When natural percolation of precipitation is insufficient to replenish groundwater withdrawn for human use, artificial recharge helps prevent aquifer depletion, subsidence and saltwater intrusion. Spreading grounds are one of several available technologies, and are useful to harness storm water runoff in populated areas with low annual precipitation.
A recharge basin 50 m wide and 100 m long is used to recharge an unconfined aquifer in which the natural water table is 10 m above the impervious boundary. Determine the rise in the mound below the center of the basin after 15 days from the instant the infiltrated water reached the water table. The infiltration rate is 17 cm /per day, and the transmissivity and specific yield are, respectively, 0.034 m2 per minute and 0.12.
If the infiltration stopped after 15 days, determine the decay in the groundwater mound 6 days later below the center of the basin.
Solve the problem using MAGNET and an analytical approach. Compare the results.