where

ous elapsed pumping times during the test period, and

drawdown in feet per cycle of (log) time-

As=

plot S versus (log) t'.

drawdown curve

to = time at zero drawdown in days

An example of the use of this method of analysis in de-

an ultimate value for S'.

termining values of T, S, and k is given in figure C-6,

the extrapolated S', the originally computed T', and

using the nonequilibrium portion of the time-draw-

the original value of r2/t'.

down curve.

equilibrium pumping tests are derived for artesian

a W(u) corresponding to the computed value of u.

flow; they may be applied to gravity flow if the draw-

(5) *Recharge: *Time-drawdown curves of a test

down is small with respect to the saturated thickness

well are significantly affected by recharge or depletion

of the aquifer and is equal to the specific yield of the

of the aquifer, as shown in figure C-11. Where re-

dewatered portion of the aquifer plus the yield caused

charge does not occur, and all water is pumped from

by compression of the saturated portion of the aquifer

storage, the H' versus (log) t curve would resemble

as a result of lowering the groundwater. The procedure

curve a. Where the zone of influence intercepts a

for computing T' and *S *for *nonequilibrium gravity*

source of seepage, the H' versus (log) t curve would re-

semble curve b. There may be geological and recharge

conditions where there is some recharge but not

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