Module 28 Human Use of Water Now and in the Future

Water is used For Agriculture

water footprint: the daily per capita use of fresh water

  • around the world, water is used for agriculture more than anything else

  • The daily use of water per capita varies dramatically around the world

Irrigation

  • technological advances have made water use for crops more efficient

    There are 4 types of irrigation:

    1. Furrow: a trench that is flooded with water

      • oldest

      • prone to evaporation

    2. Flood: the entire field is flooded with water

      • potentially water-logging

    3. Spray: an apparatus sprays water across a field

    4. Drip: a slow dripping hose is laid on or buried beneath the soil (prevents weeds and is the most efficient)

Hydroponic agriculture

Hydroponic agriculture: The cultivation of plants in greenhouse conditions by immersing roots in a nutrient-rich solution

Hydroponic is a more expensive alternative to irrigation but has advantages:

  • Requires little or no pesticide use

  • Uses 95% less water than traditional irrigation

  • Crops can be grown year-round

Industrial Water Use

industrial uses that require water:

  • generating electricity

  • cooling machinery

  • refining metals

  • making paper

Household Water Use

  • household water use accounts for 10% of all water use in the United States

  • Per capita house water use varies dramatically among nations

  • Developed Nations tend to use more water than developing nations

  • most water used indoors is used in the bathroom

Water Conservation and Technologies

Tiered water-pricing systems: A water allocation system that charges rates that increase with the amount of water consumed

Xeriscaping: A style of landscaping that removes water-intensive vegetation from lawns and replaces it with more water-efficient native landscaping

  • planting native plants

The Future of Water Availability

  • water ownership and water rights have created conflicts

    Gray water: Wastewater from baths, showers, bathrooms, and washing machines

    Contaminated Water: Wastewater from toilets, kitchen sinks, and dishwashers