Chapter 6 - Managing Water Supplies

Global Water Distribution

• Salt water in oceans

• Surface fresh water

  • Ice sheets, glaciers, lakes, rivers, swamps, marshes, permafrost

• Sub-surface, freshwater

  • Soil moisture, ground water, permafrost

• Atmospheric water

Water Security- the ability to access enough clean water to maintain adequate standards of food and manufacturing of goods, adequate sanitation and sustainable health care.

Global Human Water Use

• Industrial

  • Power plants, metal/plastic manufacturing

• Municipal

  • households (toilet, shower, drinking water)

• Agriculture

  • water for livestock, irrigation water for crops

Causes of Water Insecurity

Climate change, including changes in rainfall, natural disasters, droughts and flooding.

Pollution Events

Surface Pollution

• Domestic waste - sewage and grey water (waste water from baths, sinks, washing machines, and other kitchen appliances)

• Industrial waste with heavy metals and carcinogenic chemicals

• Agricultural chemical and fertilizer run-off - causes eutrophication

Groundwater pollution

Groundwater is clean because porous rocks act as a filter for particles, but due to pollution these rocks can have a high concentration of iron, fluoride, uranium or arsenic, which contaminate it.

Pollutants of groundwater come from

• leachate from landfills

• septic tanks

• storm water drains

• injection wells from fracking for natural gas, fracking for oil pushes toxic chemicals deep into the ground.

• In coastal areas, over abstraction of water from aquifers can lead to salt water intrusion: the movement of saltwater into freshwater aquifers

Population Growth

• As a population increases, demand does too for agricultural and industrial usage.

• Greater population = more waste

• Increased population can result in over abstraction of water from aquifers which drops water tables and makes them harder/more expensive to access.

  • Impacts flora and fauna in the area because trees won’t reach them and animals don’t have access during times of low rainfall.

• Changes in land usage including deforestation and urbanization

  • Forest and wetlands used to act as natural water reservoirs are replaced with urban landscapes that do not allow water to infiltrate the solid and recharge groundwater supplies.

  • Groundwater in urban areas is more likely to be contaminated so urban populations are at risk of becoming reliant on treated water supplies.

Causes of Water Insecurity Cont.

Water Conflict- conflict between groups, regions, or countries over access to water.

• International competition over water sources - when the river crosses international borders

• Inequality of availability between water-rich and water-poor regions

  • People in LICs are less likely to have access to clean drinking water than those in HICs.