Irrigation and Drainage Engineering · Groundwater Hydrology · 1 mark · Numerical answer
An unconfined aquifer with hydraulic conductivity 12 m/day covers 1 ha. Pumping releases 6000 m³ and lowers its water table from 3 m to 7 m below ground. Find specific yield in integer percent.
The dewatered bulk volume is $A\Delta h=10000(7-3)=40000$ m³. Specific yield is released water divided by dewatered aquifer volume: $S_y=6000/40000=.15=\mathbf{15\%}$. Hydraulic conductivity governs flow rate but is unnecessary for this storage-volume calculation.