Water Resources
• The hydrologic cycle constantly redistributes water• Total: 370 billion billion gallons
• 500,000 km3 evaporates from oceans; 90% return
• Solar energy drives the cycle
• Water supplies are unevenly distributed• Global atmospheric circulation
• Proximity to water sources
• topography
Major Water Components
• Oceans hold 97% of all water• Regulates our planet’s atmosphere
• Glaciers, Ice, Snow = most surface fresh water• Quickly disappearing
• Groundwater stores large resources
• Rivers, lakes, wetlands = cycle quickly• Small, constantly need to be replenished
• Wetlands = vital
• Atmosphere = among the smallest of compartments
Water Availability and Use
• Renewable water is made up of surface runoff and infiltration
• While readily accessible water supplies are large, water scarcity still occurs when there is a great demand for water or poor water quality
• Droughts can be caused by the introduction of domestic animals, and is exacerbated by land use
• Water use divided into 3 parts: agricultural, domestic, and industrial, with agricultural having the greatest consumption
• Irrigation can be insufficient, with much water being lost through evaporation and run off (drip irrigation is a much better solution)
Water Use Cont. and Freshwater Shortages
• Wealthy countries use far more water than developing countries, which usually lack access to clean water
• Water shortages are usually caused by natural deficits, over consumption by agriculture or industry, and inadequate funds for purifying and delivering good water
• Ground water is being depleted by diversion projects, dams and canal systems, which have damaging effects on the environment
• Sedimentation and climate change affect reservoirs greatly
• Eventual lack of resources may lead to fights over water supplies
Conserving
• Getting by with less water• Farmers are starting to follow the “land bank” plan, they agree to a 10-25%
reduction in their water usage. Due to the depleted amount of water availability this plan benefits farmers in a way that their access to water is not shut off completely.
• Increasing the water supply• Farmers used to pay “rain makers” in an effort to save their crops
• “rain makers”- person who attempts to make rain fall through rituals or scientific techniques (via seeding clouds- dry ice or KI particles)
• What we can do now!• Shorter showers, stopping leaks, switch to drought resistant lawns.