Please help me with these questions, just need the solution and explanation. I'll calculate the answers on my own
1)a) An outcrop of an unconfined aquifer has a specific yield of 22%. What is the volume of water represented by a water table decline of 140 cm over an outcrop area of 25km x 20 km during a prolonged drought ?
b) Estimate what mean annual rainfall would be required over this area to fully replenish this aquifer
2) A constant-head permeameter has a cross-section area of 250cm². The sand sample being tested is 500mm long. With a head difference of 4cm maintained, the permeameter discharges 175ml in 2.20 minutes. What is the hydraulic conductivity of the sand, in m/d ?
3) A confined aquifer is 5m thick. The piezometric surface drops 50 cm between two boreholes 0.25km apart. The aquifer’s hydraulic conductivity, K, is 10 -5 m/s. What is the volumetric flow-rate of water (in cubic metres per day) through a strip of the aquifer 1.5km wide and perpendicular to a line drawn connecting the two boreholes?
4) The Chichester Chalk-block aquifer in the South Downs has an approx. outcrop area of some 300 km2, a mean hydraulic thickness of 60m, and an average annual rainfall of 850mm. Using these given facts, and other simple hydrological knowledge gained from studying this unit, and using relevant parameter-values that you can find out for this local chalk aquifer, Estimate the following :
a) The annual groundwater recharge into this chalk block
b) The maximum groundwater level rise that this could induce in a local well.
c) The total volume of water that could, theoretically, be stored within this aquifer block