Unit 8 Exam - Chapter 13 Flashcards
How long is the Colorado River?
Flows 2,300 km through seven U.S. states
How many days and reservoirs does the Colorado River have?
14 dams and reservoirs
From where is the Colorado River supplied?
snowmelt of the Rocky Mountains
What four places does the Colorado River supply electricity and water to?
Las Vegas, Phoenix, Los Angeles, and San Diego
Also irrigates crops
What three issues is the Colorado River experiencing?
Very little water is reaching the Gulf of California
System has experienced severe drought since 1999
Lake Mead fell to record low water level in 2015
Freshwater …
One of the earth’s most important forms of natural capital
Used inefficiently and polluted
Low cost encourages waste
Not accessible to many people
Why is access to freshwater a GLOBAL HEALTH issue?
Over 4,000 people die each day from lack of access to safe drinking water - water borne diseases and diarrhea
Why is access to freshwater an ECONOMIC issue?
Water is vital for producing food and energy
Why is access to freshwater an ENVIRONMENTAL issue?
Excessive withdrawal
Why is access to freshwater a NATIONAL AND GLOBAL SECURITY issue?
“Amidst ever-growing geopolitical tensions, economies experience added pressure on precious natural resources. And as water scarcity forces people to seek resources elsewhere, they risk being exploited or harmed as countries react to the increased migratory flows.”
What percent of the water supply in the world is available freshwater?
0.024% of water global supply
Where does freshwater come from?
Groundwater, lakes, rivers, and streams
Hydrologic Cycle
Movement of water in the seas, land, and air
Distributed unevenly
How do humans alter the Hydrologic Cycle?
Withdrawing and polluting water, and causing climate change
Why is there freshwater scarcity?
More than enough renewable freshwater
Unevenly distributed and polluted
Water footprint
Rough measure of all the water an individual uses
Virtual Water
Virtual water is water used indirectly to produce products and food, but is considered part of a person’s water footprint depending on what they consume
Virtual water = Water used to produce food and other products
Where does much of the water from precipitation go?
Seeps underground and into aquifers
What are some of the biggest example of water use in US households?
Washing clothes
Showers
Toilets
Leaks
Faucets
Electric Power Plant Cooking
Irrigation
What do the Nile, Jordan, Yangtze, and Ganges have in common?
Many of the world’s major river systems are highly stressed
How many countries face water scarcity / what is the prediction for the future?
More than 30 countries face freshwater scarcity
Estimate: 60 countries by 2050
What percent of Earth’s land experiences drought?
30% of the earth’s land area experiences severe drought
Research predicts this will worsen
Is groundwater use sustainable?
Groundwater withdrawals are Unsustainable in Some Areas
Groundwater
Groundwater - water under ground - like aquifers
Can drop a well if there’s one under your house - it is legal!
Withdrawing Groundwater : Advantages
Useful for drinking and irrigation
Exists almost everywhere
Renewable if not over pumped or contaminated
Cheaper to extract than most surface waters
Withdrawing Groundwater : Disadvantages
Aquifer depletion from overpumping
Sinking of land (subsidence) from overpumping
Some deeper aquifers are nonrenewable
Pollution of aquifers lasts decades or centuries
Ogallala Aquifer
OVERPUMPED
largest known aquifer
Irrigates the Great Plains
Very slow recharge
Water table dropping
Water pumped 10–40 times faster
than recharge rate
Government farm subsidies result in further depletion
Biodiversity threatened in some areas
Groundwater Depletion : Prevention
Use water more efficiently
Subsidize water conservation
Limit number of wells
Stop growing water-intensive crops in dry areas