Question

**Q2.**A 30 cm diameter well completely penetrates
completely penetrates a confined aquifer of permeability 45 m/day.
The depth of the aquifer which is equal to the length of the
strainer is 20 m. Under steady state of pumping, the drawdown at
the well was found to be 3.00 m and the radius of influence was 300
m.

- Draw the aquifer with all the available information given
- Calculate the discharge in m
^{3}/s

Note: R is the radius of influence, r_{w} is the well
radius, s_{w} is the drawdown,
*Q=**2πT**s**w*ln*(**R**r**w**)*

Answer #1

**b)Discharge in confined aquifer is given as**

where T = transmissibility of aquifer = kb

k = permeability of aquifer = 45 m/day

b = depth of aquifer = 20 m

T = 45x20= 900 m2/d

R = radius of influence = 300 m

rw = radius of well = 30/2 = 15 cm = 0.15 m

sw = drawdown in well = 3 m

Therefore putting values

= 2231.92 m3/day

= 2231.92/(24x3600) m3/s

**= 0.02583 m3/s**

A 25 cm well fully penetrates a confined aquifer of 35 m
thickness and has a permeability of 13.5 m/day When a steady state
discharge of 2400 L/min was being pumped for a long time,
observation well at radial distances of 140 m indicated drawdown of
2.2 m, Find: 1) The transmissivity of the aquifer, 2) The drawdown
at the pumping well, 3) The radius of influence, 4) The drawdown at
30 m from the well

A 30 cm well penetrates 45 m below the static water table. After
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wells 20 m and 45 m from the pumped well is found to be 3.8 and 2.4
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1. A well having 34 cm diameter penetrates 26m below the static
water level. After 24 hours of pumping at 5500l/min, the water
level in a test well at 95m away is dropped by 0.7m and at a well
38m away the drawdown is 1.2m. Determine A. Transmissibility of the
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the center of the main well to the point in the aquifer where the
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A 20 inch diameter well fully penetrates a 100 ft deep
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at 9 m and 18 m from the center of the well were found to be 12 m
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time (s)
Drawdown (cm)
0
0
10
0.6
100
5
1000
60
10000...

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