use of available information to infer groundwater- surface water interactions - practical examples...
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Use of Available Information to Infer Groundwater-Use of Available Information to Infer Groundwater-Surface Water InteractionsSurface Water Interactions - Practical Examples from BC- Practical Examples from BC
Jacek Scibek M.Sc.
1. BC observation well network – examples of water levels and interactions with
surface water
2. Delineating areas of aquifers where GUDI wells are likely to occur
3. Aquifer heterogeneity
OUTLINE:
Nanaimo River
Nanaimo River gauge
CASSIDY
Obs 312
Obs 228
Obs 330
N
Cassidy Aquifer (Nanaimo)Example 1:
Nanaimo River Obs 312
Obs 228
Obs 330
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Aug Sep Oct Nov Dec Jan
Month
Gro
undw
ater
Lev
el(m
ab
ove
low
est
wat
er le
vel r
ecor
ded)
Obs 228 water level
Obs 312 water level
Obs 330 water level
2003 2004
Obs 330
Obs 312
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Aug Sep Oct Nov Dec Jan
Month
Gro
undw
ater
Lev
el(m
ab
ove
low
est
wat
er le
vel r
ecor
ded)
Obs 312 water level
Obs 330 water level
2003 2004
Wellfield drawdown
Recovery event
Nanaimo River
Obs 312
3.0
3.2
3.4
3.6
3.8
4.0
4.2
4.4
Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Aug Sep Oct Nov Dec Jan
Month
Gro
undw
ater
Lev
el(m
ab
ove
low
est
wat
er le
vel r
ecor
ded)
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Nan
aim
o R
iver
Wat
er L
evel
(m
eter
s,
conv
erte
d fr
om f
low
dat
a)
Obs 312 water level
Nanaimo River water level(computed from discharge)
2003 2004
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
Oct Nov Dec Jan Feb Mar Apr
Wa
ter
Le
ve
l (m
a
bo
ve
loc
al d
atu
m)
Obs 228 water levelObs 312 water levelObs 330 water levelNanaimo River water level
2003 2004
Nanaimo River
Obs 312
Obs 228
Obs 330
Wells near rivers are potentially GUDI
Cowichan River Valley (Duncan)Example 2:
318
204
River Gauge
211
205
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Oct-95 May-96 Dec-96 Jun-97 Jan-98 Jul-98 Feb-99 Aug-99 Mar-00 Oct-00 Apr-01
Wa
ter
Le
ve
l (m
ab
ov
e lo
ca
l da
tum
)
0
100
200
300
400
500
600
Riv
er
Flo
w (
m3
/s)
#205
#318 FISH HATCHERY#211
#208Cowichan River 08HA011
Note flow magnitude in river!!
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Feb-05 Feb-05 Mar-05 Mar-05 Mar-05 Apr-05 Apr-05 Apr-05 May-05 May-05 May-05
Wa
ter
Le
ve
l (m
ab
ov
e lo
ca
l da
tum
)
0
20
40
60
80
100
120
140
Riv
er
Flo
w (
m3
/s)
#318 FISH HATCHERY
#211
Cowichan River 08HA011
Rough sketch of area of interaction of groundwater with surface water
Grand Forks ValleyExample 3:
Obs well
Kettle River
504.0
504.5
505.0
505.5
506.0
506.5
507.0
1982 1983 1984 1985 1986 1987 1988 1989 1990 1991
Date
Riv
er W
ater
Ele
vatio
n (m
a.s
.l.)
509.0
509.5
510.0
510.5
511.0
511.5
512.0
512.5
Gro
undw
ater
Ele
vatio
n (m
asl
)
Kettle River (channel elev 509.6 m) near Obs Well 217
Obs Well 217 (elev 513.5 m)
River recharging aquifer
Aquifer discharging to river
Effect of aquifer heterogeneity on connection with surface water:
head difference map = Aquifer Scenario 1 – Aquifer Scenario 2
(homogeneous K) (heterogeneous K)
- 0.5 m
+ 0.5 m
0 m
Fraser Valley (Abbotsford)Example 4:
No GUDI wells up-gradient from rivers? How far?
Stream leakage?
Complex flow patterns (modeling results)
CONCLUSIONS:
1. Available information:
- often not used- significance missed- objective is to avoid expensive tests done that
confirm what is already known
2. BC observation well network
- free source of data- most wells too close to rivers to help characterize
aquifer behaviour