TOPIC 6 WATER - A LEVEL GEOGRAPHY - EDEXCEL

Anticyclone

A system of high pressure, causing high temperatures and unseasonably high evaporation rates.

Aquifer

A permeable or porous rock which stores water

Channel Flow

Water flowing in a rivulet, stream or river

Convectional Precipitation

Solar radiation heats the air above the ground, causing it to rise, cool & condense forming precipitation (often as thunderstorms)

Cryosphere

The global water volume locked up within a frozen state (i.e. snow and ice)

Depression

A system of low pressure, with fronts of precipitation where low and high pressure air masses meet.

Desalination Plant

The conversion of seawater to freshwater, suitable for human consumption.

Desublimation

The change of state of water from gas to solid, without being a liquid (the opposite process to sublimation

Drainage Basin

A river basin in an area of land drained by a river and its tributaries. - Complex open system.

Drainage Density

The total length of all rivers & streams divided by the area of the drainage basin

Drought

An extended period of deficient rainfall relative to the statistical average for the region (UN)

ENSO Cycles

El Nino Southern Oscillations - naturally occurring phenomena that involves the movement of warm water in the Equatorial Pacific.

Evapotranspiration

The combined effects of evaporation and transpiration. The sum of all processes.

Frontal Precipitation

Where air masses of different temperatures meet at a front, one mass will be forced over another, causing precipitation beneath the front.

Global Hydrological Cycle

The continuous transfer of water between land, atmosphere and oceans. The Earth is a closed system.

Groundwater Flow

Water moving horizontally through permeable or porous rock due to Gravity.

Hydrological Drought

Insufficient soil moisture to meet the needs of vegetation at a particular time

Infiltration

The movement of water vertically through the pores in soil.

Integrated Drainage Basin Management

Establishing a frame of coordinated efforts between administrations (e.g. local government) and stakeholders (e.g businesses) to achieve balanced management of a basin (World Bank)

Interception

Plant leaves / slate roofs intercept rain fall and prevent it from infiltrating into the ground - slows the water transfer rate from the atmosphere into the lithosphere = reducing the likelihood of flooding.

Meteorological Drought

When long-term precipitation trends are below average

Monsoon

The drastic variation between wet and dry seasons for sub-tropical areas, caused by a changed prevailing wind. Can lead to annual flooding.

Open System

A system affected by external flows and inputs (such as a drainage basin, or a sediment cell)

Relief Precipitation

Precipitation caused when air masses are forced to rise over high land, determined by the relief/ morphology of the land

River Regime

The pattern of river discharge over a year

Runoff

Water flowing over the surface of the ground eg. after precipitation or snowmelt.

Salinisation

Where salt water contaminates freshwater stores or soils, creating saline conditions and reducing human use/ consumption.

Saltwater Encroachment

The movement of saltwater into freshwater aquifers or soils. This may be caused by sea level rise, storm surges or over-extraction

Smart Irrigation

Providing crops with a water supply less than optimal, to make crops resistant to water shortages.

Storm Hydrograph

Variation of river discharge over a short period of time (days)

Sublimation

The process of ice turning directly to steam = occurs on glaciers / mountain summits as the sun rapidly heats the ice.

Throughflow

Water moving horizontally through the soil, due to gravity

Transpiration

The water returned to the atmosphere from the biosphere = tiny pores in the plant leaves (stomata) return excess water as vapour to the atmosphere.

Water Budget

The annual balance between inputs and outputs within a system

Water Conservation

Strategies to reduce water usage and demand

Water Recycling

The treatment and purification of waste water, to increase supply

Water Scarcity

There are limited renewable water sources (between 500 and 1000 cubic metres per capita per year)

Water Security

The ability to protect and access a sustainable source to adequately meet demand

Water Sharing Treaty

International agreements for transboundary sources

Water Transfer

Hard engineering projects, such as pipelines or aqueducts, that divert water between basins to meet demand

Watershed

The boundary between neighbouring drainage basins

gravitational potential energy

The mass of the Earth exerts a pull on water, causing water to fall as precipitation and rivers to flow downhill back to the ocean.

solar energy

Heat energy from the sun causes changes in the state of the water and drives some of the processes within the hydrological cycle, such a evaporation and wind widen direction.

water budget equation

Precipitation (Input) = Channel discharge + evapotranspiration (Output) +/- changes in storage

Tropical climate

A type of climate found in the areas just north or south of the equator, where weather is usually hot.

temperate climate

a mild climate between tropical and subarctic climates.

Polar climates

have extremely cold winters and summers. (2) climate types: tundra and ice cap. polar climates are considered the climate of the high latitudes pg. 126

Water demand

The amount needed by people for consumption or activities such as farming and industry.

salt water encroachment

Saltwater replaces freshwater and contaminates wells near coastlines

Over abstraction

When water is being used more quickly than it is being replaced

Intergrated Water Resource Management (IWRM)

It is a planning tool for efficient, equitable and sustainable development and management of the world's limited water source.

Water Management

Can be used to reduce water insecurity, e.g, dams, reservoirs. water transfers, and desalination

Water conflict

Water having a geopolitical role = competition for limited resources is being used as a weapon in stressed political situations.

Quality of life

Means the general well-being of people and includes health, employment, education, human rights, the environment, and wealth. - It's subjective as people have different views of what is important.

Standard of living

It is closely related to wealth, the higher a person's or country's income the greater the standards of living = the greater of other choices / access to goods and services.

Desertification

The degradation of land, particularly arid and semi arid regions.

Trans-boundary River

When countries share the same river or drainage basin

Water footprints

Green, blue and grey

Water Poverty Index

Mathematical data driven tool for gauging the degree of water-related poverty in a community region of country.

WPI Pentagram

There are 5 factors to consider: Resource, Access, Capacity, Use and Environment - Each scored out of 20.

Water Gap

A water gap arises when human demand exceeds the renewable supply -> from rivers, lakes and shallow aquifers refreshed by precipitation.

Zooplankton

Is the animal form of plankton that can be found at a arrange of depths and feeds of phytoplankton.

Phytoplankton

the plant form of plankton using sunlight at the surface waters to photosynthesise.

Physical water scarcity

Is when there is too little water in the area to meet the demand. It is recognised when 75% of a country's water stores and flow are being used.

Economic water scarcity

Is when there is water in an area but it's too expensive for people to access it. It is recognised where the use of water stores and flows is limited by lack of finance, technology or poor governance.

Water scarcity

Occurs when there is less than 1000 m3 of water per day.

Water stress

occurs when there is less than 1700 m3 of water per day.

Water insecurity

the reliable availability of both quantity and quality of water for health, livelihood and production, coupled with an acceptable level of water-related risks.

The carbon pump

is a natural energy force resulting in carbon flux; broth gravity and descending cold currents transfer plankton remains from the ocean surfaces to sea floors..

Thermohaline circulation

Cold water travels at deeper depths and warmer water travels near the surface. It is this continuous flow that mixes the different layers of the oceans, and along with salinity differences creates the ocean currents.

Diffusion

Is the movement of carbon from a region of high concentration to a region of lower concentration. It is a carbon transfer between the hydrosphere and atmosphere and occurs in both directions, known as down-dwelling and up-welling.

Grey water

The volume of polluted water created from the growing and production of goods - this is perused water not sanitation.

Green water

The natural water in soil used by plants to grown. (Biosphere) - the invisible part of the water cycle.

Blue water

Freshwater withdrawn from lakes, rivers and groundwater and used for irrigation, industry and domestic supply - the visible part of the water cycle.

Dynamic Equilibrium

(for the water cycle) = the lack of change in a system as inputs and outputs remain in balance over periods of time.

The sun's role in the water cycle

It heats up water causing for evaporation and evapotranspiration.

Gravity's role in the water cycle

It pulls the water out of the atmosphere back to the ground as precipitation.

Positive feedback

Increases the change, causes for the snow ball effect = enhancing the change further.

Negative feedback

Acts to lessen the effect of the original change and ultimately reverse it.

Albedo effect

Lighter colours reflect heat.

Evaporation

Heat is needed for it to occur. - It can happen at any temperature. - Heat breaks the H20 bonds.

Condensation

As warm water vapour rises it cools due to altitude. It occurs when saturated air cools down below the dew point - Clouds are atmospheric stores.

Dew Point

The point at which the air can no longer absorb any more water.

Precipitation

Water that falls from the sky - rain, sleet, snow, hail

Groundwater

When the water hits the Earth some of the water infiltrates into the soil and percolates into the rocks. Water stored beneath the surface.

Saturated

Means holding as much water or moisture as can be absorbed - prevents infiltration = increased surface runoff.

Percolation

Water movement through deep soils and rocks

Water Table

The upper surface of the zone of saturation

Stem flow

The flow of interception water down the trunk or stem of a plant.

Global Atmospheric circulation

the world-wide system of winds by which the necessary transport of heat from tropical to polar latitudes is accomplished

Fossil water

A non-renewable store of water - an ancient body of water that has been contained in some undistributed space, typically underground.

Fresh water

Most is located in ice caps and glaciers, a smaller part is in groundwater.

Hydrosphere

All the water at and near the surface of the earth, 97% of which is in oceans

The water balance / budget

The balance between inputs and outputs. - Affects how much water is stored in a system.

The formula = Precipitation (P) = stem-flow (Q) + Evapotranspiration (E) +/- chnages in the storage (S)

River discharge

(m3/s) The volume of water passing a specific point in a given time.

potential evapotranspiration

The amount of water that could be evaporated or trans pirated from an area assuming there is sufficient water available

River regimes

They indicate the annual variation in discharge of a river and result from the impact of climate, geology and soils. - They are affected by the amount of precipitation and outputs.

Orographic rainfall

rainfall produced when a moving moist air mass encounters a mountain range, rises, cools, and releases condensed moisture that falls as rain

Frontal rainfall

The mass of warm air meets the colder air and rises over it (since cold air is heavier) the rainmaking process then occurs.

Throughfall

Water dripping onto other leaves.