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Course: AP®︎/College Environmental science > Unit 4
Lesson 2: Effects of land and water use IAquifer withdrawal and recharge
Review your understanding of aquifer withdrawal and recharge in this free article aligned to AP standards.
Key points
- An aquifer is an underground layer of porous rock and sediment that contains groundwater. Aquifers are an important source of fresh water for drinking and crop irrigation.
- Groundwater recharge is the process by which water from precipitation percolates through the soil and makes its way into an aquifer, filling it up. Because groundwater tends to move slowly through soil and rock, aquifers may recharge slowly. For example, certain types of aquifers may take thousands of years to recharge.
- Aquifers offer a relatively low-cost source of water for residential and agricultural needs. However, taking water from aquifers on a large scale is unsustainable because the rate of withdrawal often outpaces the rate of recharge. Over time, this can lead to overuse and depletion.
- The Ogallala aquifer is the largest aquifer in the United States, stretching about 174,000 square miles (450,000 square kilometers). The Ogallala aquifer is the principal source of irrigation water for eight U.S. states. Intensive agricultural irrigation is draining the Ogallala aquifer faster than rainfall can recharge it. So, there is a risk that the aquifer could disappear by the end of this century.
- A large fraction of irrigation water withdrawn from the Ogallala is lost to evaporation and runoff. So, farming practices that conserve water can help protect this important resource.
Want to join the conversation?
- what happens when water is withdrawn from an aquifer
faster than it can be recharged(6 votes)- Pumping groundwater faster than it can recharge can lead to dry wells, especially during droughts.(5 votes)
- What is a farming technique that reduces runoff(3 votes)
- 'Rationing' fertilizers and making sure that there are plants surrounding bodies of water to hold the soil in place.
The key is maintaining root systems.(6 votes)
- How is the climate diffrent.(4 votes)
- What is an effective alternative to using aquifers(3 votes)
- Alternative water is water supplied by sustainable sources that can be used to help offset the use of fresh surface water and groundwater (such as lakes).(3 votes)
- What are farming practices that conserve water or prevent depletion of the aquifer? -- "aquifers offer a relatively low-cost source of water for residential and agricultural needs" -- Why are prices not increased to decrease competition for water in the aquifer?(4 votes)
- what do the colors mean(3 votes)
- The changes in level in the aquifer(1 vote)
- How much water is available in aquifers and at what rate do we consume(use up) the water in these underground reservoirs? How does this compare to the amount available in them?(2 votes)
- If water is being overused, woudn't the solution be reducing human population?(2 votes)
- Theoretically it is indeed a solution. But since reducing human population is, well, illegal? We have to resort to other solutions.(1 vote)
- Why are the central parts of the states have the most amount of water level change"?(2 votes)
- Are there different types of aquifers?(1 vote)
- Yes! These are the different types in North America (click on the link to discover this!): https://waterwelljournal.com/aquifer-types-of-north-america/(1 vote)