Deficit Within The Water Cycle Flashcards
What do we mean by deficit in the water cycle?
Great outputs than inputs = Depletion of stores
What might cause deficits in the water cycle?
- Seasonal variation
- Long-term climate change
- Human depletion for use
- Wet seasons = Increased surface runoff
- Dry seasons = Reduced discharge and runoff
- Mountain regions, increased flow and runoff due to melting ice
Define water stress
Total withdrawal exceeds renewable inputs to system
Name 3 countries which experience high water stress
- Within tropics (NOT Central Africa or SE Asia due to low population)
- SE Australia (High population)
- Central and Western USA (High population)
How does climate change impact weather?
- High temps = More evaporation
- More evaporation = More intense rainstorms
- Intense rainstorms = Increase risk of flooding, runoff into rivers don’t dampen soil
- Increased temps + Dry soil = Increase risk of drought
What are the 2 stores of freshwater?
- Surface water stores e.g. Lakes
- Aquifers
What do humans extract water for?
- Household activities e.g. Washing
- Drinking water for increasing pop.
- Irrigation
- Industrial processes e.g. Steel production
- Recreation e.g. Swimming
- HEP generation
What is an aquifer?
Permeable porous water bearing rocks e.g. Chalk
What is an artesian aquifer?
Develop where sedimentary rocks form basin like structure, aquifer confined between impermeable rock layers
How are aquifers recharged naturally?
Through water cycle, over time
Name the 2 ways in which humans artificially recharge aquifers
- Groundwater recharge (Ponds/wells to put water into depleted aquifers)
- Microfiltration and percolation basins (Contaminated fluid is passed through a membrane to separate microorganisms and suspended particles)
Give an example of groundwater recharge
- Santa Clara County, California
- Use recycled water to recharge aquifers
- Additional 15 billion gallons for aquifer
Give an example of microfiltration
- Orange County, California
- Purification of waste water (Microfiltration, reverse osmosis and UV light with hydrogen peroxide)
- Pumped into recharge basin to percolate into ground
- 100 million gallons per day, water for 850,000