CYCLONES

DEFINATIONA cyclone is a low pressure area surrounded by high pressure area form all sides . It is a circular or elliptical in shape . Winds move from all sides to central low . They assume anticlockwise direction in the northern hemisphere and clockwise in the southern hemisphere due to cariolis effect.

ITS OF TWO TYPES

TEMPARERATE C YCLONE

TROPICAL CYCLONE

CHARACTERSTICS OF CYCLONESTo make the most efficient analysis of available data in the vicinity of typhoon, you must be familiar with the normal wind, pressure, temperature, clouds and weather pattern associated with these storms.

1.SURFACE WINDS The surface winds blow inward in a counterclockwise direction toward the center. The winds in the left-rear quadrant have the greatest angle of inflow (in the Northern Hemisphere). The diameter of the area affected by hurricane or typhoon force winds may be in excess of 100 miles in large storms or as small as 25 to 35 miles. Gale-force winds sometimes cover an area 500 to 800 miles or more. The maximum extent of strong winds is usually in the direction of the major subtropical high-pressure center, which is most frequently found to the right of the storm’s path in the Northern Hemisphere. Surface wind speeds of 140 knots have been successfully recorded, but accurate measurements of peak wind speeds in large mature storms have not been possible with any reliable degree of accuracy.

CHARACTERSTICS OF CYCLONES• SURFACE PRESSURE.— The sea-level isobars are

an excellent tool with which to analyze these storms. The isobars take on a nearly symmetrical or elliptical shape, although deformations in the isobaric pattern are not uncommon. For instance, the tightest isobaric spacing (strongest pressure gradient) is found to the right of a storm’s line of movement, and a trough often extends southward from these storms. The central pressures of mature storms are well below average. Central pressures of 890 to 930 millibarsare not uncommon.

CHARACTERSTICS OF CYCLONES• SURFACECE TEMPERATURE.— In contrast to extratropical cyclones,

the tropical cyclone may show no cooling, or very little, toward the storm center. This indicates that the horizontal adiabatic cooling caused by lower pressures is largely offset by the heat added through the condensation process. Upper-air temperatures have been found warmer by 5 ‘C or more.

• CLOUDS.— The cloud patterns of tropical cyclones also differ from those of extratropical cyclones. In mature tropical cyclones, almost all the cloud forms are present, but by and large the most significant clouds are the heavy cumulus and cumulonimbus which spiral inward toward the outer edge of the eye. These spiral bands, especially the leading ones, are also referred to as BARS. Cirrus and Cirrostratus occupy the largest portion of the sky over these storms. In fact, cirrus, becoming more dense, then changing to cirrostratus and lowering somewhat is more often than not a mariner’s first indication of an approaching distant storm or the development of one in the near vicinity. The appearance of the sky is very similar to that of an approaching warm front. A typical cloud distribution chart for a tropical cyclone is found in figure 9-3-7.

CHARACTERSTICS OF CYCLONESTHE EYE.— The eye of a storm is one of the oddest phenomena known in meteorology. Precipitation

ceases abruptly at the boundary of a well-developed eye; the sky partly clears; the sun or stars become

visible; the wind subsides to less than 15 knots, and at times there is a dead calm. In mature storms, the eye’s diameter averages about 15 miles, but it may attain 40 miles in large typhoons. The eye is not always circular;

sometimes it becomes elongated and even diffuse with a double structure appearance. The eye is

constantly undergoing transformation and does not stay in a steady state.

INTENSITY CLASSIFICATION• A tropical depression is the lowest category that the Japan Meteorological Agency

uses and is the term used for a tropical system that has wind speeds not exceeding 33 knots (38 mph; 61 km/h).[7] A tropical depression is upgraded to a tropical storm should its sustained wind speeds exceed 34 knots (39 mph; 63 km/h). Tropical storms also receive official names from RSMC Tokyo.[7] Should the storm intensify further and reach sustained wind speeds of 48 knots (55 mph; 89 km/h) then it will be classified as a severe tropical storm.[7] Once the system's maximum sustained winds reach wind speeds of 64 knots (74 mph; 119 km/h), the JMA will designate the tropical cyclone as a typhoon—the highest category on its scale.[7]

• From 2009 the Hong Kong Observatory started to further divide typhoons into three different classifications: typhoon, severe typhoon and super typhoon.[8] A typhoon has wind speed of 64-79 knots (73-91 mph; 118-149 km/h), a severe typhoon has winds of at least 80 knots (92 mph; 150 km/h), and a super typhoon has winds of at least 100 knots (120 mph; 190 km/h).[8] The United States' Joint Typhoon Warning Center (JTWC) unofficially classifies typhoons with wind speeds of at least 130 knots (67 m/s; 150 mph; 241 km/h)—the equivalent of a strong Category 4 storm in the Saffir-Simpson scale—as super typhoons.[9] However, the maximum sustained wind speed measurements that the JTWC uses are based on a 1-minute averaging period, akin to the U.S.' National Hurricane Center and Central Pacific Hurricane Center. As a result, the JTWC's wind reports are higher than JMA's measurements, as the latter are based on a 10-minute averaging interval.[10]

INTENSITY CLASSIFICATION

CATEGORY SUBSTAINED WINDS

TYPHOON 64 – 84 KNOTS 118 - 156 KM/H

SEVERE TROPICAL STORM

48 - 63 KNOTS89 - 117 KM/H

TROPICAL STORM 34 -47 KNOTS 62 - 88 KM/H

TROPICAL DISPERSION

< 33 KNOTS< 61 KM/H

FORMATION OF CYCLONES• In tropical oceans, the water in the oceans' surface layer heated by the direct solar

radiation. As a result, the air above the tropical oceans is characterized by high temperature and humidity, resulting in air inflation that easily leads to low density per unit volume of air. Weak wind near the equator causes the lighter air to soar and incur convection that further attracts inflow of surrounding cooler air. The intake air then warms up and soars again, creating a positive feedback cycle that eventually forms an air column with high temperature, light weight and low density. This is how the tropical depression forms.

• The air flows from high pressure towards low pressure as if the water flows from high to low elevation. The surrounding air with higher pressure will flow towards where the pressure is lower, creating the "wind." As the area for direct solar radiation moves northward away from the equator in summer, the southeasterly trade wind in the Southern Hemisphere crosses the equator and penetrates into the Northern Hemisphere in the form of southwest monsoon, which has heads-on encounter with the northeasterly trade wind in the Northern Hemisphere and forces the air in this area to soar, creating more convection. Furthermore, the wind convergence resulting from the southwesterly and the northeasterly trade winds often cause air turbulence and whirlpool. These convergence effects, when continually enhanced by the convection activity, further deepens the existing low-pressure vortex, resulting in more and faster ambient air flow been drawing into the vortex center. Faster inflow corresponds to higher wind speed which, when the near-ground maximum speed reaches or exceeds 62 km per hour or 17.2 meter per second, is characteristic of a typhoon.

FORMATION OF CYCLONES

NAMING OF CYCLONES• Tropical cyclones have officially been named since 1945 and are named for

a variety of reasons, which include to facilitate communications between forecasters and the public when forecasts, watches, and warnings are issued. Names also reduce confusion about what storm is being described, as more than one can occur in the same region at the same time.[1] The official practice of naming tropical cyclones started in 1945 within the Western Pacific and was gradually extended out until 2004, when the Indian Meteorological Department started to name cyclonic storms within the North Indian ocean. Names were first given to storms by Australian meteorologist Clement Wragge from 1887, Before the official practice of naming of tropical cyclones began, significant tropical cyclones were named after annoying politicians, mythological creatures, saints and place names. Names are drawn in order from predetermined lists (see Lists of tropical cyclone names) and are usually assigned to tropical cyclones with one-, three-, or ten-minute sustained wind speeds of more than 65 km/h (40 mph) depending on which area it originates. However, standards vary from basin to basin with some tropical depressions named in the Western Pacific, while within the Southern Hemisphere tropical cyclones have to have a significant amount of gale-force winds occurring around the center before they are named.

EFFECTS OF CYCLONES• The main effects of tropical cyclones include heavy rain, strong

wind, large storm surges at landfall, and tornadoes. The destruction from a tropical cyclone depends mainly on its intensity, its size, and its location. Tropical cyclones act to remove forest canopy as well as change the landscape near coastal areas, by moving and reshaping sand dunes and causing extensive erosion along the coast. Even well inland, heavy rainfall can lead to mudslides and landslides in mountainous areas. Their effects can be sensed over time by studying the concentration of the Oxygen-18 isotope within caves within the vicinity of cyclones' paths.

• After the cyclone has passed, devastation often continues. Standing water can cause the spread of disease, and transportation or communications infrastructure may have been destroyed, hampering clean-up and rescue efforts. Nearly two million people have died globally due to tropical cyclones. Despite their devastating effects, tropical cyclones are also beneficial, by potentially bringing rain to dry areas and moving heat from the tropics poleward. Out at sea, ships take advantage of their known characteristics by navigating through their weaker, western half.

EFFECTS OF CYCLONESAT SEA• A mature tropical cyclone can release heat at a rate upwards of

6x1014 watts.[1] Tropical cyclones on the open sea cause large waves, heavy rain, and high winds, disrupting international shipping and, at times, causing shipwrecks.[2] Generally, after its passage, a tropical cyclone stirs up ocean water, lowering sea surface temperatures behind it.[3] This cool wake can cause the region to be less favorable for a subsequent tropical cyclone. On rare occasions, tropical cyclones may actually do the opposite. 2005's Hurricane Dennis blew warm water behind it, contributing to the unprecedented intensity of Hurricane Emily, which followed it closely.[4] Hurricanes help to maintain the global heat balance by moving warm, moist tropical air to the mid-latitudes and polar regions.[5] Were it not for the movement of heat poleward(through other means as well as hurricanes), the tropical regions would be unbearably hot.

EFFECTS OF CYCLONESSTORM SURGE

• The aftermath of Hurricane Katrina in Gulfport, Mississippi. Katrina was the costliest tropical cyclone in United States history.

• See also: Storm surge• The storm surge, or the increase in sea level due to the

cyclone, is typically the worst effect from landfallingtropical cyclones, historically resulting in 90% of tropical cyclone deaths.[13] The relatively quick surge in sea level can move miles/kilometers inland, flooding homes and cutting off escape routes. The storm surges and winds of hurricanes may be destructive to human-made structures, but they also stir up the waters of coastal estuaries, which are typically important fish breeding locales.

EFFECTS OF CYCLONESHEAVY RAINFALL• The thunderstorm activity in a tropical cyclone produces intense rainfall,

potentially resulting in flooding, mudslides, and landslides. Inland areas are particularly vulnerable to freshwater flooding, due to residents not preparing adequately.[14] Heavy inland rainfall eventually flows into coastal estuaries, damaging marine life in coastal estuaries.[15] The wet environment in the aftermath of a tropical cyclone, combined with the destruction of sanitation facilities and a warm tropical climate, can induce epidemics of disease which claim lives long after the storm passes.[13] Infections of cuts and bruises can be greatly amplified by wading in sewage-polluted water. Large areas of standing water caused by flooding also contribute to mosquito-borne illnesses. Furthermore, crowded evacuees in shelters increase the risk of disease propagation.[13]

• Flooding in Seminole County, Florida from Tropical Storm Fay (2008)• Although cyclones take an enormous toll in lives and personal property, they may

be important factors in the precipitation regimes of places they affect and bring much-needed precipitation to otherwise dry regions. Hurricanes in the eastern north Pacific often supply moisture to the Southwestern United States and parts of Mexico.[16] Japan receives over half of its rainfall from typhoons.[17] Hurricane Camille averted drought conditions and ended water deficits along much of its path,[18] though it also killed 259 people and caused $9.14 billion (2005 USD) in damage.

EFFECTS OF CYCLONES

DEATHS

• During the last two centuries, tropical cyclones have been responsible for the deaths of about 1.9 million people worldwide. It is estimated that 10,000 people per year perish due to tropical cyclones.[21] The deadliest tropical cyclone was the 1970 Bhola cyclone, which had a death toll of anywhere from 300,000 to 500,000 lives.

EFFECTS OF CYCLONESRECONSTURCTION AND REPOUPLATION

• Aerial image of destroyed homes in Punta Gorda, Florida, following Hurricane Charley

• While tropical cyclones may well seriously damage settlement, total destruction encourages rebuilding. For example, the destruction wrought by Hurricane Camille on the Gulf coast spurred redevelopment, greatly increasing local property values.[18] Research indicates that the typical hurricane strike raises real house prices for a number of years, with a maximum effect of between 3 percent to 4 percent three years after occurrence.[25] However, disaster response officials point out that redevelopment encourages more people to live in clearly dangerous areas subject to future deadly storms. Hurricane Katrina is the most obvious example, as it devastated the region that had been revitalized after Hurricane Camille. Many former residents and businesses do relocate to inland areas away from the threat of future hurricanes as well.

EFFECTS OF CYCLONES

EFFECTS OF CYCLONES

TRACKS AND AREAS OF CYCLONES• Tropical cyclones are more active in summer . Their

areas of activity is the tropical zone.

• The following are some of the characteristics of the tracks of a cyclones :

• 1. Between the equator and 15°latitude, these storms turn towards the west with the trades.

• 2. Between 15° and 30° latitude the path is very uncertain. But these travel towards the north in the northern hemisphere and the south in the southern hemisphere.

• 3. As these cross 30° latitude they turn towards the east and take much of the character of the temperate cyclone . Their terrific energy also declines.

DIFFERENT NAMES OF CYCLONES IN DIFFERENT COUNTRIES

• The chief areas of activity for the cyclone are the following :• 1. West Indies and the Coast of Florida. In that region these

are known as HURRICANES.• 2. Philippine Islands, the coasts of China and Japan. These

are known as TYPHOONS.• 3. Bay of Bengal and the Arabian Sea, where these are

known as CYCLONES.• 4. Madagascar and the coastal regions of East Africa.• 5. Northeast and Northwestern coasts of Australia, where

they are called WELLY-WELLIES. • They are known as TORNADOES in the U.S.A. and Mexico.

HISTORIC LIST• Tropical cyclones are named for historical reasons and so to avoid confusion when

communicating with the public as more than one tropical cyclone can exist at a time. Names are drawn in order from predetermined lists and are usually assigned to tropical cyclones with one, three or ten minute wind speeds of more than 65 km/h (40 mph). However standards vary from basin to basin with some tropical depressions named in the Western Pacific whilst tropical cyclones have to have gale force winds occurring more than halfway around the center within the Australian and Southern Pacific regions.

• The official practice of naming tropical cyclones started in 1945 within the Western Pacific. Naming continued through the next few years before in 1950, names also started to be assigned to tropical storms forming in the North Atlantic ocean. In the Atlantic, names were originally taken from the world war two version of the Phonetic Alphabet but this was changed in 1953 to use lists of women names which were drawn up yearly. Around this time naming of tropical cyclones also began within the Southern and Central parts of the Pacific. However naming didn't begin the Eastern Pacific until 1960 with the original naming lists designed to be used year after year in sequence. In 1960, naming also began in the Southwest Indian Ocean before in 1963 the Philippine Meteorological Service, started assigning names to tropical cyclones that moved into or formed in their area of responsibility. Later in 1963 warning centers within the Australian region also commenced naming tropical cyclones.

HISTORIC LIST• NORTH ATLANTIC• By 1950 tropical cyclones that were judged by the US Weather Bureau to have intensified into a

tropical storm, started to be assigned names.[1][2] Storms were originally named in alphabetical order using the World War II version of the Phonetic Alphabet.[1] By 1952 a new phonetic alphabet had been developed and this led to confusion as some parties wanted to use the newer phonetic alphabet.[1] In 1953, to alleviate any confusion, forecasters decided to use a set of 23 feminine names.[1][2] After the 1953 Atlantic hurricane season, public reception to the idea seemed favorable, so the same list was adopted for the next year with one change; Gilda for Gail.[1] However after storms like Carol and Hazel got a lot of publicity during the 1953 season, forecasters agreed to develop a new set of names for 1955.[1] However before this could happen, a tropical storm was declared significant on January 2, 1955 and was named as Alice.[1] The new set of names were developed and used in 1955 beginning with Brenda continuing through the alphabet to Zelda.[1] For each season before 1960, a new set of names were developed.[1] In 1960 forecasters decided to begin rotating names in a regular sequence and thus four alphabetical lists were established to be repeated every four years.[3] The sets followed the example of the western Pacific typhoon naming lists and excluded names beginning with the letters Q, U, X, Y and Z.[3] These four lists were used until 1972 when the National Oceanic and Atmospheric Administration (NOAA), replaced them with 9 lists designed to be used from 1972.[3] In 1977, NOAA made the decision to relinquish control over the name selection by allowing a regional committee of the World Meteorological Organization to select the new sets of names which would contain male names and some Spanish and French names in order to reflect all the cultures and languages within the Atlantic Ocean.[2][3] The World Meteorological Organization decided that the new lists of hurricane name would start to be used in 1979.[2][3] Since 1979 the same lists have been used, with names of significant tropical cyclones removed from the lists and replaced with new names.[2] In 2002 Subtropical Cyclones started to be assigned names from the main list of names set up for that year. In 2005 as all the names preselected for the season were exhausted, the contingency plan of using Greek letters for names had to be used.[4] Since then there have been a few attempts to get rid of the Greek names, as they are seen to be inconsistent with the standard naming convention used for tropical cyclones and are considered generally unknown and confusing to the public.[5] However the lists of preselected names for the year, are not expected to be used up frequently enough to warrant any change in the existing naming procedure and thus the Greek Alphabet will be used if the list of pre selected names should ever be used up again.[5][6][7]

HISTORIC LIST

• EASTERN PACIFIC• Within the Eastern Pacific basin between the western coasts of the Americas and 140°W the

naming of tropical cyclones started in 1960, with four lists of female names initially designed to be used consecutively before being repeated.[31][32] In 1965 after two lists of names had been used, it was decided to return to the top of the second list and to start recycling the sets of names on an annual basis.[32][33]

• In 1977, after protests by various women's rights groups, NOAA made the decision to relinquish control over the name selection by allowing a regional committee of the World Meteorological Organization (WMO) to select new sets of names.[3] The WMO selected six lists of names which contained male names and rotated every six years.[3] They also decided that the new lists of hurricane name would start to be used in 1978 which was a year earlier than the Atlantic.[34] Since 1978 the same lists of names have been used, with names of significant tropical cyclones removed from the lists and replaced with new names.[32] As in the Atlantic basin should the names preselected for the season be exhausted, the contingency plan of using Greek letters for names would be used.[32][35] However unlike in the Atlantic basin the contingency plan has never had to be used, although in 1985 to avoid using the contingency plan, the letters X, Y, and Z were added to the lists.[35] Since the contingency plan had to be used in the North Atlantic during 2005 there have been a few attempts to get rid of the Greek names as they are seen to be inconsistent with the standard naming convention used for tropical cyclones and are generally unknown and confusing to the public.[5][6] However none of the attempts have succeeded and thus the Greek letters will be used should the lists be used up.[5][6]

HISTORIC LISTWESTERN NORTH PACIFIC• In the Western North Pacific ocean, there are two sets of names

generally used. The first are the international names assigned to a tropical cyclone by the Japan Meteorological Agency (JMA) or the Joint Typhoon Warning Center (JTWC). The second set of names are local names assigned to a tropical cyclone by the Philippine Atmospheric, Geophysical and Astronomical Services Administration. This system often ends up with a tropical cyclone being assigned two names, should a tropical storm threaten the Philippines.

• On January 1, 2000 the Japan Meteorological Agency as the official Regional Specialized Meteorological Center took over the naming of Tropical storms. The names selected by the World Meteorological Organization's Typhoon Committee were from a pool of names submitted by the various countries that make up the Typhoon Committee.

HISTORIC LIST• CENTRAL NORTH PACIFIC• In 1950 a tropical cyclone that affected Hawaii was named Able, after a tropical

cyclone had not affected Hawaii for a number of years.[40][41] The system subsequently became widely known as Hurricane Hiki, since Hiki is Hawaiian for Able.[40][41] Typhoons Olive and Della of 1952 and 1957 developed within the Central Pacific, but were not named until they had crossed the International Dateline and moved into the Western Pacific basin.[40][42] During 1957, two other tropical cyclones developed in the Central Pacific and were named Kanoa and Nina, by the Hawaiian military meteorological offices.[42] It was subsequently decided that future tropical cyclones, would be named by borrowing names from the Western Pacific naming lists.[42] During 1979, after ten names had been borrowed from the Western Pacific naming lists, Hawaiian names were reinstated for tropical cyclones developing into tropical storms forming in the Central Pacific.[33] Five sets of Hawaiian names, using only the 12 letters of the Hawaiian alphabet, were drafted with the intent being to use the sets of names on an annual rotation basis.[33] However, after no storms had developed in this region between 1979 and 1981, the annual lists were scrapped and replaced with four sets of names and designed to be used consecutively.[33] Ahead of the 2007 hurricane season, the Central Pacific Hurricane Center (CPHC) introduced a revised set of Hawaiian names for the Central Pacific, after they had worked with the University of Hawaii Hawaiian Studies Department to ensure the correct meaning and appropriate historical and cultural use of the names.[43]

HISTORIC LIST

• PHILIPPINES• Since 1963, the Philippine Atmospheric, Geophysical and

Astronomical Services Administration (PAGASA), have assigned their own names to typhoons that pass through its area of responsibility.[45] Unlike the World Meteorological Organization's standard of assigning names to tropical cyclones when they reach wind-speeds of 65 km/h, (40 mph), PAGASA assigns a name to a tropical depression when they either form or move into their area of responsibility.[45][46] Four sets of tropical cyclone names are rotated annually with typhoon names stricken from the list should they do more than 1 billion Pesos worth of damage to the Philippines and/or cause 300 or more deaths.[47][48] Should the list of names for a given year prove insufficient, names are taken from an auxiliary list.[47]

HISTORIC LIST• NORTH INDIAN OCEAN• During its annual session in 2000 the WMO/ESCAP Panel on North Indian tropical cyclones, agreed

in principle to start assigning names to Cyclonic Storms that developed within the North Indian Ocean.[61][62] As a result the panel requested that each member country submit a list of ten names to a rapporteur by the end of the year 2000.[62] At the 2001 session of the Panel, the rapporteur reported that seven of the eight countries had submitted their names.[62] However, India had refused to submit a list of names, as it had some reservations about assigning names to tropical cyclones, due to the regional, cultural and lingustic diverstiy of the panel members.[62] The panel subsquently studied the names and felt that some of the names would not be appealing to the public or the media, and requested that members submit new lists of names.[62] At the following years session the rapporteur reported that there had been a poor response by member countries in resubmitting their lists of names.[62] In response the panel felt that it was important that the work continued and urged the members to copperate and submit their names to the rapporteur.[62] The names were subsquently submitted in time for the 2004 session, however, India had still not submitted their names, despite promising to do so.[62] The rapporteur presented the 4 lists of names that would be used with a gap left for India's names and recommended that the India Meteorological Department's Regional Specialised Meterological Centre in New Delhi name the systems.[62] The rapporteur also recommended that the naming lists were used on an experimental basis during the season, starting in May or June 2004 and that the lists should only be used until 2009 when a new list would be drawn up for the following ten years.[62] The naming lists were then completed in May 2004, after India submitted their names, however the lists were not used until September 2004 when the first tropical cyclone was named Onil by India Meteorological Department.[61][63]

PLANS FOR DETECTION• Because of the forces that affect tropical cyclone tracks, accurate track predictions

depend on determining the position and strength of high- and low-pressure areas, and predicting how those areas will change during the life of a tropical system. The deep layer mean flow, or average wind through the depth of the troposphere, is considered the best tool in determining track direction and speed. If storms are significantly sheared, use of wind speed measurements at a lower altitude, such as at the 70 kPa pressure surface (3,000 metres or 9,800 feet above sea level) will produce better predictions. Tropical forecasters also consider smoothing out short-term wobbles of the storm as it allows them to determine a more accurate long-term trajectory.[107] High-speed computers and sophisticated simulation software allow forecasters to produce computer models that predict tropical cyclone tracks based on the future position and strength of high- and low-pressure systems. Combining forecast models with increased understanding of the forces that act on tropical cyclones, as well as with a wealth of data from Earth-orbiting satellites and other sensors, scientists have increased the accuracy of track forecasts over recent decades.[108] However, scientists are not as skillful at predicting the intensity of tropical cyclones.[109] The lack of improvement in intensity forecasting is attributed to the complexity of tropical systems and an incomplete understanding of factors that affect their development.

MANAGEMENT OF CYCLONES

• Cyclone, tropical cyclone, hurricane, and typhoon are different names for the same phenomenon a cyclonic storm system that forms over the oceans. The deadliest hurricane ever was the 1970 Bhola cyclone; the deadliest Atlantic hurricane was the Great Hurricane of 1780 which devastated Martinique, St. Eustatius and Barbados. Another notable hurricane is Hurricane Katrina which devastated the Gulf Coast of the United States in 2005.

MANAGEMENT OF CYCLONES• An effective disaster management system consists of four main

components — disaster prediction, disaster warning, disaster management and disaster relief. Disaster warning is a basic prerequisite for ensuring disaster preparedness and in some cases to help in the prevention of disaster itself. Clearly the most important application of satellites is in detecting, predicting and delivering early warning of impending disasters such as flood, drought, cyclone and even forest fires (Rao et al. 1987; Heath 1994). Continuous monitoring by both geostationary and low earth orbiting weather satellites like GOES, INSAT, METEOSAT and NOAA is capable of providing early warning on cyclones and floods. Forest fires, environmental hazards, volcanic eruptions and even propagation of desert locust phenomena can be detected well in time by remote sensing satellites like, LANDSAT, SPOT and IRS. Sustainable development strategy must address this important issue in order to provide stability and reasonable security to the vulnerable rural population in these countries. Remote sensing information are now operationally used to regularly monitor flood conditions, volume of water flow and damage assessment. From such a database collected over years, it is possible to identify different risk zones in the flood prone area based on the severity index for flood proneness of each zone. Optimal treatment of each zone on a long term basis, depending on the severity, can then be attempted to achieve reduction in flood damage without impairing environmental integrity (Rao 1993)