GATE CE 2022: Environmental Engineering Quiz #2

The ground water is pumped through an aquifer having an area of 1.80 sq km which has a porosity of 0.65.Specific retention of the medium is 0.15. Find the change in the ground water storage (in Mm³) when the water table drops from 10 m to 35 m.

A fully penetrating artesian well is discharging at a rate of 25 l/sec. storage coefficient and transmissibility of aquifer us 4.5 × 10^–4 & 0.15 m²/min. Find drawdown at distance 5 m after two hour

During a recuperative test, the water is pumped out 2.8 m initially and allowed to recuperate. It was observed that the water level rises by 1.45m in 80 minutes. If the diameter of the well is 3.45m, determine by what amount the diameter need to be increased to get a yield of 5 litre per sec under a depression head of 1.65m.

A tube-well of 20 cm diameter fully penetrates a horizontal, homogeneous and isotropic confined aquifer of infinite horizontal extent. The aquifer is of 30 m uniform thickness. A steady pumping at the rate of 40 litres/s from the well for a long time results in a steady drawdown of 4 m at the well face. The subsurface flow to the well due to pumping is steady, horizontal and Darcian and the radius of influence of the well is 245 m. The hydraulic conductivity of the aquifer (in m/day, round off to integer) is_____.