BARBADOS

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BARBADOS

• BASIC FACTS
• AREA- 170Sq Mls
• POPULATION- 255,000 (1990)
• GEOLOGY- Limestone, Impermeable Sandstone,
  Shale, Marl
• TOPOGRAPHY- Undulating to max. of 1100 ft
  approximately
• RAINFALL- Average of 45 - 60 ins per year
• 
  

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NATURAL HAZARDS

• HURRICANE- Threatens all exposed structures
  including houses, commercial and public
  buildings, telecommunications towers, utilities,
  agriculture.
• STORM SURGE Hurricane related. Threatens most of
  the coastline especially the economically vital
  tourism plant and some critical lifeline
  facilities.

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NATURAL HAZARDS

• TSUNAMI- A threat to most of the coastal area
  outlined for Storm Surge.
• LAND BORNE FLOODING- Occurs in several areas
  across the island.
• LANDSLIDES- Concentrated mainly in the Scotland
  District. Covers 1/7 of the island. Consists
  mainly of impermeable sandstone, shale, marl.

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HAZARD / NATURAL REOURCES STUDIES

• SCOTLAND DISTRICT ( 6 STUDIES 1946 - 97)
• STORM WATER DRAINAGE STUDIES (73, 94)
• ENVIRONMENTAL AND NATURAL RESOURCES STUDY/PLAN
  (1998)
• WATER LEVELS FOR BARBADOS (1994)
• JAN 99 S/DIST DEVELOPMENT PROJECT
• S/D SOIL CONSERVATION/ DEV STUDY 99
• DRAFT NATIONAL PHYSICAL DEV. PLAN (FEB 98)

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DRAINAGE STUDY

• Collect and analyse Data (rainfall, runoff,
  flooding and land use for the period 1973- 93
• Locate and study all flood prone sites within the
  study area and recommend practical solutions and
  effective flood control measures
• Develop a Works Programme comprising the least
  cost design
• Carry out an evaluation and assessment of the
  institutional requirements for O M of present
  and future drainage works in Bdos

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SOME ELEMENTS EXAMINED

• Confirmation of Drainage boundaries using
  (topographic mapping, field reconnaissance, and
  air photos)
• Determination of drainage characteristics (area,
  length, topographic rise, slope, of impervious
  area, runoff coefficient).
• Peak Flows at Culvert and Bridge locations were
  estimated and compared to expected flows to
  assess the flood potential. 2, 5, 10, 20, 25,
  50, 100 year events were estimated

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HISTORICAL FLOOD AREAS

• PRESCOT LAND/CONSTITUTION RIVER - St Michael
• GRAME HALL - Christ Church
• SPEIGHTSTOWN - St Peter
• AQUATIC GAP - Christ Church
• HOLETOWN - St James
• BAYLAND - St Michael
• WOTTON - Christ Church
• GIBBES - St Peter

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FLOOD PLAIN AREAS

• SPEIGHTSTOWN From outlet to up stream of Round
  The Town bridge
• HOLETOWN From outlet to easterly limits of
  Jamestown Park
• CONSTITUTION RIVER From Duncan ONeal bridge to
  Bridge Road
• WESTON From outlet upstream for 190 m

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CHARACTERISATION OF FLOOD AREAS

• MAJOR FLOOD HAZARD AREAS Generally located where
  significant economic losses could occur. Has
  large watershed areas, poses risks to life
  because of higher peak flows, higher runoff
  velocities and higher potential depth of flooding.

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CHARACTERISATION OF FLOOD AREAS

• NUISANCE FLOOD HAZARD AREAS Associated with
  smaller watersheds, shallower depths of flooding
  and reduced potential for injuries, loss of life
  and economic losses

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WORKS PROGRAMME

• STRUCTURAL MEASURES CONSIDERED
• Construction of drainage channels
• Use of reservoirs and quarries to control flood
  peaks
• Construction of dykes and or upgrading of
  bridges, culverts, and other drainage
  infrastructure

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WORKS PROGRAMME

• NON STRUCTURAL MEASURES
• Revisions to legislation for mitigation of flood
  losses
• Control of development in flood prone areas
• Encourage alternative landuse and agricultural
  practices which promote flood mitigation

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WATER LEVELS FOR BARBADOS (1994)

• RELATIVE SEA LEVEL RISE
• TIDAL WATER LEVEL CHANGES
• METEOROLOGICAL WATER LEVEL CHANGES
• WAVE INDUCED WATER LEVEL CHANGES
• TSUNAMI
• DESIGN CRITERIA

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TERMS OF REFERENCE

• Determine engineering methods of protecting,
  increasing and or stabalising the size of beaches
  along the west and south coasts
• Prepare land use planning recommendations for the
  south and west coastal zones, on a stretch by
  stretch basis, based on the need to preserve and
  enhance the coastal resource within a national
  economic context

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OBJECTIVES

• Determination of the normal and extreme levels of
  the astronomic tidal component
• Analysis of any surge events that were present in
  the existing recorded tidal data
• Examination of the wind and barometric components
  of hurricane related surge at several locations

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OBJECTIVES (contd)

• Analysis of the wave-induced set-up and run-up,
  giving consideration to different shoreline,
  beach and structure characteristics at or near
  the shoreline
• Quantification of the most up to date information
  on long-term sea level change

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SCOTLAND DISTRICT STUDIES

• Geological Investigations of Ground Water
  Resources 46
• S/D Development Study 79
• GeologyMineral Resource Assessment 82
• S/D Soil Conservation Project 83 -87
• Water Resources Management Water Loss Study 96
• Field Guide to the Sub-Quanternary of Bdos 97

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POLICIES PROGRAMMES

• Prioritising of occupied spots for relocation of
  houses (Priority 1, 2, 3)
• Down grading of specific roads in Priority 1
  areas to maintain for agricultural purposes only
• Consolidation and stabalisation of highways
• Identification and redirection of streams
• Reforestation of areas which held relocated houses