Glossary of Terms
Steel wire-mesh basket to hold stones or crushed rock to protect a bank or bottom from erosion. Structures composed of masses of rocks, rubble or masonry held tightly together usually by wire mesh so as to form blocks or walls. Sometimes used (although not recommended) on heavy erosion coastal areas to retard wave action.
Database of information which is geographically referenced, usually with an associated visualization system.
A navigational and positioning system developed by the U.S. Department of Defense, by which the location of a position on or above the Earth can be determined by a special receiver at that point interpreting signals received simultaneously from several of a constellation of special satellites.
Unconsolidated natural accumulation of rounded rock fragments coarser than sand but finer than pebbles (2-4 mm diameter).
Gases that trap heat radiating from the Earth's surface, thereby warming the lower atmosphere.
Water that occupies pores and crevices in rock and soil, below the surface of the Earth. The upper limit of the groundwater is the water table, whose level varies according to the quantity of water entering and extracted from the groundwater. (See also aquifers).
Narrow, roughly shore-normal structure built to reduce longshore currents, and/or to trap and retain littoral material. Most groins are of rock and extend from the backshore, well onto the foreshore and rarely even further offshore.
A series of groynes acting together to protect a section of beach. Also called a groyne system.