Unit 4 - Water and its Management

Key terms in the textbook & revision guide

Sanitation

Sanitation

The conditions necessary for health (such as providing clean drinking water and the safe disposal of sewage)

Precipitation

The process in which liquid water (rain) or ice particles (snow or hail) fall to Earth due to gravity

Surface run-off

Precipitation that flows over the ground surface, eventually finding its way into streams and rivers

Interception

Precipitation that doesn’t reach the Earth’s surface due to the obstruction by trees and plants

Infiltration

Precipitation which soaks into sub-surface soils and moves into rocks through cracks and pores (water seeps into the ground)

Through-flow

The process by which infiltrated water flows through the soil

Groundwater Flow

The process by which infiltrated water flows through rocks

Evaporation

Water from oceans, seas and other water sources which change from water droplets to water vapour in the atmosphere due to heat

Transpiration

The movement of water up plants and its subsequent loss as water vapour from their leaves

Condensation

Water vapour converted back into liquid or solid due to a decrease in temperature (with increasing height by air currents)

Surface Water

Water in lakes, rivers and swamps

Ground Water

Water in the soil, and in rocks under the surface of the ground

Aquifers

Water stored in porous rocks under the ground

Artesian Aquifers

Aquifers in which the water is under pressure

Potable

Safe to drink

Reservoirs

Artificial lakes used as a source of water supply, usually created behind a dam or by the side of a river (bank-side reservoir)

Service Reservoirs

Reservoirs where potable water is stored (i.e. water towers & cisterns)

Wells

A hole bored or dug into rock to reach the water stored in them

Desalination

The removal of salt from seawater

Distillation

Water which is boiled and released as vapour, leaving salt behind

Reverse Osmosis

Pumping water at a high pressure through a fine membrane

Water-rich countries

Countries with plentiful freshwater supplies

Water-poor countries

Countries with scarce freshwater supplies

Water Conflict

Conflict between countries, states or groups over an access to water resources

Physical water scarcity

Not enough water to meet both human demands and those of ecosystems to function effectively

Economic water scarcity

A situation in which there is enough water available but the money does not exist to extract and or treat enough of it for human needs

Sewage

Waste matter that is carried away in sewers or drains from domestic (or industrial) establishments

Biomagnification

Increases concentration of a toxic substance in the tissues of organisms at successively higher levels in a food chain, causing illness

Bioaccumulation

The accumulation of a toxic substance in the tissue of a particular organism

Flush toilet

Uses a holding tank for flushing water, and a water seal that prevents smells

Pour toilet

Toilets which have a water seal but uses water poured by hand for flushing

Pit latrine

Type of toilet that collects human faeces in a hole in the ground that is sometimes ventilated to take away smells

Composing toilet

A dry toilet in which vegetable waste, straw, grass, sawdust and ash are added to the human waste to produce compost

Water treatment

Water is made potable by undergoing coagulation treatment, being filtered and/or disinfected

Chlorination

Chlorine used as a disinfectant to kill remaining pathogens

Water-borne disease

Diseases which are spread by consuming contaminated water due to poor sanitation and untreated sewage, or by washing food, pots. and pans, or hands and face in dirty water

Cholera

Intestinal infection that causes severe diarrhoea that may lead to dehydration and eventually death

Water-bred dieases

Diseases where the carrier breeds in water and spreads the disease by biting its victims

Malaria

A life-threatening disease which is transmitted through the bite of an infected mosquito (vector) that carries the Plasmodium parasite

Pathogen

An organism, including bacteria and viruses, that can cause disease

Vector

An organism that carries a disease-producing organism (such as the mosquito which carries the malarial parasite)

Effluent

A discharge of liquid waste

Dieback

The death of a tree or shrub that starts at the tip of leaves or roots and spreads towards the centre of the plant, caused by unfavourable environmental conditions or disease

Leaching

The movement of a soluble chemical or mineral away from soil, usually caused by the action of rainwater

Algae

Plant-like, photosynthetic organisms that lack true stems, roots and leaves

Algal bloom

The rapid growth of algae in water, caused particularly by a surge of nutrients

Eutrophication

A sequence events starting with enrichment of water by mineral nutrients or organic mater that leads to reduction in oxygen levels in the water and the death of fish and other animals