Expert: Jeanette A - 1/9/2009

Question
what would be the major impediment of using Theis Equation in reality?

with thank

Answer
Hello Ammar,

The Theis equation was derived under the assumption that total stress in the aquifer was constant and the mechanical behavior of the confining unit was neglected. In reality, most geological formations, especially those which are well consolidated, have rigidity and therefore may bend like a plate to a certain extent. The increase in the effective stress in the aquifer due to pumping may not contribute entirely to the compression of the aquifer, but may be partially cancelled out by bending of the overlying aquitard. This means only a part of the total stress is used to compact the aquifer, or the aquifer cannot produce as much water as estimated from the Theis equation.

Hope this has helped.


Warm Regards,
Jeanette