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Objectives

UN-ECLAC Disaster Assessment Methodology The Coastal Zone: Summary of Caribbean Risks, Hazards and Vulnerabilities. Objectives. Primary objectives of this session are:

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Objectives

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  1. UN-ECLAC Disaster Assessment MethodologyThe Coastal Zone: Summary of Caribbean Risks, Hazards and Vulnerabilities

  2. Objectives Primary objectives of this session are: To familiarize the user with the various hazards that can affect the Caribbean region in general, while giving an indication of country specific occurrences of disaster. · To provide some indication of the consequences of these hazards, their frequencies of occurrence and historic patterns of impact. ·To develop a better understanding of the mechanisms of these hazards. ·To set the stage for the necessary reconstruction mechanisms and for mitigation of future damage. ECLAC Disaster Assessment Methodology

  3. Profile of the Caribbean & Coastal Areas • Can be divided into Greater Antilles/Lesser Antilles – based on location and geological origin • All are islands with high coastline to area ratios, and are therefore particularly vulnerable to coastal hazards. • Apparently differing levels of risk between Windward and Leeward Islands ECLAC Disaster Assessment Methodology

  4. Coastal Hazards in the Caribbean • Over 6000 lives lost in the Caribbean over past 30 years due to natural disasters. • Greater Antilles • (Cuba, Jamaica, Hispañola, Puerto Rico) • Hurricanes • Floods • Earthquakes • Lesser Antilles • (St. Maarten to Trinidad) • Hurricanes • Volcanic Eruptions (Ash fallout) • Earthquakes • Tsunamis ECLAC Disaster Assessment Methodology

  5. Coastal Hazards in the Caribbean (cont’d) ECLAC Disaster Assessment Methodology

  6. Hurricanes: A Primary Source of Risk to Caribbean Coastal Infrastructure

  7. Damage from Hurricanes Occurs primarily from: • Hurricane waves; • Beach scour and; • Storm surge. ECLAC Disaster Assessment Methodology

  8. Hurricane Waves • Deep water waves resulting from hurricanes can be very damaging. Estimates of extreme (I.e. design) wave heights made throughout the region are summarized following: Port Zante, St. Kitts ECLAC Disaster Assessment Methodology

  9. Hurricane Waves (cont’d) These deep water waves change in height as they travel in to shallower water. These changes result from interactions between the waves and the seabed, other waves and wind inputs. At the shoreline, they can be very damaging, breaking out infrastructure and eroding shorelines. West coast, Grenada ECLAC Disaster Assessment Methodology

  10. Beach Scour • During a storm event, the extreme wave energy often results in severe erosion of the beach and/or shoreline. • This erosion may reach up to 20-30 m inland, depending on the storm severity, and can totally wipe out beach areas and adjacent infrastructure. West coast, St. Lucia ECLAC Disaster Assessment Methodology

  11. Beach Scour • The erosion is exacerbated where there are buildings (i.e. vertical walls) in the wave run-up zone. • Shore protection methods must be carefully designed so as not to negatively impact adjacent shoreline areas. After Hurricane Lenny ECLAC Disaster Assessment Methodology

  12. Components of Storm Surge ECLAC Disaster Assessment Methodology

  13. Components of Storm Surge ECLAC Disaster Assessment Methodology

  14. Example of Storm Surge High storm waves Inundation of waterfront promenade, Dominica ECLAC Disaster Assessment Methodology

  15. Hurricanes in the Caribbean: Historical Account • Records of hurricane damage exist in the archives of the Caribbean for over five centuries; • Since approximately 1900, detailed hurricane records and characteristics have been maintained by the National Hurricane Center (NHC) and NOAA in Florida, USA. These records have improved in accuracy and detail since the 1950’s, first with the ability of special reconnaissance aircraft to fly into the eye of these storms, and later, with the aid of satellite imagery. ECLAC Disaster Assessment Methodology

  16. Hurricanes in the Caribbean • The records over the past century show a wide band of hurricane activity across the Caribbean, with the least activity occurring in the area of Trinidad; • In general, damage has occurred from storm surge, waves, wind and rainfall, as all of the islands have vulnerable aspects to them; • Latest research indicates climate change impacts. ECLAC Disaster Assessment Methodology

  17. Hurricanes passing close to Jamaica 1980-1999 ECLAC Disaster Assessment Methodology

  18. Flooding: A source of risk to coastal property and productivity • Over 1300 lives lost to flooding in Caribbean over last 20 years ECLAC Disaster Assessment Methodology

  19. Flooding in the Caribbean: Historical Account • In the Lesser Antilles, flooding has been associated primarily with tropical waves or hurricanes; • Flooding may take the form of excessive ponding, as occurred in Antigua in Antigua during Hurricane Lenny, or flash flooding as can occur in the more hilly or mountainous islands such as Nevis and Dominica; • In general, all of the islands and their communities are vulnerable to flooding and drainage systems need to be designed to take this into account. ECLAC Disaster Assessment Methodology

  20. Flood Consequences in Jamaica • Eroded river beds and cut-off roads. • Damaged bridges • Slope stability problems. • Landslides and mudslides. ECLAC Disaster Assessment Methodology

  21. Earthquakes: A source of risk to property and life The Modified Mercalli Scale ECLAC Disaster Assessment Methodology

  22. Earthquakes and Volcanoes in the Caribbean The Caribbean Region, Central and South America are characterized by a belt of seismicity. This is depicted here, with volcanic epicentres shown as green triangles and earthquake epicenters shown as orange dots. ECLAC Disaster Assessment Methodology

  23. Earthquakes in the Caribbean • Major Earthquakes • Jamaica (1692) • Trinidad (1766) • Antigua (1843) • Minor Events • St. Lucia (1953) • Trinidad (1954) • Antigua (1974) ECLAC Disaster Assessment Methodology

  24. Volcanoes: A source of risk to property and life A significant Hazard in the Lesser Antilles • Soufriere (1718, 812, 1902-3, 1979) • Mt. Pelee (1902, 1929-32) • Soufriere Hills (1997) ECLAC Disaster Assessment Methodology

  25. Soufriere Hills, Montserrat ECLAC Disaster Assessment Methodology

  26. Plymouth, Montserrat ECLAC Disaster Assessment Methodology

  27. Volcanoes in the Caribbean: Historical Account • 17 Volcanoes erupted in the Eastern Caribbean. • 25 Volcanic Centres with the potential to erupt. • Approx. 40,000 lives lost in 1902 eruptions (St. Vincent and Martinique). • Warning time has ranged from 14 days to 14 years. • The famous Port Royal disaster of 1692 was initially caused by an earthquake which liquefied an alluvial plane causing it to slide into the sea, the resulting tsunami was several metres in height and caused over 2000 deaths. ECLAC Disaster Assessment Methodology

  28. Tsunamis: another source of risk • More a problem in the Lesser Antilles • Caused by ocean centred earthquakes, or volcanic eruptions. • Greatest risk presently posed by “Kick ‘em Jenny” SeaBeam image of Kick 'em Jenny constructed from measurements taken from the NOAA Research Vessel Ronald H. Brown on March 12 2002. ECLAC Disaster Assessment Methodology

  29. Tsunamis in the Caribbean: Historical Account ECLAC Disaster Assessment Methodology

  30. Tsunami Risk Zones ECLAC Disaster Assessment Methodology

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