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Here is an essay on the ‘Disaster Warning System in India’ for class 7, 8, 9, 10, 11 and 12. Find paragraphs, long and short essays on the ‘Disaster Warning System in India’ especially written for school and college students.
Essay on the Disaster Warning System in India
Essay Contents:
- Essay on the Introduction to Disaster Warning System
- Essay on the Modified Mercalli Intensity Scale
- Essay on Warnings about Cyclone
- Essay on Structural Measures against Tsunamis
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1. Essay on the Introduction to Disaster Warning System:
In India, the Department of Ocean Development in association with Department of Science and Technology (DST), Department of Space (DOS) and CSIR Laboratories, is setting up an Early Warning System for Tsunami and Storm Surges in the Indian Ocean. The existing analogue Cyclone Warning Dissemination System of India Meteorological Department (IMD), with 250 receivers installed along the Indian coast, is to be replaced with a state-of-art system.
The new system will provide more lead time to the disaster management officials and better voice quality for easy comprehension. As regard to the earthquake, at present there is no advance warning system available, the world over, that can forecast the occurrences of earthquake. However, the observational network of seismological observatories maintained and operated by IMD is capable of effective surveillance in the country.
Generation of disaster warning is a multi-institutional endeavor. Different institutions namely, Geological Survey of India, Central Water Commission and Defence Research and Development Organization are responsible for early warning for landslides, flood and avalanches respectively, while IMD is mandated to monitor the tropical cyclones and earthquakes in the country and provide necessary information/warnings to Government officials and public for disaster mitigation.
2. Essay on the Modified Mercalli Intensity Scale:
The effect of an earthquake on the Earth’s surface is called the intensity. The intensity scale consists of a series of certain key responses such as people awakening, movement of furniture, damage to chimneys, and finally total destruction. Although numerous intensity scales have been developed over the last several hundred years to evaluate the effects of earthquakes, the one currently used in the United States is the Modified Mercalli (MM) Intensity Scale.
It was developed in 1931 by the American seismologists Harry Wood and Frank Neumann. This scale, composed of increasing levels of intensity that range from imperceptible shaking to catastrophic destruction, is designated by Roman numerals. It does not have a mathematical basis; instead it is an arbitrary ranking based on observed effects.
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The Modified Mercalli Intensity value assigned to a specific site after an earthquake has a more meaningful measure of severity to the non-scientist than the magnitude because intensity refers to the effects actually experienced at that place. The lower numbers of the intensity scale generally deal with the manner in which the earthquake is felt by people.
The higher numbers of the scale are based on observed structural damage. Structural engineers usually contribute information for assigning intensity values of VIII or above. The following is an abbreviated description of the levels of Modified Mercalli intensity.
While the Mercalli scale describes the intensity of an earthquake based on its observed effects, the Richter scale describes the earthquake’s magnitude by measuring the seismic waves that cause the earthquake. The two scales have different applications and measurement techniques. The Mercalli scale is linear and the Richter scale is logarithmic, i.e., a magnitude 5 earthquake is ten times as intense as a magnitude 4 earthquake.
3. Essay on Warnings about Cyclone:
1. The cyclone warnings are issued to state government officials in four stages. The First Stage warning known as “PRE CYCLONE WATCH” issued 72 hours in advance contains early warning about the development of a cyclonic disturbance in the north Indian Ocean, its likely intensification into a tropical cyclone and the coastal belt likely to experience adverse weather.
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This early warning bulletin is issued by the Director General of Meteorology himself and is addressed to the Cabinet Secretary and other senior officers of the Government of India including the Chief Secretaries of concerned maritime states.
2. The Second Stage warning known as “CYCLONE ALERT” is issued at least 48 hrs. in advance of the expected commencement of adverse weather over the coastal areas. It contains information on the location and intensity of the storm likely direction of its movement, intensification, coastal districts likely to experience adverse weather and advice to fishermen, general public, media and disaster managers. This is issued by the concerned ACWCs/CWCs and CWD at HQ.
3. The Third Stage warning known as “CYCLONE WARNING” issued at least 24 hours in advance of the expected commencement of adverse weather over the coastal areas. Landfall point is forecast at this stage. These warnings are issued by ACWCs/CWCs/ and CWD at HQ at 3 hourly interval giving the latest position of cyclone and its intensity, likely point and time of landfall, associated heavy rainfall, strong wind and storm surge along with their impact and advice to general public, media, fishermen and disaster managers.
4. The Fourth Stage of warning known as “POST LANDFALL OUTLOOK” is issued by the concerned ACWCs/CWCs/and CWD at HQ at least 12 hours in advance of expected time of landfall. It gives likely direction of movement of the cyclone after its landfall and adverse weather likely to be experienced in the interior areas.
Different color codes as mentioned below are being used since post-monsoon season of 2006 the different stages of the cyclone warning bulletins as desired by the National Disaster Management.
During disturbed weather over the Bay of Bengal and Arabian Sea, the ports likely to be affected are warned by concerned ACWCs/CWCs by advising the port authorities through port warnings to hoist appropriate Storm Warning Signals. The Department also issues “Fleet Forecast” for Indian Navy, Coastal Bulletins for Indian coastal areas covering up to 75 km from the coast line and sea area bulletins for the sea areas beyond 75 km.
The special warnings are issued for fishermen four times a day in normal weather and every three hourly in accordance with the four stage warning in case of disturbed weather. The general public, the coastal residents and fishermen are warned through State Government officials and broadcast of warnings through All India Radio and National Television (Doordarshan) telecast programmes in national and regional hook-up. A system of warning dissemination for fishermen through World Space Digital Based radio receivers is being planned.
4. Essay on Structural Measures against Tsunamis:
Structures such as dikes play a crucial role in preventing disasters by controlling tsunamis, floods, debris flows, landslides, and other natural phenomena. However, structural measures alone cannot prevent all disasters because they cannot mitigate damages when the hazard exceeds the level that the structures are designed to withstand. The Great East Japan Earthquake (GEJE) demonstrated the limitations of Japan’s existing disaster management systems, which relied too heavily on dikes and other structures. Damage can be kept to a minimum by multilayered approaches to disaster mitigation that include structural and non-structural measures and that ensure the safe evacuation of residents.
Dikes, dams, and other structures are regarded as core measures in disaster risk management in Japan. Japan has constructed dikes to mitigate flooding for nearly 2,000 years. The first dike system was constructed in the Yodogara river in Osaka in the fourth century.
The Japanese used dike systems to protect crucial areas, such as castles and residential areas, in the middle and early modern periods. The government established after the Meiji Revolution in the late nineteenth century has promoted structural measures to control floods, high tides, landslides, and tsunamis by employing modern technology introduced from the Netherlands and other Western countries.
Disaster damage had substantially decreased because of concentrated investment in structural measures. Surrounded by seas, Japan has an extremely long, geographically complex coastline of approximately 35,000 kilometers. People, productive assets, and social capital are concentrated on small coastal plains over a limited land area.
Not only are Japan’s coastal areas situated where earthquakes are exceptionally common, but they are also subject to harsh natural events, such as typhoons and winter ocean storms. Historically, the country has suffered severe damage from tsunamis, storm surges, ocean waves, and other natural phenomena. To protect life and property concentrated near its coastline, the country has been developing coastal and port facilities for the last half century.
The coastal zone of Viet Nam is 3,260 kilometres long, extending through the territories of 24 provinces and cities. Interaction between the land and the sea, between the dynamic forces of rivers and the sea and between natural and human processes occurs in this zone. On average, river mouths are found every 20 kilometres along the Viet Namese coast. Landforms are diverse and natural calamities occur frequently, causing multidirectional impacts on natural and socio-economic conditions. In particular, coastal erosion generates many difficulties for the coastal population.
Some coastal processes (for example, wind, waves and tides) have been identified as key factors vis-a-vis influencing coastal erosion. Human activities (inter alia vegetation clearance, harbour development, land reclamation) may often result in sediment addition or reduction.
During a tsunami impact, coastal erosion is caused by the rundown of the water, which will remove a high percentage of sediment and debris from the land. Modification of soil composition after such an event should be taken into account during rehabilitation activities.
Mitigation measures currently in use are hard structures (for example, walls, rip-raps), soft structures (beach nourishment, mangrove plantation) and a combination of the two. The effectiveness of each mitigation measure can only be analysed on a case-by-case basis.
Extreme erosion in Viet Nam depends on several factors that should be further investigated in order to respond in an effective manner. Even though human pressure has been recorded as one of the main causes, to date, the construction of the Dinh Vu Dam seems to have decreased erosion in some regions of the country.
Protective measures such as dykes and revetments and the plantation of trees are used to control erosion. The Viet Namese Government is investing in research for effective protective measures.