Geography A2 - Water Security

  • Created by: Ellaflies
  • Created on: 29-05-17 18:49

Geography A2 water notes


·         97.5% of the worlds water is in the sea - difficult to use

·         2/3 population only recieve 25% of the rainfall

·         Water gap - MEDCs use 10 times more water than LDCs (More money, more supply and more usage. LDCs dont have the water so it is more expensive)

·         By 2025 half of the population expected to be water vulnerable

·         international rivers
      transboundary groundwater

shared between 2 or more countries

upstream gets dammed

Leads to conflict

·         BRICS/NICS developing - disposable income increases

      Industry needs more water

      want more tech - use more water

·         some people dont have enough clean water

·         Climate change - melting glaciers and little room for LDCs to adapt

·         humans are polluting fresh water 

·         LDCs one of the biggest killers are waterbourne diseases


Physical Factors that influence water supply

·         Climate determines the global distribution of water by means of annual and seasonal rainfall distribution or snowfall

·         Rivers transfer surface water across continents

·         Geology controls the distribution of aquifers which supply underground water


SPC Water, Sanitation and Hygiene : Water Distribution







·        Convectional rainfall

Image result for convectional rainfall









In the Amazon rainforest where the sun is overhead, it has a high angle in the sky which means you get convectional rainfall = 2000mm rain per year

UK = 800/1000mm rain per year.

·        Relief rainfall

Image result for relief rainfall

Areas of Highland, eg: west of the UK

Air warms up and contains little moisture
rain shadow effect (dry conditions)

·        Image result for intertropical rainfallIntertropical




What causes drought?

·         Problem for water supply

·         El Nino in Australia and La Nina in S America

·         Rain Shadow effects

·         Wind From Land

·         High Pressure

How do Humans Interfere with the Water Cycle?

Text Box: Condensation Text Box: Precipitation Text Box: Evaporation Text Box: Transpiration Text Box: Surface runoff Text Box: Infiltration

Image result for water cycle














Human interference


When water turns into vapor and goes up to the clouds

Climate change


Evaporation of water from pores (stomata) of plants


Reduce rainfall

-          Plant trees


Water and ice that fall to the earth’s surface

Climate change


When water is soaked into the ground

Make impermeable surfaces

Surface runoff

Water running offsurface because it is impermeable




Water stored in the ground

Overpump the ground water (salt water incursion) and pollute it

Physical factors affecting water sources  -



·        How rainfall varies globally

·        Regions near to the equator recieve high levels of annual precipitation while some tropical areas suffer reoccuring drought

River systems

·        River flow generally increases downstream as tributaries feed into the main river

·        Though high temperatures can lead to considerable water loss due to evaporation


·        Where rocks underlying river basin are impermeable water will remain


No comments have yet been made