Key terms - physical systems and sustainability Flashcards
what is afforestation?
The planting of trees on land that has never had forest, or has been without forest for a long time.
what is agricultural drought?
A rainfall deficiency from meteorological drought that leads to deficiency of soil moisture and soil water availability, which has a knock on effect on plant creating vegitation stress and reduces biomass production.(intermediate dryness)
what is a aquifer?
A permeable or porous rock which stores water underground.
what is base flow?
The normal, day-to-day discharge of the river.
what is blue water?
Water stored in rivers, streams, lakes and groundwater in liquid form (the visible part of the hydrological cycle).
what is a catchment?
The area of land drained by a river and its tributaries.
what is a closed system?
A sequence of linked processes with a transfer of energy but not matter between the parts of the system (the inputs and outputs happen within the system). An example is the global hydrological cycle
what is condensation?
The change from a gas to a liquid, such as when water vapour changes into water droplets.
what is convectional rainfall?
occurs during the summer in the UK, when the sun heats the land, This creates rising pockets of warm air, known as convection currents it rises rapidly, where it starts to cool and condenses to form clouds. The clouds can produce heavy rainfall and thunderstorms.
what is the cryosphere?
Areas of the Earth where water is frozen into snow or ice.
what is Cyclonic rainfall?
A period or sustained, moderately intensive rainfall; it is associated with the passage of depressions.
what is deforestation?
The cutting down and removal of all or most trees in a forested area.
Desalination?
The process of converting saltwater to freshwater suitable for human consumption and industry.
Desertification?
Land degradation in arid, semi-arid and dry sub-humid regions resulting from various factors, including climatic variations and human activities.
Dew point?
The temperature at which dew forms; it is a measure of atmospheric moisture.
Drought?
The definition varies internationally. According to the UN, drought is an extended period (a season, a year or several years) of deficient rainfall relative to the statistical average for a region measured over a very long period of time.
Economic water scarcity?
Occurs when water resources are available but there is insufficient human, institutional and financial capital to access the water in order to meet demand.
ENSO cycle?
mass of very warm water in the equatorial Pacific due to changes in There are two phases- El Niño (warm water to the east) and La Niña (warm water to the extreme west).
A naturally occurring phenomenon that involves the movement of a the surface trade winds, atmospheric circulation and ocean currents.
Eutrophication?
Excessive richness of nutrients in a lake or other body of water, frequently due to run-off from farming land, which causes a dense growth of plant life and death of animal life from a lack of oxygen.
Evaporation
The change in state of water from a liquid to a gas.
Evapotranspiration
The combined effect of evaporation and transpiration.
Falling or recessional limb
The part of a storm hydrograph in which the discharge starts to decrease and return to base flow.
Famine drought
A humanitarian crisis in which the widespread failure of agricultural systems leads to food shortages and famines with severe social, economic and environmental impacts.
Flash flooding
A flood with an exceptionally short lag time- often minutes or hours.
Fossil water
Ancient, deep groundwater from former pluvial (wetter) periods.
Frontal rainfall
Occurs frequently in mid-latitudes when a warm tropical air mass meets a cooler polar air mass. The warmer air is less dense and rises over the colder air, which causes the warm air to cool, leading to condensation of water vapour, The clouds bring heavy rain.
Green water
Water stored in the soil and vegetation (the invisible part of the hydrological cycle).