M. Sauter(1), S. Schmidt(1), M. Abusaada(2), T. Reimann(3), R. Liedl(3) and T. Geyer(1)
(1) Geowissenschaftliches Zentrum, Georg‐August‐Universität Göttingen, Göttingen, Germany
(2) Palestinian Hydrology Group, Ramallah, West Bank
(3) Institut für Grundwasserwirtschaft, TU Dresden, Dresden, Germany
International Conference on Integrated Water Resources Management
Dresden, 12.10.2011
Water resources management in karst aquifers – a concept for the Lower Jordan Valley?
DEM and outcrops of carbonates in the Lower Jordan Valley
Green colour: carbonates
DEM and outcrops of carbonates in the Lower Jordan Valley
Green colour: carbonates
Groundwater
from
carbonate aquifers
is
the
main
water
resource
in the
region.
Conceptual
model
of karst
systems
Double porosity
behaviour‐
Conduit
system
vs
fissured
matrix
High permeability
of karst
systems‐
Lack of surface
water‐
Exploration of groundwater from
low‐elevation springs in valleys
Problems‐
Difficult
to study‐
Surface
and subsurface
catchments
do not
conincide‐
Low probability
of wells
intersecting
the
channel
network
Double porosity
behaviour‐
Present
of conduit
system
High permeability
of karst
systems‐
Lack of surface
water‐
Exploration of groundwater from
low‐elevation springs in valleys
Problems‐
Difficult
to study‐
Surface
and subsurface
catchments
do not
conincide‐
Low probability
of wells
intersecting
the
channel
network
In the area of the Jordan Valleysome cities and villages depend to
a much greater extent on spring water than on pumped water
(Jericho, Auja, Wadi Sir).
Conceptual model of karst systems
Example: Auja spring
Mean discharge Auja
(1967 ‐
2000) 9 Mio. m³/a
Rusteberg et al.
Example: Spring discharge Auja and Sultan / West Bank
Auja: maximum discharge shortly after rainiest month and
sometimes drys up towards the end of the winter season.
Sultan: Stable discharge without high response to precipitation
changes recharge area far away from the
spring and larger storage volume
Example: Spring discharge Auja and Sultan / West Bank
Deficit and Potential for Regulation (Kresic and Stevanovic 2010)
‐
Secure additional quantities of water during periods of increased demands
‐
Sufficient aquifer replenishment during wet seasons, otherwise water table
decline is guaranteed
‐
Implies engineering interventions to control spring flow and managing spring
water contribution
Management concepts
Active management
‐ Underground / Spring dams
Increasing water level may yield to an increase
of the hydraulic head in the aquifer retention effect
‐(Over)pumping
‐Managed aquifer recharge
Passive management
The optimal use of the discharging groundwater under natural discharge
conditions.
Active and passive management require modeling approaches to predict impact
on spring discharge, water levels and water quality
Shallow karst vs. Deep karst
Dynamic phreatic storage
Static phreatic storage
Dynamic vadose storage
Dynamic surfaceStorage (snow pack)
Deep karst Shallow karst
Aquifer basePhreatic zone
Vadose zone
b)
a)Dynamic phreatic storage
Static phreatic storage
Dynamic vadose storage
Dynamic surfaceStorage (snow pack)
Deep karst Shallow karst
Aquifer basePhreatic zone
Vadose zone
b)
a)
Shallow karst vs. Deep karst
Dynamic phreatic storage
Static phreatic storage
Dynamic vadose storage
Dynamic surfaceStorage (snow pack)
Deep karst Shallow karst
Aquifer basePhreatic zone
Vadose zone
b)
a)Dynamic phreatic storage
Static phreatic storage
Dynamic vadose storage
Dynamic surfaceStorage (snow pack)
Deep karst Shallow karst
Aquifer basePhreatic zone
Vadose zone
b)
a)
Shallow karst (Seichter Karst, Jura Type)• no significant storage below elevation of spring
discharge• no opportunities for additional groundwater extraction beyond natural outflow
• tends to dry up due to gravity drainage at the sloping base
Shallow karst vs. Deep karst
Dynamic phreatic storage
Static phreatic storage
Dynamic vadose storage
Dynamic surfaceStorage (snow pack)
Deep karst Shallow karst
Aquifer basePhreatic zone
Vadose zone
b)
a)Dynamic phreatic storage
Static phreatic storage
Dynamic vadose storage
Dynamic surfaceStorage (snow pack)
Deep karst Shallow karst
Aquifer basePhreatic zone
Vadose zone
b)
a)
Deep karst
(Tiefer Karst,
Vauclusion Type)• discharge at a lateral boundary
(e.g. river valley)• displays considerable storage
volume below the discharge level
Overpumping of the Lez system (Avias 1995, Fleury et al. 2009)
Overpumping of the Lez system
Data: BRGM Montpellier
Discrete modeling approach ‐
CAVE model (Liedl et al. 2003, Birk et al. 2005, Reimann et al. 2011)
Karst aquifer CAVE
Fissured matrix
Conduit system Discrete pipe network
pipes
nodes
MODFLOW
Concept Numericalmodel
CAVE
Carbonate Aquifer Void Evolution
Link between hydraulic, transport and genesis
( )cfex hhQ −= γ
⎟⎟⎠
⎞⎜⎜⎝
⎛+−=
fae
f Re51.2
71.3log21
*1.10 avD =
Flow in the pipes
Transport in the pipe network
Transfer
Lhagv cΔ
=2*
2
2v
gaLf
hc =Δ
Darcy‐Weisbach Colebrook‐White
h_c, h_f head, L distance, f friction factor, e roughness height, a conduit diameter, g gravitational acceleration, v. friction velocity, D dispersion coefficient
Forward modelling of large scale pumping tests in synthetic karst aquifers with different conduit networks
Catchment area: 7 x 8 km2; Conduit volume: 150 000 m3; Pumping rate: 1 m3s‐1
Hydraulic heads in the fissured matrix during pumping
Pumpingwell
Discrete modeling approach ‐
CAVE model (Reimann et al. 2008)
First steps
Set‐up of a geological model for the area of investigation and aquifer characterisation
Upper aquifer
Aquiclud
e
Aquitard
Lower aquifer
Torsten Lange, Sebastian Schmidt
Conclusions
•
Model techniques are available
Technical requirements for active management
FIRST ‐
Requires comprehensive research to get knowledge of aquifer geometry and characteristics:
1.
Storage properties and the aquifer transmissivity
2.
Degree of karstification and position of karstification base
3.
Deep or shallow aquifer systems
Socio‐economic‐environmental requirements for active management
‐
Environmentally sound
‐
Economically feasible (e.g. energy costs for pumping)
‐
Political willingness
Sultan spring
Acknowledgements
•
PWA, MEKOROT, Al Quds University
•
BRGM Montpellier
•
Town Montpellier and Conseil Général de l‘Hérault
•
VEOLIA Eau à
Montpellier
•
BMBF (Federal Ministry of Education and Research)
•
DFG (German Research Foundation)
Planning and evaluation of karst management activities ‐
Modelling approaches to simulate flow in karst aquifers ‐
(Teutsch and Sauter 1991, Sauter et al. 2006)
Classification of distributive parameter models (SCPE, "Single Continuum Porous Equivalent", DCPE "Double Continuum
Porous Equivalent“, HM, "Hybrid Model", DSFS "Discrete Single Fracture Set", DMFS "Discrete Multiple Fracture Set“)
(from Teutsch & Sauter 1991).
Karst settings, karst management and model applications
Management type Problem type Setting Model type
Active Management Hydraulic Basin control Continuum models
Hydraulic Conduit control Hybrid models
Structural Subsurface dams Hybrid models
Passive Management Hydraulic Surface storage Hydrological models
Hydraulic Vadose storage Transfer functions
Hydraulic Phreatic storage Continuum models
Dam construction
Increasing water level may yield to an increase of the hydraulic
head in the aquifer
retention effect
Advantages of underground dams
–
Mimimal loss of water by evaporation
–
Water qualitiy – no salinisation, no eutrophication, less sedimentation than in surface dams
–
No problems with compensation or relocate people
Disadvantages of underground dams
–
Possible leakage
–
Not predictable storage amount
–
High costs and uncertain results
Requirements
–
Identification of the existence of preferential flow pathways (Sebasatian: Jericho ‐
Dujuk)
–
Bottom of the spring is in contact with the impermeable aquidard
and srrounded by
impermeable material laterally
(Kresic and Stevanovic 2010)
Examples (Kresic and Stevanovic 2010)
Overpumping of the Lez catchment area (Fleury et al. 2009)
•
Deep aquifer system close to the Mediterranean Sea
•
Install pumps in submerged channels below spring elevation
•
Overpump the system in periods of high water demand during summer
Duyuk spring
• EC
• Temperature
• Water level
Sultan spring
• EC
• Temperature
• Water level
• pH
• Turbidity
First steps
Spring monitoring for aquifer characterisation
1
Conceptual model carbonate aquifers
2
Example: Auja catchment (Lower Jordan Valley)
3
Spring regulation
4
Classification of karst environments
5
Overview: Management strategies
6
Examples from other regions
Investigated system: part of the conduit system
Scale: catchment scale
Disadvantage: characterisation of a small part of a karst aquifer
Investigated system: fissured matrix blocks
Scale: local scale
Disadvantage: small scale tests
Artificial tests
Global approaches with natural source
Investigated system: conduit system, fissured matrix blocks
Scale: catchment scale
Disadvantage: unknown input signal
Characterisation techniques (Geyer 2008)
Discrete modeling approaches ‐
scenario (Reimann et al. 2011, WRR)
( ) 00
2=−+
∂∂
+⎟⎟⎠
⎞⎜⎜⎝
⎛∂∂
+∂∂ ssgA
xhgA
AQ
xtQ
fC
Geological cross‐section
http://exact‐me.org/overview/p0809.htm
Discharge generation in karst environments (Hobbs and Smart 1986)
Some
notes
Questions:
Map with well fields
and springs?
Number
of springs
in the
region
Multiparametersonde …
Karte lower
upper
aquifer
GEORG-AUGUST-UNIVERSITÄT GÖTTINGEN
The Lower Jordan Valley (LJV)
Countries: Jordan, Israel and PalestineClimatic conditions: arid to semi-arid Evaporation: 2000 to 2500 mm /aPrecipitation: 50 to 700 mm /aElevation: -400m to 1200 mMain Sources: Spring discharge and GWProblems: water scarcity, pollution, gw-over-exploitation, salinization etc. Similarity of water resources systems and challengesHigh Risk of water related conflictsSustainable development urgently requiredJoint management of WR urgently required