A2 Geography - Unit 2 - Water Conflicts

Water is a fundamental need to society. Growing demand and diminishing supply indicates a global deficit, creating conflict. However, it is actually the distribution of water which causes these problems. The gap between those with and without enough water to meet their demands can be illustrated through the development gap.

Types of Flow

• Flows - movement of water from one place to another
   
• Blue Water Flows - visible part of the H.C. - surface flows and then recharging aquifers

• Green Water Flows - water intercepted, stored and released by vegetation through evaporation and transpiration

• Grey Flows - polluted water

• Groundwater Flow - movement of water underground if not absorbed by rocks 

Trends in water demand and supply make the future insecure and uncertain. 

Processes

• Inputs - process of water being made accessible, i.e evaporation from ocean

• Outputs - process of water moving back through H.C. i.e. pptn

• Evapotranspiration - evaporation of intercepted water

• Percolation - water absorbed by underground rocks resulting in ground water flow

• Pptn - clouds releasing their stores

• Infiltration - absorption of pptn by permeable surfaces

Geology

• impermeable rock --> high drainage density
• permeable rock --? water seeps into aquifer stores

• Closed System - how the H.C continues = water supply that's natural and everlasting
• Stores - areas that store water - clouds etc
• Water Stress - occurs with less than 1700m³ /person/year
• Water Scarcity - occurs with less than 1000m³ /person/year
• Physical Scarcity - areas/regions where 75% of rivers flow is being used (above ground)
• Economic Scarcity - no financil means to access blue water flows (infiltrated through groundwater flow)
• Water Poverty Index, WPI - countries scored put of 20 on five parameters - max score 100.
  Scored on resources, access, capacity, use and envrionment.
• Factors for Water Sharing  - natural factors, social + economic needs, downstream impacts, dependency, prior use and efficiency
• Helsinki Rules  - General agreement that environmetnal treaties myst have 'equitable use'/ 'share' and these are applied to whole drainage basins not just single coutntries

• Sewage Disposal - By 2020, in developing countries, this is expected to cause 135 million deaths
  --> Typhoid and Cholera are common
  - UK - 1400 million litres of sewage to rivers daily
  Citarum, West Java - carries waste of 9 million people
• Chemical Fertilisers - can contaminate groundwater flows and rivers. Sewage and fertilisers add nutrients to river, resulting in increased growth of algae causing eutrophication
  - Yucatan, Mexico - high levels of nitrates in groundwater
  - Gulf of Mexico - high levels of algae
• Industrial Pollution - 400 billion tonnes of industrial waste generated per year in the world
                           --> chemicals and heavy metals put into water
  - N.E. China + Citarum river, W. Java, Indonesia, carry waste of hundreds of farms and factories
• Dams  trap sediment, reduce floodplain fertility and flow of nutrients from river to sea#
• - damage coastal fish stocks; sediment change can kill fish and impact the ecosystem
  - Aswan Dam, River Nile + 3 Gorges Dam, China
• Overabstraction of Water - removed for irrigation/drinking
  - if too much removed, in arid areas, water will not return
     - Bangladesh + Pakistan
  - can lead to salt water incursion + salinisation - wells / coast
    - Californian coastline