A
Abiotic the non-living component of the environment; not pertaining to life or living organisms.
AbrasionWhere rock pieces move against another rock and wear it away, e.g. a
pebble is washed against a cliff by waves and breaks off tiny bits of the
cliff. If you rub two pebbles together you will have abrasion and the pebbles
will begin to be worn away. You can try it with two pieces of chalk. Abrasion
will cause them to crumble to powder.
Acceptable Risk A risk, which, for the purposes of life or work, everyone who might be
impacted is prepared to accept assuming no changes in risk control
mechanisms. Action to further reduce such risk is usually not required
unless reasonably practicable measures are available at low cost in
terms of money, time and effort.
Accretion The addition of new land to the shoreline through the
action of natural forces depositing water- or airborne material or by
reason of an act of man such as the accretion formed as a result of
groin or breakwater construction, or beach fill deposited by mechanical
means; also defined as the process of gradual and imperceptible
Aeolian deposits Wind-deposited sediments, such as sand dunes.
Aerobic living or active only in the presence of oxygen; taking place in the presence of oxygen.
AggradationThe geologic process by which various parts of the surface of the earth are raised in elevation or built up by the deposition of material transported by water or wind.
Algal bloom an overgrowth of algae in water that can shade out other aquatic plants
and use up the water’s oxygen supply as the plants decompose; blooms
are often caused by pollution from excessive nutrient input.
Allochtonous A term applied to shelves that presently experience deposition of river-derived sediments.
Alluvial deposits Detrital material which is transported by a river and deposited - usually temporarily - at points along the floodplain of a river. Commonly composed of sands and gravels.
Alongshore Parallel to and near the shoreline; same as longshore.
Alternative livelihoods jobs offered to people who are displaced from their current jobs because of resource conservation programs.
Angle of repose The maximum slope(measured from the horizon) at which soils and loose
materials on the banks of canals, rivers, or embankments stay
stable.
Anoxic devoid of free oxygen
Anthropogenic effects from the influence of human beings on natural systems.
Apron Layers of stone, concrete or other material to protect the toe of a structure such as a seawall.
Aquaculture the cultivation of fish, shellfish, and/or other
aquatic animals or plants, including the processing of these products
for human use.
Aquifer A geologic stratum that contains water than can be economically removed and used for water supply.
ArchWhere the sea has worn a hole right through a
cliff so the cliff looks like a bridge.
Armor A marine engineering term that means providing structural protection for shorelines; e.g., bulkheads, seawalls etc.
Armor levee The armor levee is a levee covered with an armor so that it is not
Artificial reef Any marine habitat constructed for the purpose of attracting marine
species or enhancing marine resources to improve fisheries; usually
made of terrigenous substances such as used auto tires, concrete
rubble, old ship hulls, automobile bodies, etc.
Aseismic ridge A submarine ridge with which no earthquakes are associated
Asset Status This refers to an individual’s or group’s access to
livelihood assets. A change in Asset Status may involve an increase or
decrease in access to livelihood assets or a change in the composition
of the livelihood assets to which there is access.
at or near the crest of the beach, to resist erosion, usually timber.
Attrition The reduction and rounding of
particles of sediment carried in water by repeated collision with each other
and the shore.
Avulsion (1) Rapid erosion of the shoreland by
waves during a storm.
(2) A sudden cutting off of land by flood,
currents, or change in course of a body of water