- Slides: 50
CHAPTER 14 Water Resources
Looking for Water. . . in the Desert • The 2300 -kilometer Colorado River once flowed deep and wide across the Southwest to Mexico’s Gulf of California. • Since the Colorado River Compact, in 1922, seven states— Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming—have relied on the river’s water for human use. • Today, drought, dams, and diversion have caused the once-raging Colorado River to run nearly dry. • Las Vegas, Nevada city officials have turned to an unlikely source for water—the desert. Their proposal to mine groundwater from beneath a scenic area of the Great Basin Desert is controversial. Talk About It Is the human need for fresh water reason enough to mine in an area that may threaten area ecology? What other ideas might states in the Colorado River Basin try?
Lesson 1. 1 Earth: The Water Planet Although the vast majority of Earth is covered in water, one in eight people lacks access to clean freshwater.
Lesson 14. 1 Earth: The Water Planet Where Is Our Water? • Fresh water is both a renewable resource and a limited resource. Did You Know? If all Earth’s water were in a two- liter bottle, only about two capfuls would be fresh, liquid water. • Earth’s fresh water is distributed unequally. How much water people use depends on where they live and the time of year.
Lesson 14. 1 Earth: The Water Planet Surface Water • Surface water includes still bodies of waters and river systems. • Watersheds include all of the land area that supplies water to a river system. Watersheds of the U. S. Did You Know? The Mississippi River Basin covers 3 million square kilometers (1. 2 million sq mi), making it the third largest watershed in the world. It drains 41% of the land area of the contiguous US. • Every waterway defines a watershed.
Lesson 14. 1 Earth: The Water Planet Groundwater • Groundwater seeps through the soil and becomes contained in underground aquifers. • Aquifers are permeable layers of rock and soil that hold water. • The water table separates the zone of saturation from the zone of aeration. An Aquifer Did You Know? The average of groundwater is 1400 years. Groundwater recharges very slowly.
Lesson 14. 1 Earth: The Water Planet Groundwater • Aquifers release 1. 9 trillion L (492 billion gal) of groundwater to the surface each day via springs, geysers, and wells. Old Faithful, a well-known geyser in Yellowstone National Park, shoots groundwater over 100 feet into the air many times a day.
Lesson 14. 2 Uses of Fresh Water One third of all the people on Earth are affected by water shortages.
Lesson 14. 2 Uses of Fresh Water Using Surface Water • Most freshwater used in the U. S. is surface water. • Surface water is diverted by canals and dams. • Drought and overuse have caused significant surface water depletion. Did You Know? The Aral Sea was once the fourth largest body of fresh water. Aral Sea, 1997 Aral Sea, 2009
Lesson 14. 2 Uses of Fresh Water Using Groundwater • 68% of groundwater in the U. S. is used for irrigation, most of which is very inefficient. • Groundwater mining – withdrawing groundwater faster than it is replaced. Water becomes a nonrenewable resource. Ex. Las Vegas – unsustainable water use • When groundwater is depleted, the falling water tables can cause cities to sink, and undrinkable saltwater to move into the depleted aquifers.
Lesson 14. 2 Uses of Fresh Water How We Use Water • Three main uses of fresh water include: • Agricultural 70% • Industrial 22% • Personal 8% Did You Know? The average American uses 250 L or 60 gallons of fresh water a day for personal uses, such as bathing and brushing teeth.
Agriculture • Accounts for 70% of all water usage
Agricultural Practices that are Water Unsustainable • Leaky irrigation • Wasteful field application methods • Cultivation of “thirsty” crops Center pivot irrigation in Nebraska
Agriculture • Do we need to be growing crops and livestock that require so much water? ? ? ? • For example 58% of the world’s cropland is used to grow some of the thirstiest drops: • Cotton • Sugar cane • Wheat • Rice
Is California Nuts? ? ? 1 Almond = 1 Gallon of Water Almond growing uses 10% of drought stricken California’s ag water 2 out 3 nuts are exported – so “our” water goes elsewhere – interferes with the water cycle 4 billion in nuts; 11 billion in related industries 104, 000 jobs Save the environment – Save the jobs (Food)
Then and Now • http: //abcnews. go. com/Politics/california-gov-jerrybrown-defends-farms-water-warns/story? id=30106594
Livin’ in the Land of Cotton • What did your T-shirt Cost you? What did it cost the Environment? What did it cost Others?
What’s your Beef?
Water problems resulting from Ag • Depletion/ Loss of quantity – • Water used for agriculture is lost to other uses • Water is moved from its location to elsewhere • Degradation/ Loss of quality • Agricultural practices pollute the very water resources they rely on • Surface run off from irrigation causes soil erosion, as well as adding fertilizers, pesticides, fecal waste to water bodies
Industry Industrial uses accounts for 22% and include: • The manufacture of goods requires water as a solvent to dissolve and carry away waste
Coolant for manufacturing and power plants • Water used piped through manufacturing and power plants to cool off machinery
Oil and Gas Refining
In Stream Uses • Water isn’t removed from its sources but used in place • Hydroelectric Plants
• Water Impoundments - Dams and Reservoirs
• Transportation / Shipping
WARNING!! • 1 out of every 3 people in the world are regularly affected by water shortages that don’t allow them a steady, dependable source of water on a daily basis. • Data shows that OUR current rate of freshwater use is unsustainable in much of the world INCLUDING the United States. What can be done – What can we personally do? Why should we care when we still can turn on our taps and get water? Wait…have you been in Ktown lately?
Lesson 14. 2 Uses of Fresh Water Solutions to Freshwater Depletion • Increase supply: • Desalination: “Making” fresh water by removing salt from saltwater. • VERY EXPENSIVE • Decrease demand: • Agricultural: Dripirrigation, climateappropriate plants • Industrial: Waterconserving processes, recycling wastewater to cool machinery. • Personal: Xeriscaping, water conservation, Consumer choices – food, goods Desalination
Water Footprint • "Water footprint" is a measure of water use, and can be calculated for individuals, businesses, cities, and countries. • It includes direct water use (such as for drinking and cleaning) as well as indirect use (the water required to produce goods and services). This indirect water use is described as ‘virtual’ water.
Xeriscaping • Landscaping and gardening methods that reduce or eliminates the need for additional watering beyond what Mother Nature provides. • Benefits: • Saves water: In N. A. over 50% of residential water used is applied to landscape and lawns. Xeriscape can reduce landscape water use by 50 - 75%. • Saves money
Traditional Landscaping * Plants require extra watering beyond what nature provides * Methods of applying water cause it to evaporate faster – sometimes before it even hits the ground! *Plants that require a lot of water are often grown in areas that are very sunny and hot which requires more watering or where water is limited.
Pick the right Plants • Use drought-resistant plants. Usually these plants have leaves which are small, thick, glossy, silver-grey or fuzzy - characteristics which help them save water.
Plant Placement • South and west facing exposures receive more direct sun and heat – use plants which require little water. • North and east facing slopes are cooler and moister
Mulching • Cover the soil's surface around plants with a mulch, such as leaves, coarse compost, pine needles, wood chips, bark or gravel. Mulch helps retain soil moisture and temperature, prevent erosion and block out competing weeds. Organic mulch will slowly incorporate with the soil
Soaker Hoses and Drip Irrigation
Lesson 14. 3 Water Pollution 3, 800 children die every day from diseases associated with unsafe drinking water.
Lesson 14. 3 Water Pollution Types of Water Pollution • Point-source pollution: From a discrete location, like a factory or sewer pipe • Nonpoint-source pollution: From many places spread over a large area, such as when snowmelt runoff picks up pollutants along its path Point source oil pollution Oil after a spill, Trinity Bay, Texas
Lesson 14. 3 Water Pollution Nutrient Pollution THE PROCESS OF EUTROPHICATION Nutrients build up in water. Algae and aquatic plant growth increases. • Excess phosphorous and other nutrients in the water is nutrient pollution. • Eutrophication occurs naturally. • Nutrient pollution cause cultural eutrophication. Organisms die. Decomposition requires oxygen. Dissolved oxygen levels decrease.
Lesson 14. 3 Water Pollution Toxic Chemical Pollution • Occurs when harmful chemicals are released into waterways • Can be organic or inorganic • Harms ecosystems and causes human health problems
Lesson 14. 3 Water Pollution Sediment and Thermal Pollution • Sediment pollution: • Unusually large amounts of sediment that change an aquatic environment • Sediment pollution results from erosion. • Can degrade water quality, cause photosynthesis rates to decline, and disrupt food webs • Thermal pollution: • A heat source that raises the temperature of a waterway • Heated water holds less oxygen.
Lesson 14. 3 Water Pollution Biological Pollution • Biological pollution occurs when pathogens enter a waterway. • Biological pollution causes more human health problems than any other form of water pollution. • Water treatment reduces biological pollution. Cholera bacteria Did You Know? Giardiasis is the most common form of waterborne disease in the U. S.
Lesson 14. 3 Water Pollution Groundwater Pollution • Sources of groundwater pollution include natural sources, surface pollutants leaching through soil, and leaky underground structures. • Chemicals break down more slowly in groundwater than in surface water. • Most efforts to reduce groundwater pollution focus on prevention. Did You Know? The EPA repairs and replaces leaky underground gas storage tanks to reduce groundwater pollution. Over the last 25 years, over 1. 7 million tanks have been repaired or replaced. Acid drainage from a coal mine
Lesson 14. 3 Water Pollution Ocean Water Pollution • Oil pollution in the ocean comes from many widely spread small sources. Natural seeps are the largest single source. • Ocean organisms bioaccumulate mercury pollution. A 2004 oil spill off the Alaskan coast Did You Know? According to the U. S. Oil Pollution Act of 1990, by 2015, all oil tankers in U. S. waters must have double hulls to help prevent against leaks. • Nutrient pollution cause red tides.
Lesson 14. 3 Water Pollution Controlling Water Pollution • Government regulation decreases water pollution. • The Clean Water Act Lake Erie • Set water pollution standards • Required permits to release point-source pollution • Funded sewage treatment plant construction Did You Know? The Great Lakes show that humans can change their ways and clean up trouble spots. In the 1970 s, Lake Erie was declared “dead” but is now home to some flourishing species, especially the walleye.
Lesson 14. 3 Water Pollution Water Treatment • Drinking water is treated to remove pollutants before humans consume it. • Wastewater is treated to remove pollutants before humanused water is released back to the environment. Septic systems are the most popular method of wastewater disposal in rural areas of the U. S.
https: //www. utwente. nl/touch/en/2012 -10/waterfootprint/