Successfully reported this slideshow.
Your SlideShare is downloading. ×



Check these out next

1 of 25 Ad

More Related Content

Recently uploaded (20)



  1. 1. CYCLONE DISASTER MANAGEMENT Dr Fayaz A. Malla Assistant Professor, Environmental Sciences GDC Pulwama Higher Education Department, Govt. of J&K Email:
  2. 2. Definition • A cyclone is a large scale air mass that rotates around a strong center of low atmospheric pressure. • They are usually characterized by inward spiraling winds that rotate clockwise and anti-clockwise. • A tornado is rotating column of air whirling at destructively high speeds, usually accompanied by a funnel-shaped downward extension of a thundercloud.
  3. 3. Geographical Location Cyclones begin in tropical regions such as Pacific islands, Northern Australia and other areas. Tornadoes have been spotted in all continents except Antarctica. Highest frequencies occur in the Netherlands, and up to 1200 on average in the United States.
  4. 4. Characteristics • Cyclones have a low pressure center which is called the "eye", and the wind circling around is counter clockwise on the northern hemisphere and clockwise in the southern hemisphere. • The speed of cyclones varies from 32 to 200 kmph. • Cyclone mainly occur in a particular season and mainly affect the coastal areas. • Cyclones can be of three main types:  Polar  Tropical  Mesocyclones 6
  5. 5. • Tornadoes normally rotate cyclonically (when viewed from above, this is • counterclockwise in the northern hemisphere and clockwise in the • southern). • The speed of tornado varies from 60 to 480 kmph. • Tornadoes are most common in spring and least common in winter. • Tornadoes can be of three main types:  Multiple vortex  Waterspout  Landspout Tornado
  6. 6. Intensity and Damage • The scale for measuring cyclones is called the Beaufort Scale and Saffir-Simpson scale and may vary in different countries. • The scale for measuring the intensity of cyclones depends on the intensity of damage and the wind speed. • The scale ranges from negligible house damage, and destruction of plants and tress to extensive damage and widespread destruction, with wind speed ranging from 74 to 156 mph.
  7. 7. • The intensity of tornadoes can also vary in intensity those with a longer track being stronger. The scale used for rating the strength of tornadoes is called the Fujita (F), Enhanced Fujita (EF), and TORRO (T) Scale. • The range varies from F0, EF0 or T0 for minimal damage (damages trees but not buildings) up to F5, EF5 or T11 for vast degree of damage (buildings and skyscrapers end up getting damaged). • In the United States, maximum tornadoes (80%) fall into the EF0 and EF1 (T0 to T3) category and less than 1% are violent (EF4, T8 or more). Tornado
  8. 8. Detection Cyclones and tornadoes are detected by Pulse Doppler radar, photogrametry, and ground swirl patterns.
  9. 9. Photos Cyclone Tornado Source: Cyclone Nilofar URL: Source: This was part of the Oklahoma tornado outbreak on May 3, 1999 URL:
  10. 10. Comparison
  11. 11. PROTECTION AGAINST CYCLONE Four Stage Warning
  12. 12. • Extreme Weather Events • Causes major loss of lives and live stocks. • In single event 2 to 3 lakh people lost lives. (Bangladesh Cyclone, November 1970.) • Only weather system which bears name or identification because of long life. Eye Eye-wall Convective cells Spiral cloud bands TROPICAL CYCLONE Low pressure system Low (<17 knot) Depression (17-27) Deep Depression (28-33) Cyclone (34-47) Severe Cyclone (48-63) Very Severe Cyclone (64-119) Super Cyclone (12 and above)
  14. 14. NORTH INDIAN OCEAN • Bay of Bengal is a vast warm pool adjoining the warm pool of the western North Pacific. Several of the precursors of the Bay of Bengal cyclones emerge from the neighboring Pacific basin as remnant of typhoons and re-intensify over the Bay after passing over rather narrow strip of SE Asian countries • Ocean currents in the Bay of Bengal are quite complex and in the post- monsoon season low salinity warm waters begin to cover eastern coastal waters from October to December through the East India Coastal Current
  15. 15. State Total No. West Bengal 69 Orissa 98 Andhra Pradesh 79 Tamil Nadu 62 Karnatka 02 Maharashtra & Goa 18 Gujarat 28 Kerala 03
  16. 16. PAST STUDIES
  17. 17. Probable Maximum Storm Surge in meters for each coastal District A shallower bathymetry piles up the surge more Source: IMD
  18. 18. Category : Cyclonic storm T Number : T2.5 Wind speed : 34-47 Knots 62-87 Kmph Structures : Damage to thatched huts Communication and power: Minor damage to power and communication lines due to breaking of tree branches. Road/Rail : Major damage to Kutcha and minor damage to Pucca roads. Agriculture : Some damage to paddy crops, Banana, Papaya trees and orchards. Marine Interests : High to very high sea waves about 6-9 m high. Coastal Zone : Sea water inundation in low lying areas after erosion of Kutcha embankments Overall Damage Category : Minor to Moderate Impact of Cyclonic Storms
  19. 19. Category : Severe Cyclonic storm , T Number : T3.5 Wind speed : 48-63 Knots (88-117 Kmph) Structures : Major damage to thatched houses / huts. Roof tops may blow off. Unattached metal sheets may fly. Communication and power: Minor damage to power and communication lines. Road/Rail : Major damage to Kutcha and some damage to Pucca roads. Flooding of escape routes. Agriculture : Breaking of tree branches, uprooting of large avenue trees. Moderate damage to Banana and Papaya trees. Large dead limbs blown from trees. Marine Interests : Phenomenal seas with wave height 9-14 m. Movement in motor boats unsafe. Coastal Zone : Major damage to coastal crops. Storm surge upto 1.5m (area specific) causing damage to embankments/ salt pans. Inundation upto 5 Km in specific areas. Overall Damage Category : Moderate Impact of Cyclonic Storms
  20. 20. Category : Very Severe Cyclonic storm , T Number : T4.0 – 4.5 Wind speed : 64-90 Knots (118-167 Kmph) Structures : Total destruction of thatched houses/ extensive damage to Kutcha houses. Some damage to Pucca houses. Potential threat from flying objects. Communication and power: Bending/uprooting of power and commn poles. Road/Rail : Major damage to Kutcha and Pucca roads. Flooding of escape routes. Minor disruption of railways, overhead power lines and signaling systems. Agriculture :Widespread damage to standing crops plantations, orchards, falling of green coconuts and tearing of palm fronds Blowing down bushy trees like mango. Marine Interests : Phenomenal seas with wave heights more than 14m. Visibility severely affected. Movement in motor boats and small ships unsafe. Coastal Zone : Storm surge up to 2 m, Inundation up to 10 Km in specific areas. Small boats, country crafts may get detached from moorings. Overall Damage Category : Large Impact of Cyclonic Storms
  21. 21. Category : Very Severe Cyclonic storm , T Number : T5.0 – 6.0 Wind speed : 91-119 Knots (168-221 Kmph) Structures : Extensive damage to all types Kutcha houses, some damage to old badly managed Pucca structures. Potential threat from flying objects. Communication and power: Extensive uprooting of power and communication poles. Road/Rail : Disruption of rail / road link at several places. Agriculture :Extensive damage to standing crops plantations, orchards. Blowing down of Palm and Coconut trees. Uprooting of large bushy trees. Marine Interests : Phenomenal seas with wave heights more than 14m. Movement in motor boats and small ships not advisable. Coastal Zone : Storm surge up to 2 – 5 m, Inundation may extend up to 10- 15 Km over specific areas. Large boats and ships may get torn from their moorings, country crafts may get detached from moorings Overall Damage Category :Extensive Impact of Cyclonic Storms
  22. 22. Category : Super Cyclonic storm , T Number : T 6.5 and above Wind speed : 120 Knots and above (222 Kmph and above) Structures :Extensive damage to non concrete residential &industrial building. Structural damage to concrete structures. Air full of large projectiles. Communication and power: Uprooting of power and communication poles. Total disruption of communication and power supply. Road/Rail : Extensive damage to Kutcha roads and some damage to poorly repaired pucca roads. Large scale submerging of coastal roads due to flooding and sea water inundation. Total disruption of railway and road traffic due to major damages to bridges, signals and railway tracks. Washing away of rail / road links at several places. Agriculture :Total destruction of standing crops/orchards, uprooting of large trees & blowing away of palm and coconut crowns, stripping of tree barks. Marine Interests : Phenomenal seas with wave heights more than 14m. All shipping activity unsafe. Coastal Zone : Extensive damage to port installations. Storm surge more than 5m, Inundation up to 40 Km in specific areas and extensive beach erosion. All ships torn from their moorings. Flooding of escape routes. Overall Damage Category :Catastrophic Impact of Cyclonic Storms
  23. 23. Classification of Cyclone Prone Districts  All coastal districts are cyclone prone.  Therefore, it become imperative to decide degree of proneness.  In general, coastal districts in WB, Orissa, AP & TN are in high to very high category.  Some interior districts in NE India(earlier included in BMTPC atlas) excluded.  Cyclone proneness is very high for the districts of south 24 praganas & Midnapore (West Bengal), Balasore, Kendrapara, Bhadrak, Jagatsinghpur & Ganjam (Orissa), Nellore, Guntur, east Godabari (Andhra Pradesh)
  24. 24. Cyclone Operation in India • Meteorological Department, by providing Cyclone Surveillance Radars at Calcuta in the east coast and at Goa, Bombay in the west coast. • Satellite picture receiving equipments at Delhi, Bombay, Madras are receiving satellite pictures of the cyclones from the polar-orbiting Satellites of the U.S.A. and U.S.S.R. Since April 1982. • A.V.H.R.R. (Advance very High Resolution Radio-meter) Indian Geo Stationary Satellite INSAT-LB has become operational since October 1983. • Monitoring of the cyclone by taking hourly pictures has helped the forecaster to improve his skill in issuing the timely warnings to the public. SOME INDIAN ASSOCITIONS • Area Cyclone Warning Centres (ACWC) • Cyclone Warning Centres (CWC) • Numerical Weather Prediction (NWP) • Northern Hemispheric Analysis Centre (NHAC) • Cyclone Warning Research Centre (CWRC) • Regional Specialized Meteorological Centre