Open main menu

In May 2003, a tropical cyclone officially called Very Severe Cyclonic Storm BOB 01[1] produced the worst flooding in Sri Lanka in 56 years. The first storm of the 2003 North Indian Ocean cyclone season, it developed over the Bay of Bengal on May 10. Favorable environmental conditions allowed the system to intensify steadily while moving northwestward. The storm reached peak maximum sustained winds of 140 km/h (85 mph) on May 13, making it a very severe cyclonic storm according to the India Meteorological Department (IMD), which is the official Regional Specialized Meteorological Center for the basin.[2] The cyclone drifted north over the central Bay of Bengal, gradually weakening due to heightened wind shear. Turning eastward, the storm deteriorated to a deep depression on May 16 before it curved northeastward and re-intensified into a cyclonic storm. It came ashore in western Myanmar and dissipated over land the following day.

2003 Sri Lanka cyclone
Very severe cyclonic storm (IMD scale)
Tropical storm (SSHWS)
Tropical Cyclone 01B 2003.jpg
Satellite image of the tropical storm on May 11
FormedMay 10, 2003
DissipatedMay 20, 2003
Highest winds3-minute sustained: 140 km/h (85 mph)
1-minute sustained: 110 km/h (70 mph)
Lowest pressure980 hPa (mbar); 28.94 inHg
Fatalities260 total
Damage$135 million (2003 USD)
Areas affectedSri Lanka, India, Myanmar
Part of the 2003 North Indian Ocean cyclone season

In the wake of prolonged precipitation during the first half of May, the cyclone produced torrential rains across southwest Sri Lanka while stationary in the central Bay of Bengal. The storm drew extensive moisture that coalesced in the mountainous portion of the island. A station at Ratnapura recorded 366.1 mm (14.41 in) of rainfall in 18 hours on May 17, including 99.8 mm (3.93 in) in one hour. In southwestern Sri Lanka, the rainfall caused flooding and landslides that destroyed 24,750 homes and damaged 32,426 others, displacing about 800,000 people. Overall damage totaled about $135 million (2003 USD),[nb 1] and there were 260 deaths. The cyclone also produced some rainfall in the Andaman and Nicobar Islands of India and along the country's eastern coast. The storm funneled moisture away from the mainland, which possibly contributed to a heat wave that killed 1,900 people, and dropped heavy rainfall in Myanmar.

Contents

Meteorological historyEdit

 
Map plotting the track and the intensity of the storm, according to the Saffir–Simpson scale

Around May 6, the monsoon trough extended across the southern Bay of Bengal, producing a vast field of thunderstorm activity.[3] A broad low-pressure area formed by the next day and remained nearly stationary.[3][4] Over the next few days, the convection varied in intensity until becoming more organized around the nascent surface low on May 10.[3] At 03:00 UTC on May 10, the India Meteorological Department (IMD)[nb 2] reported the formation of a depression about 535 km (330 mi) west of Banda Aceh, Indonesia. Within nine hours, the depression further intensified into a deep depression.[4] Around the same time, the system was classified as Tropical Cyclone 01B by the Joint Typhoon Warning Center.[6][nb 3]

With warm sea surface temperatures, a formidable anticyclone aloft,[3] and low wind shear, the system continued to mature as it tracked northwestward.[6] Early on May 11, the deep depression strengthened into a cyclonic storm – marked by maximum sustained winds of at least 65 km/h (40 mph)[nb 4] – and later in the day into a severe cyclonic storm.[4] Simultaneously, the system was driven toward the north by a ridge of high pressure to the northeast.[6] At the time, the cyclone was located about 700 km (430 mi) east of Sri Lanka.[9] The storm continued to intensify, becoming a very severe cyclonic storm on May 12.[4] That day, the JTWC upgraded Tropical Cyclone 01B to the equivalence of a minimal hurricane with winds of 120 km/h (75 mph).[3][nb 5] In post-season analysis, however, the agency revised the storm's maximum winds to 110 km/h (70 mph).[6] At 06:00 UTC on May 13, the IMD estimated that the storm attained peak winds of 140 km/h (85 mph).[11] The intensity estimate was based on a satellite-derived Dvorak number of 4.5, limited chiefly by the lack of an eye feature.[4]

After peaking in intensity, the storm began weakening due to increasing easterly wind shear from the ridge to the north, displacing the center of circulation from the deepest convection.[3][6] Early on May 14, the IMD downgraded the storm to a severe cyclonic storm.[4] Around this time, steering currents slackened, and the cyclone meandered northward over the central Bay of Bengal. By late on May 14, convection had largely dissipated, with the exception of a small area near the center,[3] and the system weakened to minimal cyclonic storm status. Thunderstorm activity continued to wax and wane as the storm turned to the southeastward, though persistent hostile conditions caused the storm to weaken further to a deep depression on May 16. As the nearby ridge translated eastward, the depression was able to move more steadily to the east and later to the northeast, passing northwest of the Andaman Islands on May 18.[3][11] On the next day, the deep depression re-intensified into a cyclonic storm, reaching a secondary peak with winds of 85 km/h (50 mph).[4][11] At about 10:00 UTC on May 19, the storm made landfall close to Kyaukpyu, Ramree Island, in western Myanmar.[3][6] The storm rapidly weakened into a depression and later degenerated into a low pressure area on May 20,[4] and was no longer discernible on satellite imagery by the next day.[3]

Preparations and impactEdit

Sri LankaEdit

 
Location map of Sri Lanka

Due to the significant distance between Sri Lanka and the Bay of Bengal storm, no cyclone warnings were posted. The India-based National Centre for Medium Range Weather Forecasting anticipated the flood event three days in advance.[12] However, the Sri Lankan government did not issue the first flood warnings until May 17, the same day that the flooding began. Many residents learned about the impending floods through loudspeakers and word of mouth, although some were alerted by television or radio. About 8,000 people evacuated on May 18, utilizing schools and public buildings as emergency shelters. The precipitation occurred in the wake of an already rainy period; a station near the Kalu River reported over 600 mm (24 in) of rainfall in the first 15 days of May.[13]

While the storm was nearly stationary in the central Bay of Bengal, the southwesterly flow drew abundant moisture over Sri Lanka to produce severe flooding. In the island's mountainous southwestern portion, the winds across the island produced heavy rainfall rates through a process known as orographic lift, mostly occurring on May 17–18. Throughout May 2003, the highest rainfall in the country was 899 mm (35.4 in) at Gonapenigala Iranganie Estate. A station at Ratnapura recorded 718 mm (28.3 in) of precipitation in the month,[9] of which 366.1 mm (14.41 in) fell over an 18‑hour period on May 17; at the same station, there was a peak hourly rainfall total of 99.8 mm (3.93 in).[13] These were the heaviest rains on the island since 1947.[14] Rainfall was primarily concentrated in southwestern Sri Lanka, with a rain shadow farther inland that resulted in minimal precipitation in and Matale.[9] After the Kalu River overflowed, floodwaters reached 3 m (9.8 ft) deep in Ratnapura City, submerging the first floors of most homes and persisting for about three days. Landslides created a temporary natural dam on the river that washed away a bridge when it broke. Along the Gin River, flood waters inundated the surrounding terrain up to 2 m (6.6 ft) deep, covered roadways, and complicated evacuations.[13] In Hambantota District, the inundation occurred after an ongoing drought, which amplified flood-related damage.[15] Although the flooding was severe in the southwestern portion of Sri Lanka, effects were minimal in the central and north-central regions, and there was no severe flooding in the capital city of Colombo.[16]

Since the previously wet conditions had saturated soils,[13] the rains related to the cyclone caused severe flooding and landslides, mostly in Ratnapura and Nuwara Eliya districts.[17][18] A landslide in Batugoda killed 81 people,[19] and at least 125 people died in Ratnapura.[20] The floods increased river levels in Hambantota, Matara, Galle, and Kalutara districts, persisting until May 30 in Matara.[18] Many roads were damaged, including the one that links Ratnapura to Colombo.[14] About 100 schools were destroyed and another 200 were damaged,[21] and some health facilities lost their equipment.[22] Flooding from the cyclone destroyed 53,300 hectares (132,000 acres) of tea crops,[18] representing an estimated 20–30% loss for the year in the low country.[12] Farmers in the affected areas also lost some of their rice paddies to the high waters,[16] although only about 3% of the rice crop in the region was damaged, so no impact on the rice harvest was expected.[23] Many areas lost electricity and telephone service,[15] and there were disruptions to food and water supplies.[24]

Throughout Sri Lanka, the floods destroyed at least 24,750 homes and damaged 32,426 others,[21] displacing about 800,000 people,[25] many of whom lost everything they owned.[26] Total damage was estimated at $135 million (2003 USD),[27] primarily to homes and roads.[13] Across the island, floods related to the cyclone killed 260 people.[12] Most of the deaths were along the nation's southern coast where the floods occurred, primarily along the Kalu River, and were mainly farmers. Levees helped drain floodwaters where systems were already in place.[13]

ElsewhereEdit

In its formative stages, the storm produced moderate rainfall in the Andaman and Nicobar Islands, totaling 70 mm (2.8 in) at Mayabunder. Later, as the storm was approaching Myanmar, it dropped 89 mm (3.5 in) of rainfall on Hut Bay.[4] Several stations in Tamil Nadu reported light precipitation, including a total of 98 mm (3.9 in) at Adirampattinam.[3] Along the coast of Odisha, the fringes of the cyclonic storm dropped light rainfall, reaching 53 mm (2.1 in) at Swampatna.[4] As the storm made landfall in Myanmar, it produced heavy rainfall in Rakhine State, signalling an early start to the monsoon season.[28]

The slow movement of the storm altered the atmospheric flow over southeastern India. According to the IMD, the cyclone "might have caused the severe heat wave conditions prevailing over the coastal Andhra Pradesh" from May into early June, killing up to 1,400 people,[4] and increasing air temperatures to 50 °C (122 °F).[29]

AftermathEdit

 
Satellite-derived precipitation rates related to the storm from May 15–19; Sri Lanka is in the bottom center with the highest totals in a dark shade of red

In the immediate aftermath of the flooding in Sri Lanka, the country's air force, army, and navy, as well as police forces, operated search and rescue missions. The navy and air force collected residents stranded in trees and on roofs,[16] and were later assisted by the Indian military.[24] However, the lack of electricity and the damaged infrastructure hampered relief work.[30] In the hardest hit area of Ratnapura, there was a shortage of doctors, prompting officials to request help from adjacent towns.[16] There were increased reports of diarrhea, viral flu, and typhoid in the aftermath of the floods.[25] Mobile health crews treated over 44,000 residents, which helped reduce the spread of disease.[26] Residents in one village went without food for three days, and in the storm's aftermath, many were also without access to clean water.[31] By May 19, flooding had begun to recede in the worst affected areas, allowing workers to repair roads.[14] The government released RS6 million (LKR, US$62,500) for immediate relief, and also provided RS15,000 (LKR, US$156) toward funeral expenses for each death.[14] From May 22–25, the country's legislature had reduced sessions so members could return to their districts.[32] By the end of May 2003, the government had allocated RS17.29 million (LKR, US$180,000) for relief measures,[25] including RS27,000 (LKR US$280) for each family to rebuild houses.[33] The Sri Lankan government also set up a four-person task force to manage flood relief.[14] The local Red Cross chapter utilized emergency supplies to distribute 10,000 food packages while also deploying trained volunteers to assist in the disaster areas.[15] The Red Cross ultimately distributed about 26,000 loaves of bread, 862 kg (1,900 lb) of sugar, and 1,775 kg (3,913 lb) of rice, among other supplies.[26] By May 20, the Sri Lankan air force had distributed 35 tons of food, using eight helicopters to airdrop parcels.[24] Red Cross workers cleaned hundreds of contaminated wells in the region, thereby restoring clean water access;[34] this task was finished by August.[35] By May 16, or nine days after the floods began, power was restored to about 95% of areas, and roads were gradually rebuilt.[36] Road access to most villages was restored by May 26, with the exception of Matara. There, the ongoing floods prompted officials to close schools to reduce the spread of disease.[33] After the floods largely subsided, the World Socialist Web Site criticized the Sri Lankan government for not having better disaster management in place, as well as noting that deforestation and gem mining contributed to the landslides.[25] A Red Cross report in August 2003 noted the swift work to bring relief to the affected citizens, while also commenting that the floods displayed the country's problems with disaster mitigation.[35]

On May 19, the Red Cross launched an appeal to the international community for assistance.[14] A day prior, the Red Cross allocated CHF50,000 to buy relief supplies, while the United Nations Office for the Coordination of Humanitarian Affairs provided a $50,000 grant.[19] In the days after the floods, the government of India sent a ship with inflatable dinghies and medical supplies.[16] A total of 18 countries or local Red Crosses sent Fr.2.3 million CHF worth of cash to Sri Lanka.[35] Sweden sent kr800,000 (2003 SEK) toward relief transport and distribution.[31] The government of Japan sent ¥19.8 million yen worth of tents, sheets, and other supplies to the country,[37] The Iranian Red Cross sent $65,625 (USD) worth of blankets and tents to Sri Lanka,[38] which helped about 240 families.[35] Australia's government sent about $400,000 (AUD) to UNICEF to help rebuild the damaged schools and other social services.[39] The European Community Humanitarian Aid Office donated about €800,000 (US$944,000) to the country.[33] The World Food Programme distributed meals to about 10,000 families, while the World Health Organization provided water purification tablets, typhoid vaccines, and health kits to about 100,000 people.[40] During a peace agreement amid the ongoing civil war, the Tamil Tigers in Sri Lanka sent trucks with clothing and food to the affected areas.[41] In July 2004, the Asian Development Bank provided $12.5 million of the $17.5 million needed to repair the damaged infrastructure, while the Sri Lankan government provided the remaining $5 million.[42]

See alsoEdit

NotesEdit

  1. ^ All currencies are in 2003 values of their respective currencies.
  2. ^ The India Meteorological Department is the official Regional Specialized Meteorological Center for the northern Indian Ocean.[5]
  3. ^ The Joint Typhoon Warning Center is a joint United States Navy – United States Air Force task force that issues tropical cyclone warnings for the northern Indian Ocean and other regions.[7]
  4. ^ The IMD gauges winds over a three-minute average.[8]
  5. ^ The JTWC gauges winds over a one-minute average.[10]

ReferencesEdit

  1. ^ Best Tracks Data (1990 - 2013) (Report). India Meteorological Department. Archived from the original on 2014-09-25. Retrieved 2014-04-29.CS1 maint: BOT: original-url status unknown (link)
  2. ^ Worldwide Tropical Cyclone Centers (Report). National Hurricane Center. 2011-09-11. Retrieved 2012-08-27.
  3. ^ a b c d e f g h i j k John Wallace (2003). "Monthly Global Tropical Cyclone Summary May 2003". Gary Padgett. Retrieved 2014-04-19.
  4. ^ a b c d e f g h i j k N. Jayanthi; A. B. Mazumdar; S. Sunitha Devi (July 2004). "Cyclones and depressions over north Indian Ocean during 2003" (PDF). MAUSAM. 55 (3). Retrieved 2014-04-19.
  5. ^ RSMC New Delhi. Regional Specialised Meteorological Centre (RSMC) - Tropical Cyclones, New Delhi (PDF) (Report). India Meteorological Department. Archived from the original on 2014-09-04. Retrieved 2015-04-24.CS1 maint: BOT: original-url status unknown (link)
  6. ^ a b c d e f Tropical Cyclone (TC) 1B (PDF) (Report). Joint Typhoon Warning Center. Retrieved 2014-04-19.
  7. ^ Joint Typhoon Warning Center (2011). "Joint Typhoon Warning Center Mission Statement". United States Navy, United States Airforce. Archived from the original on 2007-07-26. Retrieved 2011-11-30.
  8. ^ "Frequently Asked Questions on Tropical Cyclones". India Meteorological Department. Archived from the original on 2015-05-21. Retrieved 2015-04-24.
  9. ^ a b c Lareef Zubair; Upamala Tcnnakonc; Zcenas Yahiya; Janaki Chandimala; M.R.A. Siraj. "What led to the May 2003 Floods?" (PDF). Journal of the Institute of Engineers, Sri Lanka. 36 (3): 51–52. Retrieved 2014-04-21.
  10. ^ "Frequently Asked Questions". Joint Typhoon Warning Center. 2012-08-13. Retrieved 2015-04-24.
  11. ^ a b c Kenneth R. Knapp; Michael C. Kruk; David H. Levinson; Howard J. Diamond; Charles J. Neumann (2010). The International Best Track Archive for Climate Stewardship (IBTrACS): Unifying tropical cyclone best track data: 2003 Missing (2003129N05091). Bulletin of the American Meteorological Society (Report). Archived from the original on 2016-03-05. Retrieved 2014-10-20.
  12. ^ a b c Lareef Zubair (2004). "May 2003 Disaster in Sri Lanka and Cyclone 01-B in the Bay of Bengal" (PDF). Natural Hazards. 33 (3). doi:10.1023/b:nhaz.0000048462.21938.d6. Retrieved 2014-04-25.
  13. ^ a b c d e f Junichi Yoshitani; Norimichi Takemoto; Tarek Merabtene (2007). Factor Analysis of Water-related Disasters in Sri Lanka (PDF). The International Centre for Water Hazard and Risk Management (Report). Public Works Research Institute. pp. 52, 57, 59–61, 67, 103, 111. ISSN 0386-5878. Retrieved 2014-04-28.
  14. ^ a b c d e f Sri Lanka: Flooding & landslides Information Bulletin No. 2 (Report). International Federation of Red Cross and Red Crescent Societies. 2003-05-19. Retrieved 2014-04-25 – via ReliefWeb.
  15. ^ a b c Sri Lanka: Flooding & landslides Information Bulletin No. 1 (Report). International Federation of Red Cross And Red Crescent Societies. 2003-05-19. Retrieved 2014-04-25 – via ReliefWeb.
  16. ^ a b c d e Amal Jayasinghe (2003-05-18). "India sends navy ship to help as Sri Lanka flood toll near 150". Agence France-Presse. Retrieved 2014-04-23 – via ReliefWeb.
  17. ^ WMO Statement on the Status of the Global Climate in 2003 (PDF) (Report). World Meteorological Organization. 2004. p. 11. Archived from the original (PDF) on 2012-05-08. Retrieved 2014-04-21.
  18. ^ a b c "2003 Flood Archive". Dartmouth Flood Observatory. Retrieved 2014-04-21.
  19. ^ a b Sri Lanka - Floods OCHA Situation Report No. 1 (Report). United Nations Office for the Coordination of Humanitarian Affairs. 2003-05-18. Retrieved 2014-04-22 – via ReliefWeb.
  20. ^ Scott McDonald (2003-05-21). "Hundreds still missing from Sri Lanka floods". Reuters. Retrieved 2014-04-28 – via ReliefWeb.
  21. ^ a b "Sri Lanka pours more troops to boost flood relief". Agence France-Presse. 2003-05-23. Retrieved 2014-04-28 – via ReliefWeb.
  22. ^ Floods ravage Sri Lanka (Report). Plan. 2003-05-23. Retrieved 2014-04-28 – via ReliefWeb.
  23. ^ Sri Lanka: Flooding and Landslides Emergency Appeal No. 13/03 Operations Update no. 3 (Report). International Federation of Red Cross And Red Crescent Societies. 2003-06-12. Retrieved 2014-04-29 – via ReliefWeb.
  24. ^ a b c "Sri Lanka banks on foreign help as flood death toll hits 242". Agence France-Presse. 2003-05-20. Retrieved 2014-04-25 – via ReliefWeb.
  25. ^ a b c d "Nearly one million left homeless by Sri Lankan floods". World Socialist Web Site. International Committee of the Fourth International. 2003-05-27. Retrieved 2014-04-25.
  26. ^ a b c Sri Lanka: Flooding and Landslides Emergency Appeal No. 13/03 Operations Update no. 2 (Report). International Federation of Red Cross and Red Crescent Societies. 2014-04-29. Retrieved 2003-05-30 – via ReliefWeb.
  27. ^ Thirty-First Session Final Report (PDF) (Report). WMO/ESCAP Panel on Tropical Cyclones. United Nations Office for Disaster Risk Reduction. 2004. Archived (PDF) from the original on 2014-05-03. Retrieved 2014-05-03.
  28. ^ Myo Theingi Cho (2003-06-01). "Cyclone brings an early monsoon". Myanmar Times. 9 (167). Archived from the original on 2014-05-02. Retrieved 2014-04-29.
  29. ^ "Indian heat wave claims almost 2,000 lives". International Federation of Red Cross and Red Crescent Societies. 2003-06-12. Retrieved 2014-04-21 – via ReliefWeb.
  30. ^ Floods kill 200 in Sri Lanka (Report). World Vision. 2003-05-20. Retrieved 2014-04-25 – via ReliefWeb.
  31. ^ a b Sri Lanka: Flooding and Landslides Emergency Appeal No. 13/03 Operations Update no. 1 (Report). International Federation of Red Cross And Red Crescent Societies. 2003-05-23. Retrieved 2014-04-28 – via ReliefWeb.
  32. ^ "Indian military joins Sri Lanka relief effort after flood havoc". Agence France-Presse. 2003-05-20. Retrieved 2014-04-25 – via ReliefWeb.
  33. ^ a b c Sri Lanka - Floods OCHA Situation Report No. 4 (Report). United Nations Office for the Coordination of Humanitarian Affairs. 2003-05-26. Retrieved 2014-04-29 – via ReliefWeb.
  34. ^ Red Cross takes lead in clean water for Sri Lanka flood victims (Report). International Federation of Red Cross and Red Crescent Societies. 2003-05-28. Retrieved 2014-04-29 – via ReliefWeb.
  35. ^ a b c d Sri Lanka Floods and Landslides - Appeal No. 13/03; Operations Update no. 4 (PDF) (Report). 2003-08-29. Retrieved 2015-03-26 – via ReliefWeb.
  36. ^ "Sri Lanka puts flood toll at 254, seeks foreign help". Agence France-Presse. 2003-06-03. Retrieved 2014-04-29.
  37. ^ Emergency aid for flood disaster in Sri Lanka (Report). Government of Japan. 2003-05-21. Retrieved 2014-04-28 – via ReliefWeb.
  38. ^ Red Crescent relief aids to Algeria and Sri Lanka (Report). Iranian Red Crescent. 2003-05-31. Retrieved 2014-04-25 – via ReliefWeb.
  39. ^ Australia to help restore schools destroyed by floods in Sri Lanka (Report). Government of Australia. 2003-05-27. Retrieved 2014-04-28 – via ReliefWeb.
  40. ^ UN mounts system-wide response to help Sri Lanka cope with deadly monsoon. UN News Service. 2003-05-21. Retrieved 2014-04-28 – via ReliefWeb.
  41. ^ "Tigers join Sri Lankan flood relief drive". Agence France-Presse. 2003-05-21. Retrieved 2014-04-28 – via ReliefWeb.
  42. ^ ADB grants emergency assistance for flood-affected districts in southern Sri Lanka (Report). Asian Development Bank. 2004-07-09. Retrieved 2014-04-29 – via ReliefWeb.