Water Technology and Sciences - July - August, 2014 - page 112

110
Water
Technology and Sciences
, Vol. V, No. 4, July-August, 2014
Hernández-Valdés
, Relation between Specific Capacity and Transmissivity with Non-linear Flow and Partial Penetration Well
Figure 4. Percentage values for the transmissivity correlation factor with specific capacity for the 90
samples from Table 3.
Table 4. Wells from Table 3 with at least one satellite well.
Well
T
D
(m
2
/d) Distances (m)
Wells for
T
T
T
T
(m
2
/d)
Darcy
Radial (m)
Qs
(lps/m)
T
D
/
Q
S
Factor
RNL
Observations
94
27 902 0.25 and 23.3 3 049
124
54
517
455
*Partial penetration
Fp
= 0.92
89
27 112
0.2 and 100 1 250
162
27.4
989
670
*Partial penetration
Fp
= 0.8
1160 12 482
0.25 and 15 2 538
80
40
311
335
Ok
22
11 330
0.2 and 60
1 920
72.6
31.16
363
364
Ok
966
2 900
0.3
,
38
and 60 823
79
12.2
237
295
Calculation error for
T
T
15
373
0.2,
10 and 15
120
224
1.65 0.438 226 851
883
Inadequate
Qs
valueo
*The calculated values of the partial penetration were obtained by applying Factor
RNLpp
(20).
Hernández-Valdés (2008) and the pumping
data are graphically shown.
This pumping test was conducted with
a flow volume of 26 lps in a 40 cm diameter
well and the drawdown was measured in
two satellites located 9.7 and 15 m from the
pumping well, respectively.
Calculation of Darcy’s Transmissivity T
D
The procedure described by Cooper and
Jacob (1946), cited by Todd (1959) is followed,
obtaining the slope per
D
St
10
cycle from the
graphic representation of
S vs.
log(
t
) and then
determining
T
D
using the following expression:
T
D
=
0
.
183
Q
St
10
=
0
.
183 26 86
.
4
1
.
1
=
373
m
2
/ d
Calculation of Turbulent Transmissivity T
T
Since the fitted lines in the semi-logarithmic
graphs in the previous section should be
parallel, the difference in drawdown among
1...,102,103,104,105,106,107,108,109,110,111 113,114,115,116,117,118,119,120,121,122,...200
Powered by FlippingBook