Irrigation and Drainage Engineering · Groundwater Hydrology · 2 marks · Numerical answer
A well fully penetrates a 30 m thick confined aquifer and pumps steadily at $.06\,\mathrm{m^3/s}$. Drawdowns are 3.6 m and 2.0 m at radii 60 m and 120 m. If hydraulic conductivity is $n\times10^{-4}$ m/s, find n, to two decimals.
Thiem’s confined-aquifer equation is $Q=2\pi Kb(s_1-s_2)/\ln(r_2/r_1)$. Hence $$K=\frac{.06\ln(120/60)}{2\pi(30)(3.6-2.0)}\approx1.3790\times10^{-4}\ \mathrm{m/s}.$$ Therefore **n=1.38**. The radius ratio and drawdown difference refer to the two observation wells, so the pumping-well radius is unnecessary.
More Groundwater Hydrology questions
GATE 2025 AG Q16– Which method is used for geophysical exploration of groundwater?
GATE 2025 AG Q31– An unconfined aquifer with hydraulic conductivity 12 m/day covers 1 ha. Pumping releases…