The static level of water table in an unconfined aquifer was 30 m above the underlying impermeable stratum. A 150 mm diameter well, penetrating the aquifer to its full depth, was pumped at the rate of 20 liters per second. After several weeks of pumping, the drawdown in observation wells 20 m and 50 m from the well were 3.5 m and 2 m respectively, and the observed drawdowns were increasing very slowly (B.Sc., DU, 2012). a) Assuming equilibrium conditions, estimate the hydraulic conductivity and transmissivity of the aquifer. b) Estimate the drawdown just outside the pumped well. c) What will be the yield of a 300 mm diameter well which will produce the same drawdowns just outside the well and at the 50 m distance observation well in (2)? What would be the drawdown at a nearer observation well?
The static level of water table in an unconfined aquifer was 30 m above the underlying impermeable
stratum. A 150 mm diameter well, penetrating the aquifer to its full depth, was pumped at the rate of
20 liters per second. After several weeks of pumping, the drawdown in observation wells 20 m and 50
m from the well were 3.5 m and 2 m respectively, and the observed drawdowns were increasing very
slowly (B.Sc., DU, 2012).
a) Assuming equilibrium conditions, estimate the hydraulic conductivity and transmissivity of the
aquifer.
b) Estimate the drawdown just outside the pumped well.
c) What will be the yield of a 300 mm diameter well which will produce the same drawdowns just
outside the well and at the 50 m distance observation well in (2)? What would be the drawdown at a
nearer observation well?
Trending now
This is a popular solution!
Step by step
Solved in 2 steps with 2 images
