Term |
Description |
Backshore |
The upper part of the active beach above the normal reach of the tides (high water), but affected by occasional large waves occurring during a high tide/storm surge. |
BAP |
Biodiversity Action Plan |
Barrier beach |
A sand or shingle bar above high tide, parallel to the coastline and separated from it by a lagoon. |
Bathymetry |
Refers to the levels of the seabed and their variability. |
Beach |
A deposit of unconsolidated material (e.g. sand, gravel) situated on the interface between land and the sea (or other large expanse of water) and actively "worked" by present-day hydrodynamic processes (i.e. waves, tides and currents) and occasionally by winds. |
Beach crest |
The point representing the limit of high-tide storm wave run-up. |
Beach face |
From the beach crest to the limit of sediment movement offshore. |
Beach nourishment |
Active replenishment of beach material |
Beach profile |
A cross-section taken perpendicular to a given beach contour. The profile may include the face of a dune or seawall, extend over the backshore, across the foreshore and seaward into the nearshore zone. |
Beach recharge |
Augmenting the natural volume of sediment on a beach, using material from elsewhere - also known as beach replenishment/nourishment/feeding. |
Bed shear stress |
A measure of energy transfer to the seabed from water movements. |
Bedforms |
Features on a seabed or shore (e.g. ripples and sand waves) resulting from the movement of sediment over it. |
Bedload |
Sediment transport mode in which individual particles either roll or slide along the seabed as a shallow, mobile layer a few particle diameters deep. |
Bench mark (BM) |
A fixed physical object or mark used as reference for a vertical datum. |
Beneficial use |
Dredged material used and not disposed of at sea, for example in reclamation, beach recharge, beach nourishment and other uses. |
Benthic |
Of the organisms that live in or on the seafloor |
Benthos |
Organisms living on or in the seafloor |
Berm |
A nearly horizontal plateau on the beach face or backshore. |
Bioaccumulation |
A process by which chemical substances are accumulated by aquatic organisms from water directly or through consumption of food containing the chemicals. |
Biogenic |
Produced by organisms. |
Bore |
A broken swell wave travelling shorewards across the surf zone. |
Boulder |
A rounded rock on a beach, greater than 250 mm in diameter, larger than a cobble (see also gravel, shingle). |
Boundary conditions |
Environmental conditions (e.g. waves, currents, sediment transport, etc) used as boundary input to physical or numerical models. |
BP |
Before present (usually refering to years before present time) |
BP |
Before present |
Breaching |
Failure of the beach barrier allowing flooding by sea to area behind. |
Breaker Index |
The ratio between the height of a wave and the water depth in which the wave breaks. |
Breaker Zone |
That area of coastal waters where shoaling effects cause swell waves to break. |
Breaking Waves |
As waves increase in height through the shoaling process, the crest of the wave tends to speed up relative to the rest of the wave. Waves break when the speed of the crest exceeds the speed of the advance of the wave as a whole. Waves can break in three modes: spilling, surging and plunging. |