharajah’s, Punjab and Jam and Kashmir. In 1994, a major flood killed 147 people in Kraal, 138 in Gujarat and marooned 10000 in Madhya Pradesh.
In 1995, the states of Attar Pradesh, Harlan and Raunchy Pradesh were severely hit by flood causing huge casualties. In the year 1996, a fierce flood literally paralyzed India, Thousands of people died, got homeless, were marooned in the states of Restaurants, Andorra Pradesh, Jam and Kashmir also affecting many other parts Of the country. In short, nearly every year one or the other part of the country is severely hit by Hoods and creating a shameful history for India. It is high time that the @Youth Education and Research Trust (YEAR) J.
Cad. Indus. Rest. Volvo. 1(2) July 2012 61 period (Fig. 2). The coast line starts from Publican along the east coast and extends up to Ruminatively in Sanitarium District and consists of Estuaries of ecological importance, Major and Minor ports, Fishing harbors, Monuments of international heritage, Tourist locations, Pilgrimage centers, etc. Earthquakes Earthquakes are powerful manifestations of sudden releases of strain energy accumulated within the crust and propagated as seismic waves.
The need to understand and study the phenomenon of earthquake is for a simple reason, that it is the most disastrous natural calamity for mankind. The Himalayan Frontal arc in India is amongst the most seismically active regions of the world. Even the Peninsular Stretch is extremely susceptible to Earthquakes. The Run of Ketch Earthquake of 1918 is one of the largest interplant events in the world. The first Seismological observatory in India was established in the year 1 898 in the city of Calcutta.
Over the years the department has been exponentially expanded by the Meteorological Department of India. Tamil Nadia is not as seismically active as states in the northern and western parts of the country, small to moderate earthquakes have occurred in the state of Tamil Nadia. The frequency of earthquakes is low I. E. The gap between moderate sized events is fairly long. Seismic activity in the recent past has occurred in clusters (Disgusts et al. , 2000) along the borders with Andorra Pradesh, Karakas and Kraal.
Ever tropical cyclone; as a result, sea water inundates low lying areas of coastal regions drowning human beings and lives-stock, eroding beaches and embankments, destroying vegetation and reducing soil fertility. Fig. 2. TN: Hazard Map-earthquake, Floods and Cyclone (After Poniard, 2006). Apart from strong winds, cyclones can result in heavy rains causing floods. However, the most destructive factor associated with the cyclones is the storm surge. The worst and the oldest cyclone in India was in 1 737, in Calcutta that took 300000 lives respectively.
For cyclone forecast and advance warning, the Government has strengthened the Meteorological Department, by providing Cyclone Surveillance Radars at Calcutta, Prepared, Visitation, Machinations, Madras and Karakul in the east coast and at Cochin, Goat Bombay and Bush in the west coast. As India has a vast coastline Several faults have been identified in this region out of it is extremely vulnerable to cyclone. In India, nearly 150 which many show evidence of movement (Disgusts et million people are prone to natural hazard in coastal l. , 2000) during the Holocene period. The east-west areas (Return, 1995; 1999).
Bay of Bengal is one of the trending Caver Fault, Tranquiller- Butchery Fault five cyclone prone areas of the world. The coastal and Vagina River Fault and the north-south trending regions surrounding this bay are frequently affected by Coming-Point Acclaimer Fault and Rationalizations from the sea as well as from the rivers due to Deviant Fault are some of them and run close to tropical cyclones and related storm surges and heavy major urban centers like Combaters, Madeira, rainfall. In Tamil Nadia during he years 1 990 to 1 995, Imagination, Thankful and Butchery. ND 2006 the damages caused Fig. 3. Seismic hazard map of TN (After Amateur Seismic Centre, 2012).
To property were worth 5800 million rupees (US$ 170 M) and the loss of human lives were more than 500 (Rammers, 2007). Tamil Nadia lies in the southern part of Indian peninsula and has a long east coast. The east coast is more vulnerable to cyclones and floods. Tamil Nadia has a very long coastline Of about smoke with 591 coastal villages, which is exposed to tropical cyclone arising in the Bay of Bengal and has seasonal character to Tamil Nadia.
In 2005, 9 cyclonic storms crossed Tamil Nadia and Andorra coast in a three month 62 the influence of gravity (Noncom et al. , 1972; Barnes, 1978; Hutchinson, 1988; WAP/WILL, 1990; Cruder, 1991; Cruder and Barnes, 1996). In the hilly areas of India, the sliding of huge masses of land has been a common natural disaster causing havoc to life and property. One of the worst and most disastrous landslides has been recorded in the year 1998 in the state of Outranked, when nearly 380 people were killed.
As a measure of concern many committees and other measures have been taken to protect from this natural havoc in India. In India, the regions of Himalayas and the Western Ghats are the most vulnerable to these land-slides. Fig. 4. Block diagram of a landslide (Barnes, 1974). However, it must be stated that proximity to faults does not necessarily translate into a higher hazard as compared to areas located further away, as damage from earthquakes depends on numerous factors such as subsurface geology as well as adherence to the building codes.
The seismic hazard map of India was updated in 2000 by the Bureau of Indian Standards (IBIS). According to the new map more areas of Tamil Nadia are susceptible to damage from earthquakes than previously thought (Fig. ). The city of Achaean, formerly in Zone II now lies in Zone Ill. Districts in the western part of the state, that lie along the border with Kraal also lie in Zone Ill, along with districts along the border of Andorra Pradesh and a section of the border with Karakas. The maximum intensity expected in these areas would be around MASK VII.
The rest of the state lies in Zone II. Since the earthquake database in India is still incomplete, especially with regards to earthquakes prior to the historical period (before 1800 A. D. ), these zones offer a rough guide of the earthquake hazard in any particular region and need to be regularly updated Praiseworthy and Rejuvenated, 201 1 According to GAPS data, the state of Tamil Nadia falls mostly in a region of low seismic hazard with the exception of western border areas that lie in a low to moderate hazard zone.
Butchery lies in a low hazard region. As per the 2002 Bureau of Indian Standards (IBIS) map, Tamil Nadia and Butchery fall in Zones II and Ill. Historically, parts of this region have experienced seismic activity in the MM. O range. Tamil Nadia is also prone to very severe damaging earthquakes. Its people feel much more vulnerable to earthquake-induced tsunamis since the 004 Indian Ocean tsunami, which affected the coast of Tamil Nadia destroying much of the marine biology and severely damaging the ecosystem (Government of Tamil Nadia, 2008).
Crops, settlements, trees, birds, fishes, wildlife, and properties were destroyed. Precious coral reefs and mangrove areas were crushed by the huge tsunami waves that devastated South India, an environmental and economic setback that could take years to reverse. Power and communications were totally disrupted. The damage to humans, especially women and children, and animal life, was tremendous, resulting in emotional and mental trauma (Kumar et al. 2007). Largest Instrumented Earthquake occurred in Tamil Nadia and Butchery on the 26 September 2001(11. 984 N, 80. 25 E, D=OHIO. O SMS, UTC).
A moderate earthquake occurred in the Bay of Bengal, off the coast of the union territory of Butchery, on 25 September 2001 at 20:26 PM local time resulting in three deaths and minor damage to property in Butchery and coastal Tamil Nadia. It had a magnitude of Mm=S. 5. Landslides Landslides are mass movement of rocks and debris that usually follow a cyclone, volcano or earthquake under The main causes of landslides are weak, weathered materials, physical repertory variation, Ground uplift, erosion, Earthquake, Volcanic eruptions etc.
The general and simple mitigation that are adopted or should be adopted are drainage correction, proper land-utilization, reforestation and spreading Of awareness. Landslides have represented 4. 89% of the total natural disasters that occurred worldwide during the years 1 990 – 2005 (www. Me-data. Net). Landslide is one of the major natural hazards that are commonly experienced in hilly terrains all over the world. Landslides are affect at least 15 per cent of the land area of India-?an area which exceeds 2 0. 49 million km .
In India the incidence of landslides in Himalayas and other hill ranges is an annual and recurring phenomenon. There is a variation in the degree of landslide incidences in various hill ranges (Table 1). Table 1. Incidences of landslides in India. Region Incidences of landslides Himalayas High to very high North eastern Hills High Western Ghats and the Inklings Moderate to high Eastern Ghats and Evangelically Low For example, the landslide incidences are high to very high in Himalayas, high in Northeastern hill ranges, high to moderate in Western Ghats and Inklings and low in the hill ranges of Eastern Ghats and Vanishes.
The landslide hazard conation atlas of India published by Building Materials and Technology Promotion Council (EMPTY), Government of India reveals that the Inklings district of Tamil Nadia state is one of the severe to very high landslide hazard prone areas Of India. 63 rain at O’Connor resulting in washing away of one woman and 2 Children. The rainfall recorded at O’Connor and Kodak was 145. 2 mm and 142. 2 mm respectively. On the 19 there was heavy landslide of 1 00 yards in width and about 1. 00 km in length in Sells of Kettle Village of O’Connor Talk resulting In filling up of a Valley of 30′- 50′.
The heaviest rainfall of the day was 187. 6 mm at O’Connor. On 20. 1 1. 1979 also, there was heavy rain of 102. 2 mm at O’Connor and a heavy landslide at Sells in which a house was completely buried in the debris along with 2 women and 3 children. The rainfall recorded on that day at Agitator, Kodak and Kandahar was 90. 4 mm, 99. 8 mm and 78. 0 mm respectively. There was heavy SST rainfall of 71. 0 mm at Devalue on 21 . On 28. 11. 79 also there was heavy rain of 144. 2 mm at O’Connor. the 25 October 1990: The North East Monsoon was heavy and there was a ‘cloud burst’.
More than 35 families were buried alive in a place called Gadded. November 1993: There was another ‘cloud burst’ on 11 11-1993 in the upper reach of Marmalade of O’Connor Talk, about 18 huts situated below the road and washing away O’Connor MET Ghats Road for about la km. The Road traffic was suspended for more than a fort night. 12 persons lost their live and 15 persons missing. It is laid that 21 passengers were washed away with two buses. An important highway, sheared stretched of rail road for about 300 m. H 1 1 December 1 998: Due to continuous rain fall, one big boulder weighing about 20 m tones fell on the O’Connor Metallurgy main road and the road as closed for traffic, the rock was blasted and earth slips were removed and traffic was resumed from 14. 12. 98. December 2001: Due to continuous rainfall, two massive landslides occurred near puddle on the Counterrevolutionary high way damaging Non bridges resulting in the complete closure of traffic. In addition a closer damage was also caused to the railway track between O’Connor and Metallurgy.
Bridge no 55 near hill grove railway station was completely damaged and Bridge No 56 was also damaged. November 2006: Consequent upon continuous heavy rains in the Inkling Hills, numerous landslides were reported to have occurred at the early ours on 14. 11. 2006 killing one and injuring three persons and disrupting traffic in NH 67 and blocking of Mountain Rail track between Metallurgy and O’Connor (inklings. Nice. In; Sympathy et al. , 2010). Drought Drought is a temporary aberration unlike aridity, which is a permanent feature of climate.
It is a normal, recurrent feature of climate and occurs in all climatic regimes and is usually characterized in terms of its spatial extension, intensity and duration. Conditions of drought appear when the rainfall is deficient in relation to the statistical multi-year average for a region, over an extended erred of a season or year, or even more (Manual for drought management, 2009). There are three types of droughts; Meteorological drought is when the actual rainfall is much less than the climatologically mean of the area.
Unprecedented rains triggered about a hundred landslides within an area of 250 sq. SMS in the district during 1978. Nearly 200 landslides were recorded during 1979 and causing loss of life and severe damage to property. Though the Inkling and other mountainous areas are known to be susceptible to landslides, occurrences of such magnitude were unknown earlier. A total of 8 landslides of medium to large size occurred on 14 November, 2006 along NH between Cellar and Pudenda villages and along Mountain Railway track between Dearly and Barbital stations.
In the recent times casualties and damage due to landslides have increased in the Inkling Hills. More than 110 landslides were reported within five days from 10 to 15 November, 2009, and taken away about 80 human lives, also the vast damage reported on houses, roads and railway lines. This taught the lesson for the need and urgency of landslide planning in Inklings among the scientific community and planners (Sympathy et al. 2010). Some of the major landslides of Inklings rd 23 October 1865: Worst Storm on record occurred around Toy and O’Connor.
O’Connor Railway station was covered with water up to 5 feet deep. In Toy Lake rose up to top Of willow bound and threatened to breach it. November 1891: Storm caused many landslips on the O’Connor Ghats, and did great damage to the Agitator Metaphysical road. December 1 902: Twenty one inches of rain (three times the average amount) fell in that month in O’Connor, and at Agitator 24 inches (six times the average amount) was received, of which 8. 45 inches fell in a single night.
The O’Connor railway was blocked for a month the old and new O’Connor railway was blocked for a month the old and new O’Connor Ghats roads for nearly as long and all the traffic of the eastern side of the plateau was thrown upon the Agitator Ghats, which was itself in a perilous condition slips having occurred throughout and being serious in six places out of its twenty one miles length. the 4 October 1905: 6. 8 inches of rain fell at O’Connor in three hours and the O’Connor river and its effluents came down in heavy and sudden floods, the former sweeping right over the parapet of the bridge near the realization.
The families of the station staff had to be rescued by breaking open the back windows of their quarters with crowbars. the 5 November 1978: mm of rain was recorded at Toy of which 243 MM was during the night between 5. 00 pm the of 4 and 8. 00 am of 5th. Many people were killed in Toy on account of houses collapses, landslides and drowning. Reports were also received regarding the causalities due to landslides and floods in Kohlrabies; Mitochondria; Dossal and Galatia areas of Dogmatically Talk and Manhattan of O’Connor Talk. the November 1979: Heavy rainfall started from 12 November 1 979 and the highest rain fall as 114. Mm at the Kodak.
On 13 it was 149. 4 mm at O’Connor and 169. 9 the mm at Kodak. On the 15 night heavy landslide had the occurred at Duodecimal, on 16 night there was heavy 64 Fig. 5. Map of drought prone districts of India (Drought prone areas are in red). The country as a whole may have a normal monsoon, but different meteorological districts and sub-divisions can have below normal rainfall. The rainfall categories for smaller areas are defined by their deviation from a meteorological area’s normal rainfall (Table 2). Table 2. Rainfall categories.
Category Excess Normal Deficient Scanty Deviation 20% or more above aroma 19% above normal-19% below normal 20% below normal-59% below normal 60% or more below normal Meteorological history of droughts in India During 1871-2002, there were 22 major drought years, defined as years with All India Summer Monsoon Rainfall (ASSAM) less than one standard deviation below the mean (I. E. Anomaly below-10%): 1873, 1877, 1899, 1901, 1904, 1905, 1911 , 1918, 1920, 1941, 195 1, 1965, 1966, 1968, 1972, 1974, 1979, 1982, 1985, 1986, 1987, 2002. The frequency of drought has varied over the decades. From 1899 to 1920, there were 7 drought years.
The incidence of drought came down teens 1941 and 1 965 when the country witnessed just three drought years. Again, during 1965-87, of the 21 years, 10 were drought years and the increased free ounce was attributed to the El Nine Southern Oscillation (ONES). Among the drought years, the 1 987 drought was one of the worst droughts of the century, with an overall rainfall deficiency of 19%. It affected 59-60% of the crop area and a population of 285 million. In 2002 too, the overall rainfall deficiency for the country as a whole was 19%. Over 300 million people spread over 18 States were affected by drought in varying degrees.
Around 150 million cattle were affected due to lack of fodder and water. Food grains production registered the steepest fall of 29 million tones. No other drought in the past had caused reduction in food grain production to this extent (Samara, 2004). Hydrological drought results from the depletion of surface water causing very low stream flow and drying of lakes, rivers and reservoirs and Agricultural drought resulting from depletion of soil moisture resulting in acute crop stress and fall in agricultural productivity. India has been severely affected by droughts over the past years claiming millions of lives.
The agriculture in India is totally dependent on rains, which when is not adequate results in poor yielding of crops. This is particularly true of major drought-prone regions such as southern and eastern Maharajah’s, northern Karakas, Andorra Pradesh, Arioso, Gujarat, and Restaurants (Fig. 5). In India there is also a history of droughts leading to famines. During the major drought of 2000-2001, a total of eight states had fallen short of crops. Government policies and preventions play the most significant role in coping up with these environmental disasters. Drought is a normal, recurrent feature of climate.