4.02 Access to Fresh Water

Access to Fresh Water

The Global Water Crisis

  • Water security refers to the capacity of a population to ensure sustainable access to adequate and acceptable quality water that supports livelihoods, human well-being, and socioeconomic development while protecting against water pollution and disasters, and preserving ecosystems in a stable climate.

The Water Crisis

  • Approximately 80 countries and 40% of the world’s population face constant threats from lack of water.

  • Water demand doubles every 20 years, exacerbated by population growth.

  • Water-rich countries often mismanage resources through waste or pollution, while poor countries struggle with polluted water supplies.

  • Securing water access is essential for societal development.

Water Risks 1

  • Over 840,000 people die each year from water-related diseases.

  • In Less Economically Developed Countries (LEDCs), waterborne diseases are a primary cause of death.

  • 750 million people lack access to safe drinking water, and 1.42 billion live in high-water vulnerability areas..

  • Women and children globally spend 140 million hours per day collecting water.

Projected Water Stress

  • By 2025, 2/3 of the world’s population may face severe water stress, particularly in Africa, the Middle East, and South Asia.

  • Rivers are drying up and groundwater is being depleted faster than it can be replenished.

  • Potable water is defined as water that is safe to drink and free from contamina nts.

Increasing Demand and Unequal Access

  • Population growth and rising per capita water use are straining supplies.

  • Over 60% of the world lives in regions receiving only 25% of global annual precipitation.

  • Arid regions cover 40% of land but receive only 2% of precipitation.

Variations in Water Use

  • There are significant differences in water usage between More Economically Developed Countries (MEDCs) and LEDCs.

  • In the US, irrigation uses 80% of water in the West but only 6% in the East.

  • Irrigated farming accounts for 70% of global water consumption, indicating that water conservation in agriculture could yield substantial benefits.

Factors Influencing Drinking Water Access

  • Physical factors: precipitation levels, seasonal distribution, storage capacity, and evapotranspiration rates.

  • Human factors: national wealth, infrastructure investment capabilities, population distribution, and contamination issues.

Definitions of Water Scarcity

  • Water-stressed areas have less than 1700 m3 of water supply per person per year; water-scarce areas have less than 1000 m3.

  • Physical water scarcity is due to limited access to water resources.

Examples of Physical Water Scarcity

  • Egypt imports over half its food due to insufficient water for domestic agriculture.

  • The Murray-Darling Basin and Colorado River Basin have faced severe water shortages due to overuse.

Economic Water Scarcity

  • Economic water scarcity occurs when financial constraints prevent access to adequate water sources.

  • Major factors include rising population, increasing wealth leading to greater usage, climate change causing aridity, and pollution.

Depleted Aquifers

  • Aquifers are critical for providing drinking water but face significant depletion and contamination.

  • Issues include falling water tables, saline intrusion from seawater, and pollution from sewage.

Water Pollution

  • Water pollution renders sources unfit for use from diverse sources: agricultural runoff, industrial discharges, and untreated sewage.

  • Nearly 90% of sewage in LEDCs is disposed of improperly, contaminating freshwater sources.

Pollution Concerns in MEDCs

  • There is growing concern regarding pharmaceutical residues in water, which may pose risks to vulnerable populations.

Climate Change Impacts

  • Climate change can lead to reduced precipitation, increased evaporation, and higher risks of flooding, further stressing water supplies.

Enhancing Water Supplies

  • Several methods exist for enhancing water supply, each with pros and cons, including reservoirs and distribution networks.

Dams and Reservoirs

  • Dams significantly increase water consumption and impact river basins worldwide, although most prime locations are already developed.

Impacts of Dams

  • Dams can cause sediment trapping, affect aquatic species, and alter ecosystems.

Wells and Bore Holes

  • Wells provide a large percentage of drinking water but are vulnerable to contamination.

Water Redistribution

  • Water networks allow for redistribution, primarily in MEDCs, but have limitations in LEDCs due to infrastructure constraints.

Desalination

  • Widely practiced in arid regions, desalination can provide fresh water but is costly and energy-intensive.

Pros and Cons of Desalination

  • Advantages: does not affect river water levels.

  • Disadvantages: high costs and ecological impacts on marine ecosystems.

Replenishing Aquifers

  • Aquifer replenishment can be achieved through spreading water across land or injecting directly into aquifers.

Cloud Seeding

  • Cloud seeding involves modifying cloud development to enhance precipitation, raising environmental and economic concerns.

Conservation Measures and Investment

  • Low water costs in MEDCs discourage conservation, while higher prices could drive sustainable practices but may burden lower-income citizens.