The impact of urban groundwater upon surface water - eTheses ...

Analytical solution for the saturated thickness of the aquifer (m)
70
60
50
40
30
20
10
Sensitivity analyses of saturated thickness to different levels of seepage face (h1) and varying steepness of
gradient between the observation piezometer (h) and the river, and varying distant boundary conditions (h2).
h mean 90.86, h2 mean 93.25
h min 90.73, h2 mean 93.25
h max 91.41, h2 mean 93.25
h2 min 92.75, h mean 90.86
h2 max 93.75, h mean 90.86
2 2
2 2
h − h
⎡h h b h h ⎤
1
2 − 1 ( 2 − 1)
− b(
h − h1)
= ⎢ − ⎥x
2
⎣ 2l
l ⎦
River Level (90.3)
Datum
River
h1 h h2
x
0
90.2 90.25 90.3 90.35 90.4 90.45 90.5 90.55 90.6 90.65 90.7
River/Seepage head, h1, (maod)
b
Aquifer
Aquitard
l
90.67 is the maximum level
of the seepage face if a
linear extension of the
regional gradient is used.
Figure 6.10 Sensitivity of the analytical solution for saturated thickness to variations in boundary conditions