BackscatterBackscatter is the portion of the outgoing radar signal that the target redirects directly back towards the radar antenna.
BacteriaMicroscopic, single-celled prokaryotic organisms.
Bankfull dischargeThe level of flow occurring when water overflows the channel banks and begins to spread onto the floodplain.
BantuThe term Bantu is broadly associated with the cultural and language group originating in west Africa in about 3 000 BC, the descendants of whom migrated east and south throughout sub-Saharan Africa. However, it was also used by the former Apartheid government of South Africa from the 1920s onwards as a term to collectively describe African members of the population. Thus, it has become associated with this period and is generally seen as racially offensive and is generally not accepted in modern society.
BarrageAn artificial obstruction at the mouth of a tidal watercourse.
BasaltA dark colored fine grained igneous rock formed from mafic magma.
BasarwaRefer to hunter-gatherer peoples of southern Africa.
BaseflowPart of the discharge which enters a stream channel mainly from groundwater, but also from lakes and glaciers during long periods when no precipitation or snowmelt occurs.
BaselineConditions prior to change.
BasinA river basin includes the river channel and surrounding drainage area – that is, the land and tributaries that drain precipitation falling within this area to the river.
Basin statesStates that are part of a special river system.
BasothoThe Basotho people have lived in southern Africa since around the fifteenth century. The Basotho nation (modern Lesotho) emerged from the accomplished diplomacy of Moshoeshoe I who gathered together disparate clans of Sotho-Tswana origin that had dispersed across southern Africa in the early 19th century. Most Basotho today live in South Africa.
BedrockRock at or near (beneath soil and regolith) the Earth's surface that is solid and relatively unweathered.
Benefit sharingAn exchange between those who grant access to a particular resource and those who provide compensation or rewards for its use.
BenefitsSomething that aids or promotes well-being. Direct & indirect benefits are gained from ecosystem goods and services.
BenthicOrganisms living in or on aquatic sediments (river or lake bottoms).
BethulieBethulie is a small sheep and cattle farming town in the Free State province of South Africa. The town was also home to one of the largest concentration camps run by the British during the Boer War.
BilharziaA tropical disease spread by parasitic worms living in fresh water, hosted by snails, that can cause rash or itchy skin, fever, chills, muscle aches, and possible damage to the liver, intestines, lungs, and bladder. Also known as schistosomiasis.
BioaccumulationIncrease in concentration of toxic fat-soluble chemicals in organisms at successively higher trophic levels of a grazing food chain or food web because of the consumption of organisms at lower trophic levels.
BioavailabilityAble to be absorbed by a living organism.
BiodiversityRefers to the variety of life on earth. The most widely accepted definition of biodiversity is found in Article 2 of the Convention on Biological Diversity: “Biological diversity means the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems.”
BiofilmA thin layer of biota—including algae, fungi, bacteria, and other invertebrates—that forms on river and lake substrate.
BiomagnificationA process in which concentrations of certain compounds found in tissues of organisms increase in successive levels of the food chain.
BiomassThe mass of all living and dead organic matter in an ecosystem. In certain contexts, the term ‘biomass’ may also refer only to the mass of living organisms in an environment.
BiomeLargest recognizable assemblage of animals and plants on the Earth. The distribution of the biomes is controlled mainly by climate.
BiophysicalThe biological and physical components of the environment .
BiotaAll plant and animal life in a particular region or area.
BivalveShellfish with two parts to their shell.
Blue waterThe water in rivers, lakes and shallow aquifers. (In the past this has received most of the attention from planners, engineers and policymakers because of its association with established forms of irrigation.)
Bm3Billion cubic metres.
BoerBoer is the Dutch word for farmer which came to denote the descendants of the proto Afrikaans-speaking pastoralists of the eastern Cape frontier in Southern Africa during the 18th century as well as those who left the Cape Colony during the 19th century to settle in the Orange Free State, Transvaal (together known as the Boer Republics) and to a lesser extent Natal. Their primary motivation for leaving the Cape was to escape British rule as well as the constant border wars between the British imperial government and the native tribes on the eastern frontier.
BoreholeGroundwater well drilled or dug into the ground for exploration for water or abstraction of water.
Brak RiverThe river in the Western Cape Province of South Africa.
BreadbasketA geographic region serving as a principle source of grain supply.
Bulk Transfer (of water)The removal and transfer of water out of its basin of origin by man-made diversions, tanker ships or trucks, and pipelines.
BuoyantFloats on water.
BushmenOne of the major tribal groups of the Orange-Senqu River basin.