Water Flashcards
(47 cards)
What is the global water budget?
the annual balance of water fluxes and the size of water stores
What is one type of non-renewable water source?
Fossil water
What is the drainage basin?
the area of land driven by a river and tributaries
What is the watershed?
the boundary of the drainage basin
What is orographic rainfall?
water vapour is forced up the mountain and it cools and condenses due to altitude. Precipitation then occurs over the mountains
What is cyclonic rainfall?
warm and cool air meet and as warm air is less dense it rises and condenses
What is conventional rainfall?
normally happens in a 24 hour cycle where insolation starts evaporation which leads to precipitations later in the day
Factors which factors which affect basin flows and fluxes?
Infiltration, interception, rainfall, overland flow, percolation and evaporation/transpiration
Physical factors which affect a drainage basin
Climate, soil, geology, relief and vegetation
Human factors which affect a drainage basin
Urbanisation, dams, deforestation and over grazing
Factors which impact river regime
Size of basin, precipitation, geology, temperature and human activities
What is a drought?
an extended period of deficient rainfall relative to the statistical multi-year average for a region
What is a meteorological drought?
occurs when long-term precipitation is much lower than normal
What is an agricultural drought?
occurs when there is insufficient soil moisture to meet the needs of particular crops at a particular time
What is a hydrological drought?
occurs when there are deficiencies in surface and subsurface water supplies, measured in rivers, lakes and groundwater
What is a socio-economic drought?
occurs when the water demand for social and economic purposes exceeds water availability
What are the physical causes of drought?
ITCZ, Mid-Atlantic blocking anticyclones, ENSO and other general processes (intense solar radiation)
What is the ITCZ?
A belt of low atmospheric pressure located around the equator moves north and south of the equator seasonally
wet seasons= when it arrives
dry seasons=when it moves away
What are Mid-Atlantic blocking anticyclones?
Precipitation is created when warm tropical air rises over cold polar air
These anticyclones bring stable conditions with little precipitation (heat waves) and forcing rain-baring depressions out
What is the ENSO?
El Nino is a naturally occurring large mass of very warm seawater in the equatorial Pacific Ocean
Warm moist air is pushed from South America to Australia by ocean currents, creating precipitation
What are human causes of drought?
over abstraction, reservoirs/dams, deforestation, overgrazing, enhanced greenhouse effect and urbanisation
What is an ecosystem?
an interconnected community of living organisms within a defined physical environment
What is a biome?
the specific geographical location where animals and plants interact
What are benefits of wetlands to humans?
research, tourism, aesthetics, education, freshwater source
