|Environment and development
in coastal regions and in small islands
ANALYSIS OF BEACH
CHANGES IN ANTIGUA AND BARBUDA 1996 – 2001
Volume 1 Assessment Report June 2003
ACRONYMS CDB Caribbean Development Bank COSALC The Project: Coast and Beach Stability in the Caribbean CPACC Caribbean Planning for Adaptation to Climate Change CRIS Coastal Resources Information Systems CSI Environment and Development in Coastal Regions and Small Islands, (UNESCO) DCA The Development Control Authority FD Fisheries Division GIS Geographical Information Systems GPS Geographical Positioning System MCW Ministry of Communications and Works (Public Works) MTE Ministry of Tourism and the Environment NGO Non-Government Organisation OAS Organization of American States OECS Organization of Eastern Caribbean States UNESCO United Nations Educational, Scientific and Cultural Organization UPR-SGCP University of Puerto Rico Sea Grant College Program USAID United States Agency for International Development
DEFINITION OF IMPORTANT TERMS Accretion: Accumulation of sand or other beach material due to the natural action of waves, currents and wind; a build-up of sand or other beach material. Back beach: The section of beach extending landwards from the high water mark to the point where there is an abrupt change in slope or material; also referred to as the backshore. Beach: The area or zone where the sea interfaces with the coastline. This usually consists of deposits (sand, pebbles, etc.). Beach nourishment: Artificial process of replenishing a beach with material from another source that is located either inland or is dredged offshore. Beach profile: Side view of a beach extending from the top of the dune line into the sea. Beach recovery: Process whereby accretion takes place at a beach, usually after a major storm or hurricane. Beachrock: Ledges of rock formed within the body of the beach consisting of sand grains cemented by calcium carbonate and formed by chemical processes. Erosion of the sand leaves the beachrock exposed. Beach Segment: Any part of a stretch of beach. Berm crest: Ridge of sand or gravel deposited by wave action on the shore just above the normal high water mark. Dredging: Excavation, digging, scraping, drag-lining, suction dredging to remove sand, silt, rock or other underwater sea-bottom material. Dune: Accumulations of wind-blown sand in ridges or mounds that lies landward of the beach and usually parallel to the shoreline. Dunes shift periodically. Ecosystem: Organization of the biological community and the physical environment in a specific geographical area. Erosion: Wearing away of the land, usually by the action of natural forces. Foreshore: Zone between the high water and low water marks. Groyne: Shore protection structure built perpendicular to the shore; designed to trap sediment. Also, groin. High water mark: The highest reach of the water at high tide. It is sometimes marked by a line of debris, e.g. sea grass, pieces of wood, etc, Hurricane: Intense, low-pressure, tropical weather system with maximum surface wind speeds that exceed 118 km/hr (74 mph). Leeward: The lee or sheltered side. Leeward coast: Coast sheltered from the waves. Longshore current: A movement of water parallel to the shore, caused mainly by waves. Longshore drift: Movement of material parallel to the shore also referred to as longshore transport. This results from the action of longshore currents. Low water mark: The highest reach of the water at low tide. Monitoring: Systematic measurement and recording over time. Profile Area: Cross-sectional area under the beach profile. Profile Width: Horizontal distance across the beach profile, measured from the base of the fixed reference point to the first offshore step. Revetment: Shore protection structure made with stones laid on a sloping face. Sea grass bed:
Area of the sea-bottom colonized by sea grasses.
Seasonal deposition: Accumulation of sand or other beach material, usually layered, resulting from seasonal variations in coastal processes. Seasonal erosion: Loss of sand or other beach material resulting from seasonal variations in coastal processes. Setback: Prescribed distance landward of a coastal feature from a standard feature (e.g. the line of permanent vegetation), within which all or certain types of development are prohibited. Shore: Narrow strip of land in immediate contact with the sea. Shoreline: Intersection of a specific water height with the shore or beach, e.g. the high water shoreline is the intersection of the high water mark with the shore or beach. Swell: Waves that have traveled out of the area in which they were generated. Topography: Configuration of a surface including its relief and the position of its natural and man-made features. Tropical depression: Organized low-pressure system forming in tropical latitudes with wind speeds of between 37 km/h and 60 km/h (23 mph and 37 mph). Tropical storm: Low-pressure weather system with maximum surface wind speeds between 61 km/h and 118 km/hr (38 mph and 74 mph). Tropical wave: Low-pressure system forming in tropical latitudes with wind speeds of up to 36 km/h (22 mph). Tropical Weather System:
In reference to the Caribbean Region, any one of or a combination of the following: Tropical wave, Tropical depression, Tropical storm, hurricane.
Wave breakpoint: The point where the waves break. Wetlands: Low-lying areas that are frequently flooded and which support vegetation adapted to saturated soils e.g. mangrove swamps. Windward: Side facing the prevailing wind. Windward coast: Coast exposed to wave action as a result of facing the prevailing wind.
Executive Summary, Introduction, Background