35.6. Specific Yield in Unconfined Aquifers

Try these first

1. 1.

   What is specific yield?

   Hint

   Think about how much water can be used compared to the total amount.

2. 2.

   Is specific yield found in confined or unconfined aquifers?

   Hint

   Remember how water is held in confined aquifers.

3. 3.

   What does specific yield measure?

   • Total volume of aquifer
   • Volume of water that drains due to gravity
   • Water retention capacity

   Hint

   Focus on how gravity influences available water.

4. 4.

   Is specific yield higher in sand compared to clay?

   • True
   • False

   Hint

   Consider the characteristics of different soil types.

5. 5.

   Consider an unconfined aquifer with a specific yield of 0.3. If the area of influence during pumping is 1000 m² and the water table declines by 5 meters, how much water is released in cubic meters?

   Hint

   Use the water release formula carefully.

6. 6.

   Analyze the impact of a new agricultural policy that encourages deep well pumping in an area noted for clay soil, known to have a typically low specific yield. How might this affect the local aquifer sustainability?

   Hint

   Think about the implications of excessive water extraction on ecosystems and water levels.