Supply of Water

							What physical factors determine
     the supply of water?
       G4 Water Key Idea 2.1
Rivers only 2% of surface freshwater
The parts of
the water cycle
Global values of the water cycle
Climate determines where rain falls – Highs and Lows
Freshwater availability varies at different scales
Continent population and fresh water
Upland Wales – temperature and rainfall
Craig Goch
Wales - a
good
reservoir site
– why?
London SE England – Temperature and Rainfall
England and Wales – matching supply and demand.
Water Transfer – proposal (controversial)
Water Balance
Botswana – Rainfall Total, seasonality, variability
India –
climate, river
discharge,
aquifers
Relief – river
basins
                                                           Climate
                                                           Change –
                                                           ultimately
                                                           reduced
                                                           river
                                                           flows in
                                                           some
                                                           areas




Global warming will melt most Andean glaciers in the next 30
years, scientists say, threatening the livelihood of millions of
people who depend on them for drinking water, farming and
power generation.
Aquifers and
groundwater in
the UK
Thames Basin - artesian
See pie chart c).
Water supply is not always top quality. Human impact.
Human impact on supply. Lake Chad.
Water scarcity – physical and economic.