TM 5-818-5/AFM 88-5, Chap 6/NAVFAC P-418
(Courtesy of UOP Johnson Division)
Figure C-17. Residual drawdown versus t'/t" (time during recovery period increased toward the left).
residual drawdown at a ratio of t'/t" = 1 if there is
(C-9)
normal recovery, as well as no recharge and no discon-
where As' = residual drawdown in feet per cycle of
tinuities in the aquifer within the zone of drawdown.
(log) t'/t" versus residual drawdown curve. Displace-
The ratio t'/t" approaches one as the length of the re-
ment of the residual drawdown versus (log) ratio t'/t"
covery period is extended.
(3) The transmissibility of the aquifer can be cal-
curve, as shown in figure C-18, indicates a variance
with the assumed conditions.
culated from the equation
(Courtesy of UOP Johnson Division)
Figure C-18. Displacement of residual drawdown curve when aquifer conditions vary from theoretical conditions.
C-15
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