Area of Outstanding Natural Beauty (AONB) - in the UK, land areas given special protection by
act of parliament to preserve their natural beauty. Local authorities maintain strict control over
permission for development within them. England has 35, Wales
Aeolian- lit. 'of the wind' Refers to transportation, erosion and deposition by wind action.
Afforestation - planting of trees on previously un-wooded land.
Aftershock - ground tremors occurring after a major earthquake but associated with the same
Algae - collective name for a group of chlorophyll-containing plants, ranging in size from single
cells to stems, including seaweeds and freshwater forms.
Algal bloom - rapid growth of phytoplankton in water bodies usually in the surface layers. May
Aspect -direction in which a slope faces.
Asthenosphere - layer of rock in the mantle approximately 80km deep and at a temperature of
1400C. Rocks here become much softer and more easily deformed than in the lithosphere
Athalassohaline - water with
Abiotic lit. not from living things. In physical geography, used to describe non-living
components of an environment such as rock or water.
Ablation the net loss of water from a glacier through melting, calving, evaporation, sublimation
or wind transport.
Alternative technology -(usually interchangeable with appropriate or intermediate technology)
the use of low-cost, often labour-intensive, technology, based on local resources, that is
appropriate to Economically Less Developed Countries. May originate in
Accessibility - the level of difficulty associated with getting to a location or feature within a
larger area measured in distance, time and/or cost.
Accretion - growth of a natural feature by enlargement due to the addition of more of the same
Agricultural chain - every step in the process(es) that lead to the consumption of food.
Agricultural revolution - a period of fundamental changes to agricultural systems which tend to
concentrate land and production into fewer hands while increasing yiel
Appropriate technology - see alternative technology. Appropriate technology might more
commonly be the term applied to alternative technology originating externally.
Aquaculture- highly managed use of water environments to enhance food production e.g. fis
Acid rain - refers to the unnatural increase, through human pollution, in the acidity of water
precipitation. Most commonly sulphuric and nitric acids formed from by-products of fossil-fuel
burning and metal smelting.
Acquired immune deficiency syndrome -