Unit 7-Water Quantity/quality Flashcards
(45 cards)
How much of the global water supply is salt water?
97.5%
How much of the global water supply is freshwater but is frozen?
2.5%
How much of the global water supply is freshwater and available as groundwater, soil moisture, water vapour, or surface water? (Lakes, rivers, streams, creeks)
0.5%
**How is water being cycled through the environment and purified?
The hydrologic cycle
-Evaporation, condensation, precipitation, transpiration
Where is water purified in the hydrologic cycle?
During evaporation
We build cities along _____ where discharge from a river cannot be contained
Flood plains
Why are floodplains good for farmers, water, and wildlife?
They clean the water by removing nutrients and sediments
Floods leave behind nutrient rich soil for farmers
They recharge aquifers used for drinking water and irrigation
Supports wildlife
What happens when floodplains are altered? What is put in place?
Dams and levees to reduce the risk of flooding which allows for cities to be built around them
**What are some flood management strategies?
Dams, levees
Floodgates can be installed along levees so farm fields are flooded instead
Uses of freshwater (%)
Human residential consumption
Human commercial consumption
Agriculture
Industry
8%
2%
70%
20%
What helps increase crop production but has a heavy demand on surface and ground waters?
Irrigation
What does irrigation lead to?
Salinization
**What is salinization?
Mineral build up in soil that impairs plant and crop productivity. The water has minerals and after evaporation, the minerals stay.
What is the ogalla aquifer? How much has been reduced since the 1950s due to irrigation? How much does it drop per year?
One of the largest aquifers in the world
Farmers across the US take from it’s storage to irrigate their crops
9% reduction
1m per year
What has happened to the Aral Sea?
It dried up due to heavy demands on rivers feeding the Sea
Kazakhstan has decided to act and build the Kokoral dam in 2005 which helped reintroduce 15 species of fish
**What is the goal of water management? What are challenges?
To sustain the supply of high quality water for today and the future
Challenges include:
-Population increase
-Linear flow
-Multiple stakeholders
**What are water management strategies?
Build damns, aqueducts, and channels to alter the natural flow
Use sea water
Recycle through toilet-to-tap and groundwater storage
California Dry Documentary
What is the issue?
What are the effects of reduced water flow?
Water shortages in downstream communities
The delta smelt (fish) are at risk
Drought and climate change
California Dry Documentary
What are strategies being implemented?
- Desalination: Using seawater as a source of freshwater
-Requires the removal of salts which takes a lot of energy, filtration, and pressure
-Bad environmental consequences since the salt wastes go back into the ocean - Toilet to tap: Treatment of sewage water which gets pumped into the ground to replenish groundwater storage
Canada has ____% of the global supply of freshwater
7
Canada’s rate of water withdrawals have increased by ____% between 1972 and 1996
90%
Global Residential Consumption (%)
Showers and baths
Toilet flushing
Laundry
Kitchen and drinking
Cleaning
35%
30%
20%
10%
5%
**What are the 3 R’s of water conservation?
- Reduce consumption
- Repair leaking pipes, etc
- Retrofit with new efficient technologies
What are the properties of water?
- High heat capacity
- Moderates climate
- Ice floats on water
- Universal solvent
