Presentation on theme: "Water lot of water? What physical and human factors affect water supply? Is supply and demand balanced in different parts of the world?"— Presentation transcript:
1 Water lot of water?What physical and human factors affect water supply? Is supply and demand balanced in different parts of the world?
2 Human influences on water supply and demand Disruption of water cycleLand use changes affect interception + infiltration + surface storage;Eg urbanisation, deforestationWater abstraction affects ground water storage, and can create salinisation and salt water incursionFlood management + dam construction affect channel flow + storageBy Quantity( adding to or abstracting) or Quality(pollution)Humans affect the hydrological cycle at many points of flows and storage:
3 Graphs p 34 and 35 Pearson How is water used on a worldwide scale? How is water used in the UK?
4 Blue water flow is the visible part of the hydrological system: surface flows and then recharging aquifersGreen water flow is water intercepted, stored in soil and released by vegetation by evaporation and transpirationGrey water is polluted waterSupply can be from:Surface sourcesgroundwater sourcesIn the UK 2/3 of supply is from surface and 1/3 from groundwater, with regional variations.Freshwater is effectively a finite resource since only about 1% of freshwater is easily available for human use.The water footprint indicates how much is required by consumers- and in an increasingly globalised world, the footprint of someone in a country like the UK will not be just local as so many products using water will have been produced elsewhere!
5 The cost of everyday items ….in litres of water.One sheet of A4…One slice of bread…One apple..One cup of coffee..One pint of beer..One pair of leather shoes..One packet of mixed saladOne bag of crisps..One litre of milk..One cotton tee-shirt..One pair of jeans..One 100g bar of chocolate..One glass of wine..
6 The cost of everyday items ….in litres of water.One sheet of A4…10One slice of bread…40One apple..70One cup of coffee..140One pint of beer..75One pair of leather shoes..16,600One packet of mixed salad..50One bag of crisps..185One litre of milk..1000One cotton tee-shirtOne pair of jeans..10,850One 100g bar of chocolate..2400One glass of wine..120
7 Some key definitions p 61 Oxford and p 37 Pearson Watershortagelow level of water supply relative to basic needs.measured by annual renewable flows (in cubic metres) per head of population, or the number of people dependent on each unit of waterstressoften taken as less than 1700m3 per person per yeargrowing conflict between users and competition for waterdeclining standards of reliability and serviceharvest failures and food insecurity.scarcitysupply of water per person falls below 1000m3/yearan imbalance of supply and demanda high rate of use compared to available supply, especially if the remaining supply is difficult or costly to tap.Physicalwaterreached when 60% of river flows are diverted for agricultural, industrial & municipal purposes; globally over 75% is now usedPhysical water scarcity is shown by:Severe environmental degradationDeclining groundwater and water allocation which favours some groups over others.Arid and semi-arid areas are most at riskEconomicwhen less than 25% of rivers are used, and there is abundant supply potential: water does not reach the poorest peopleThis is often due to political reasons and conflict: easiest to solve by low technology solutions: small dams, water harvesting from roof tops etc. It is targeted by NGOs like Water AidDomestic
12 Water Supply In India Monsoon Climate High pressure due to descending airMonsoon ClimateDue to the movement of the ITCZLittle supply Dec – MayMonsoon June - OctBrahmaputraGangesIndus2. Changing Discharge in the Ganges, Indus and Brahmaputra.This varies seasonally due to the Monsoon and snow melting in the Himalayas3. GeologyAquifers in the North = good water supplyLow Pressure due to the position of the ITCZ
13 Cherrapunji’s (in India)missing water? LO: Why can’t we have water everywhere?Why?Water scarcity isn’t just the fault of people
14 What are the physical and human reasons that water is an issue in Cherrapunji, India? Thinking
15 Watch the clip and read the article…in pairs Complete a table of the physical reasons and human human reasons why water supply in Cherrapunji has changedHighlight where there are potential overlaps between the two columns. Decide which of the reasons is the strongest by scoring them in order (1 for most important, X for least important. The strongest reason gets the lowest score)
16 Factors affecting Cherrapunji Physical geographyMonsoon climate – variabilitySaturation of ground – imperviousClimate change?Human GeographyLack of dams – can’t harness variable supplyAquaculture, NOT agricultureOverpopultion
17 YemenSanaa, capital of Yemen, has no renewable water. At 2,300m above the sea, the city cannot use desalinated water and the only solution could be to move the capital.Read p 38 Pearson
18 UK water supplyLet’s examine the reasons for the variation in water demand and supply in the UK.
19 Estimated changes in demand for water 1990 - 2021 Work out the estimated changes in different regions of the UKShow this on the map after discussing with your partnerWhat are the advantages / disadvantages of the methods used?
20 Areas of water surplus /water deficit Using a range of Atlas maps and information, annotate the outline map of the UK to help identify the reasons why there is a water surplus /deficit in the areas identified. Add as much detail as you can around your map.
21 Water resources and climate change? P 38 Pearson
22 The key players who affect the supply and demand for water?
23 The key players who affect the supply and demand for water? Water companiesGovernments – national and state/local authorityUN, WTO and TNCSAgricultureIndustry/businessRecreation/tourismDomestic usersCharitiesNature conservation
24 California p 52-59 Oxford Why are we doing this case study? ‘With reference to differing examples , explain how differing stakeholders views could lead to water conflict’ (15)‘Referring to examples, assess the potential for water conflict in areas where demand exceeds supply’ (15)California p Oxford
25 Explain the physical controls on the supply of fresh water in California (think about the climate, river systems and aquifers etc )How is human activity affecting the water availability in California?What are different key players likely views on the water issues in California?What are the environmental implications of supplying water to California?What are the economic implications of supplying water to California?IN DETAIL
26 Why will conflict arise here ? 7 states covered :Wyoming / ColoradoNew Mexico / ArizonaCalifornia / NevadaUtahWhy will conflict arise here ?Las Vegas 1.8 millionColorado1 of the bread basket statesHoover DamMojave DesertGlen Canyon DamPhoenix – 1.5 million residentsSalt water :Pacific Ocean and gulf of California
27 History of the Colorado Basin Colorado Compact 1922, allocated the water rights between the different states1920’s ‘law of the River’ divided the river into the Upper basin states, who had responsibility to supply the lower statesOver time new treaties have been signed and Mexico has also been involvedNow there is a ‘giant plumbing system’, with more than 10 major dams to give water to over 30 million peopleLots of the treaties were established in the 1920’s, since then population, industry and climate here have all changed
28 Stakeholder and what they think including specific detail Complete the Conflict matrix, but also put in their opinions in detail in the first columnStakeholder and what they think including specific detailFarmersCity dwellersEnvironmentalistsIndigenous groupsMexican PeopleUS federal GovCity DwellersEnvironmentalist and recreationistsIndigenous GroupsUS federal Government