Chapter Eleven: Water

Section One: Water Resources The Water Cycle

Section One: Water Resources Global Water Distribution 71% of Earth’s surface is covered in water, but only 3% of that is freshwater And 77% of that freshwater is frozen in glaciers and the polar ice caps Surface Water Surface Water: freshwater on Earth’s land surface River Systems and Watersheds

Section One: Water Resources River Systems River system: a flowing network of water moving across land Water comes from melting snow and rain Watersheds Watersheds: the area of land that is drained by a river

Section One: Water Resources Groundwater Groundwater: water beneath the Earth’s surface in sediment and rock formations Water table: the area where rocks and soil are saturated with water Aquifers: the underground formation that contains groundwater Porosity: the percentage of the total volume of a rock that has spaces or pores Permeability: the ability of rock or soil to allow water to flow through it

Section One: Water Resources

Section One: Water Resources Groundwater The Recharge Zone An area of the earth’s surface from which water percolates ( or penetrates) down into an aquifer Pollution can enter the water system through the recharge zone Wells Where a hole is dug or drilled to reach groundwater If the water table falls, the well will dry up

Section Two: Water Use and Management Residential Water Use

Section Two: Water Use and Management Residential Water Use Water treatment Most water must be treated to be potable, or safe to drink Treatment removes elements which can be poisonous to humans Also removes pathogens, which are organisms that cause illness or disease

Section Two: Water Use and Management Industrial Water Use and Agricultural Use Industry Uses 19% Most used to cool power plants Agriculture Uses 67% Irrigation is the main usage

Section Two: Water Use and Management Water Management Projects Water Diversion Projects Supplies water to dry regions by building canals Dams and Reservoirs Dam: a structure built across a river to control the river’s flow Reservoir: an artificial lake formed by a dam

Section Two: Water Use and Management Water Conservation In Agricuture Drip irrigation systems In Industry Recycling and cooling of wastewater At Home Water saving technology Ex. Low flow toilets and shower heads Water lawns at night

Section Two: Water Use and Management Solutions for the Future Desalination The process of removing salt from salt water Transporting water

Section Three: Water Pollution Water Pollution: the introduction of chemical, physical, or biological agents into water that degrade water quality and adversely affect the organisms that depend on the water Point Source Pollution Pollution discharged from a single source Example: leaking septic tanks Nonpoint Source Pollution Comes from many different sources that are often difficult to identify Example: oil and gasoline from boats

Section Three: Water Pollution Wastewater Water that contains waste from homes or industries Treated to make it clean enough to return to the rivers and lake Sewage sludge: the solid material that remains after wastewater treatment Usually burned and then buried

Section Three: Water Pollution Artificial Eutrophication Eutrophication caused by humans Inorganic nutrients such as nitrogen and phosphorus enter the water through sewage and runoff Can come from farms, homes through detergents Causes algal blooms

Section Three: Water Pollution Thermal Pollution The temperature of a body of water increases Can be caused by power plants using the water in their cooling systems and discharge warm water Causes huge fish kills Decreases oxygen levels in the water

Section Three: Water Pollution Groundwater Pollution When pollutants go down into the earth and contaminate the water under the ground Caused by pesitcides, herbicides, chemical fertilizers, and petroleum products Leaking underground tanks

Section Three: Water Pollution Ocean Pollution Ships can legally dump wastewater and garbage in some parts of the ocean Most pollutants come from activities on land Oil spills

Section Three: Water Pollution Water Pollution and Ecosystems Causes immediate damage and gradual damage Biomagnification Buildup of pollutants at higher levels of the food chain

Section Three: Water Pollution Cleaning Up Water Pollution Clean Water Act of 1972 Cuyahoga River Fire Marine Protection, Research, and Sanctuaries Act of 1972 Oil Pollution Act of 1990