Presentation by Pierre Christe (EPA Valais) at the iMOD International User Day, during Delft Software Days 2016. Tuesday 1 November 2016, Delft.

1. Groundwater Model Visp:
An iMOD application in an alpine setting
Dr Pierre Christe
Environmental Protection Agency (SPE)
Head Groundwater Group
Delft Software Days
Tuesday, 1st November 2016
Département des transports, de l'équipement et de l'environnement
Departement für Verkehr, Bau und Umwelt

2. Oversight by FOEV
Protection of
Surface and
Groundwater
(quantitative +
qualitative)
Facilitate access
to quality
geological and
hydrogeological
information / data
Collaboration with
• FOEN
• swisstopo
2

3. Walliser Bote, February 2013
3
Walliser Bote, June 2013
„GW-Model Visp“: It all started with a little political and ideological controversy….
Climate change

4. 4
Switzerland, Valais and the „hotspot“ Visp
weinwanderungen.ch
Earthquake model 2015

5. 5
mammut.ch
Groundwater recharge in the Rhone valley influenced by groundwater circulations at
different depths through highly heterogeneous (hard) rock masses
Rhone-Valley
Southern Alps
Northern Alps
Visp is surrounded by steep mountains
Ground elevation model: swissAlti3D

6. 6
Visp belongs to the geothermal system Oberwallis
Geothermal systems locally influence groundwater temperatures in the Rhone Valley (thermal anomalies)

7. 7
Geographical extent and structure of the Rhone Valley aquifer
Lower Valais
Central Valais
Upper Valais
Low permeable deposits
High permeable deposits
~400 m
Max.100 m
Average 40 m
 Glacial + torrential + slope deposits
 Rhone alluvium (unconsolidated, water-bearing) vs. Flood
deposits (consolidated, low permeability)
 Multi-layered aquifer system
1
2
3

8. B B’
A
A’
Visp hydrogeological setting
8
Data: 1994-2003
Data: 2004 - 2013

9. Mountain water inflow
Juli
Rhone
JanuarFebruar
Direct GW-recharge
Juli
Vispa
JuniJuli
GW-Recording
Juli
Evaluating groundwater recharge in the Rhone-Valley: summer and winter peaks
Geotechnisches Institut, 2016
9
Supra-regional considerations  REGIONAL MODELLING!
Climatic vs. Hydrogeological processes  Snow Water Equivalent (SWE)
Area of
interest Mountain water inflow

10. + 1.8 m
+ 2.5 m
+ 5 m
Particular geometrical relationships
Stronger apparent differences in GW-amplitudes in Vispertal doesn‘t necessarily mean that the
cause of the observed phenomenon has its origin there.
Visp hydrological years 2012-2013: What has been exactly observed?
Geotechnisches Institut, 2016
Differences (2013) – (2012)
10
Aquifer
sections

11. Inflow profiles in Visp: where does the groundwater come from?
Total budget:
400 l/s = 24’000 l/min
(35’000 m3/day)
Outflow in %
Geotechnisches Institut, 2016
Inflow in %
11
~ 15’000 m3/day
(10’500 l/min)

12. Data: SPE
12
Realized and projected major underground infrastructures and construction in the area of
interest
 Confronting cumulative impacts of :
1. Permanent ground foundations
2. Temporary groundwater retentions
Visp: questionning land use practice and planning, ensure proper coordination

13. Water bearing layers
North
South
North South
Low permeable layers
Lonza
extraction
Underground
infrastructures
Direction of groundwater flow
Hard-rock
13
Deltares, 2015
Visp: using iMOD to simulate different scenarios
Parameter Min. Average Max. Parameter Min. Average Max.
KF 382.0 432.0 487.0 SF 0.181 0.300 1.122
KV 25.0 45.0 60.0 BF 0.073 1.300 15.321
LF 0.18 0.2 0.22 P 0.040 0.050 0.070
SS 4.32E-6
6.2E-5
6.23E-4
Computed parameter confidence intervals (96%).
LF Leakage Factor [d]
P Porosity [-]
SS Specific Storage [-]
KV Permeability Vispertal [m/d]
KF Permeability Rhone Valley [m/d]
SF Sideflow [-]
BF Bottom flow [mm/d]
Small uncertainty
Larger uncertainty
Large variability

14. Results: causes of the strong GW-level rise in the years 2012 /2013 in Visp
First approach with the methodological
concept.
Expected model-improvements:
• Introduction of the respective GW-
contributions from distinct geological and
hydrogeological units;
• Introduction of a weighting factor for
snowmelt rates to differentiate between
winter and spring times;
• Introduction of better rain and snowmelt
models both at the local and regional
levels;
• Model-construction of channels and
agricultural drainage;
• Inventory of all existing constructions
reaching or below GW-level;
• Better knowledge of the underground
and groundwater structure below <50m .
Lonza
Rhone
Vispa
«Mountain
processes»
«Valley
inflow»
«Wet year»
2012
14

15. What can regional groundwater models help us solve….
15

16. Area of
interest
Current iMOD model (1. Feb. 2011 to 31. Dec. 2012)
16
Transient 3D-model for GW-fluctuation

17. Area of
interest New area of
interest
Extended iMOD model (summer 2015 to summer 2016)
17

18. Conflict prevention and management
18
No, I hate
YOU!!
I hate you!
How can we actually still love
them?!

19. Excavation below piezometric level
Public safety: construction sites
Modification of hydrological relationships
19

20. Combined effects from industrial and agricultural activities on groundwater over decades!
20
Public safety: site remediation
Grossgrund-channel
Industrial site Lonza
Waste disposal Gamsenried

21. mysafetysigns.com
21
Public health: drinking water ressource

22. High damage susceptibility
Site effects, non-linear phenomena in liquefiable soils, related pore pressure effects
Burjanek et al. (2012)
22
Public security: example of the 1855 Visp M6.2 earthquake
Ground velocity
NS component
COupled
seismogenic
GEohazards in
Alpine Regions
(COGEAR)

23. Drawing Hands, M.C. Escher, 1948
23
Responsible decision, responsible actions
Prediction
Model
Uncertainties
Effective measures

24. Many thanks to…..
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25. See you soon in Visp?
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