The Radius of Influence, R(t), is the horizontal radial distance from a well to the points in an aquifer where there is negligible influence from pumping. The influence radius of a pumping well depends on two key factors - hydraulic diffusivity (T/S) and time.
Problem A. Use 1) dimensional analysis and 2) the Theis solution to show that R(t) is proportional to sqrt (T/St)
Problem B. Explain both mathematically and physically why the impact of pumping on a confined aquifer is dramatically larger than that on a unconfined aquifer,
Problem C. Develop a MAGNET model that can reproduce the Theis solution for the following specific situation and perform a sensitivity analysis of the aquifer drawdown model with respect to hydraulic conductivity, storage coefficient, and time.
Given information:
- K = 100m/day,
- Aquifer thickness = 20m
- Storage coefficient = 0.0001
- specific yield = 0.1
- pumping rate = 1000 m3/day
MAGNET/Modeling Hints: