Water 1
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what % of earths water is freshwater?
• 5% - only a small fraction of which is available
what is Mesopotamia and where was it located?
ancient civilisation 3000BC located between Tigris and Euphrates rivers - capital was Babylon Babylons hanging gardens - wear v important
why do people settle near rivers?
• its essential for development • river floods and enriches the soil with silt and minerals • bathing • washing • transport • worship
what is the water footprint
measure of humanity appropriation of fresh water in volumes of water consumed/polluted
average consumption of water
3-5 litres of drinking water/day 100-400 including washing and sanitation/day
what’s the big issue behind production/the indirect effects
agriculture, water and industry use lots of water e.g. one beef burger =10000litres one egg = 200-250litres one slice of bread = 40 litres
what are the 3 water footprints
green, blue, grey
green water footprint
from precipitation stored in root zone of soil and evaporated/transpired by plants. relevant for agricultural, forestry and horticultural products
blue water footprint
sourced from surface or groundwater and either evaporated, incorporated or taken from one body of water and moved to another. irrigated agriculture, industry and domestic water use
grey water footprint
amount required to assimilate pollutants to meet specific water quality standards. point source pollution through a pipe or indirectly due to runoff or leaching
why are there concerns for future
due to climate change, population increase, urbanisation etc
how much of the worlds population will be living in water stressed areas by 2025?
half
in 2015 how much of the population used a safely managed drinking water service, located on premises and available when needed and free from contamination
71% 5.2billion people
how many people lack basic drinking water service
844 million
how are low and middle income countries health care facilities are affected by lack of water
38% lack improved water source 19% don’t have improved sanitation 35% lack water and soap for handwashing
what % of disease in Africa is caused by unsafe water
4-8%
key issues straining future water sources
climate change, growing population, urbanisation, increased water demand per person, contamination of water, changes inland use
future water wars?
as droughts intensify, conflict of who gets water source access is more fraught.
how many incidents invloved conflict and collaboration over shared river basins in 1990-2008
2000
problems with groundwater consumption
much of it comes from fossil aquifers that were last replenished in glacial period 10000-20000 yrs ago thus if we use it all it won’t be recharged in our lifetime - unsustainable
how can we study groundwater
satellites GRACE mission - detects changes in gravity
how much have water levels dropped by in the past decade ?
100feet
what is happening in response to dropped water levels
building of deeper tunnels e.g. under lake mead short term and unsustainable
Las Vegas case study
home to 40mill with 2 mill tourists 4 inches of rain a year most people have pools city now pays $1.50 for every square foot to replace turf with desert landscape