Edexcel A Level Geography - Water Cycle Terms Only.

what is the hydrological cycle known as

a system comprised of

stores - the holding of water

flows - measure the rate of flow between stores

processes - physical factors that drive the water

what drives the hydrological cycle

Solar energy and gravitational potential energy

what is the global water budget

the annual balance of water flows and the size of the water stores

what is residence time

the average time a water molecule will spend in a reservoir or store

how much percent of the earths water is stored in the ocean

97%

what is a drainage basin

an area of land drained by a river and its tributaries

what is a watershed boundary

an area of land that separates water flowing to different rivers

what is the ITCZ

inter tropical convergence zone, it is a low pressure belt encircling the Earth, near the equator, it moves and impacts precipitation

the 3 cells around the earth giving different temperatures at different latitudes

polar - 60-90 degree

ferrel - 30-60 degree

hadley - 0-30 degree

what is convectional rainfall

Due to heating by the sun, warm air rises, condenses at higher altitudes and falls as rain

what is orographic rainfall

caused by uplifting and cooling of moist air over mountains

what is frontal rainfall

when a warm air mass meets a cold air mass, forcing the warmer air to rise and cool over the denser air

The UK's rainfall

the tees- exe line separates the rainfall of the UK, with orographic rainfall mainly happens in the west, and convectional in the south, but over a year, frontal rainfall brings the most to the whole UK

how does deforestation affect the drainage basin

reduces evapotranspiration, less ground water to aid in dry days, rainwater runs quickly, flooding

3 human factors affecting a drainage basin

deforestation, urbanisation reservoirs

how does urbanisation affect a drainage basin

buildings have far more run off than nature at 55% to 10%, and far less infiltration and deep infiltration

how does reservoirs affect a drainage basin

they are man made, that interrupt the flow of water, reduce river flow, e.g Kenya tana river flood plain forest is dying lack of floods upstream

what physical factors affect a drainage basin

vegetation cover

temperature

geology

soil type

what is the only input to a drainage basin

precipitation

what is the water budget

show the annual balance between inputs and outputs

What does the water budget graph show

what is precipitation

rain, snow, sleet, or hail that falls to the ground.

what is interception

A temporary storage whereby water is captured by plants and buildings before reaching the ground.

what is surface storage

water in lakes, ponds, puddles

what is ground water storage

water held within permeable rocks

what is percolation

When water moves vertically down through soil and rock

what is evapotranspiration

the combined effect of evaporation and transpiration

what is river discharge

The volume of water passing a measuring point in a given time.

what is a river regime

the difference in the discharge of the river throughout the year

what is a simple regime

One where a river has a period of seasonally high discharge (glacier melt, monsoons), followed by low discharge.

what is a complex regime

One that is affected by many variables because they are larger and cross several relief and climatic zones. they are affected by human factors

what is a flashy river

a river with a short lag time, fast flow, impermeable surface

what is a flat river

a river with a long lag time

what is a storm hydrograph

a graph that shows changes in discharge of a river over a short period of time

4 types of drought

meteorological - precipitation is below average

agricultural - lack of growth due to no rain

hydrological - lack of water supplies in streams

socioeconomic - the impact on the population

what is a anti cyclone

areas that experience intense high pressure and sinking air, pressure of 1008mb

What does ENSO stand for

El Nino Southern Oscillation

What is the ENSO cycle, where does it happen between

Movement of warm water mass in the equatorial Pacific Ocean

Australia to south America

what is the 'normal condition' in the pacific ocean

Warm water by Australia and east Aisa, causing warm air to rise, lots of rain

Cold water by South America, air sinks, high pressure and no rain

What is La Nina

the process of intensifying normal conditions

What is El Nino

Weather patterns swap, heavy rainfall in S America, Droughts in Australia

What does over abstraction mean

the amount of water used has been too much and not enough has been replenished, leads to water scarcity.

what is a aquifer

body of permeable rock that can hold or transmit ground water.

what is a confined aquifer

covered by permeable rock deep down, hard for water to get to

what is a unconfined aquifer

a groundwater layer with no impermeable barrier above it.

impact of over abstraction

water reduce in layers

water quality falls

water table sinks

how can humans increase drought risk

deforestation

over-abstraction

impact of deforestation on drought risk

deforestation = no evaporation = less rainfall = decrease in discharge

what does ecosystem functioning mean

the biological, physical and chemical processes that take place within an ecosystem.

impact of drought on forest

younger trees die, canopy cover reduces, exposing dry surface litter fire prone.

what does surface water flooding mean

flooding that occurs when intense rainfall has not enough time to infiltrate the soil , flows overland

what does groundwater flooding mean

prolonged heavy rain, cause land to become saturated, as a result floods happen

what does flash flooding mean

high level of rain, short lag time flood

physical causes of flooding

amount and type of rainfall - influence intensity of rain

impermeable material

relief ( land angle )

human causes of flooding

urbanisation

deforestation

land use

infastructure

what does water scarcity mean

lack of water supply

what is water stress

demand for water exceeds supply

how much percent of the worlds population consume how much of the worlds water.

12% of population = 85% of water

what is privatisation

the transfer of a business, industry, or service from public to private control.

impact of water privatisation

more expensive. e.g Bolivia - 2000, water in rural area cost 20% of average income.

causes of water insecurity

increasing population and urbanisation - Africa and Asia urban population by 2030 2x.

industrialisation - OECD report - global water demand for manufacturing will increase by 400% between 2000-2050

agriculture - some developing countries, 90% of water used on farming

what are the 3 hard engineering strategies used to control water supplies.

- mega dams

- transfer projects

- desalination plants

3 soft engineering strategies to manage water

rain water harvesting

smart irrigation

recycling gray ( agriculture use only ) water

what is integrated water resoucre management (IWRM)

managing water in a fair access