Hydro-geophysical techniques for environmental ... · PDF fileHydro-geophysical techniques for environmental applications: monitoring, modeling and future ... Hydrocarbon exploration

G. Cassiani et al.
Hydro-geophysical techniques for environmental applications: monitoring, modeling and future challenges.
Giorgio Cassiani
Dipartimento di Geoscienze Universit di Padova
with (in Random Order):Markus Wehrer,, Rita Deiana, Klaus Haaken, Jacopo Boaga, Claudio Paniconi, Giulio Vignoli, Matteo Rossi, Maria Teresa Perri, Damiano Pasetto, Mario Putti, Marco Marani, Alberto Bellin, Bruno Majone, Nicoletta Fusi, Sebastiano Piccolroaz, Franco Palmieri, Andy Binley, Andreas Kemna, Enzo Rizzo, Giuseppe Fadda, Simona Consoli, Daniela Vanella, Adrian Flores Orozco, Gabriele Manoli, Peter Dietrich, Ulrike Werban, Gian Piero Deidda, Nadia Ursino, Andrea DAlpaos, Matteo Camporese, Oscar Cainelli, Alberto Villa, Paolo Frattini, Giovanni Crosta, Bruno Della Vedova, Paolo Salandin, Isabella Gervasio, Enrico Dezzan, and others that I may have forgotten.

G. Cassiani et al.
Geophysical Imaging

G. Cassiani et al.
What is the role of applied geophysics ?
SITE CONCEPTUALMODEL
SITE CHARACTERIZATION
DESIGN OF SITE CHARACTERIZATION

G. Cassiani et al.
Geophysical measurements
instrument
domain of investigation
G = measured (geo)physical quantity
P= (geo)physical parameter spatially distributed in the subsoil, influencing response G
G = G(P, F = forcing conditions)

G. Cassiani et al.
PROCESSINGINVERSION
distributionof P(x,y,z)
(estimated)ANALYSIS
informationfor end users(site conceptual model)
Physicsphysical
parameter P(x,y,z)
signal G(x,y)
MEASUREMENT

G. Cassiani et al.
GEOPHYSICALMETHODS APPLICATIONS
Geo-electrics Seismics GPR EM methods Gravimetry Magnetism ...
Hydrocarbon exploration Mineral exploration Engineering studies Hydrogeological studies Contaminant identification Geological investigations Forensic studies Archaelogical studies ...
?

G. Cassiani et al.
The choice should be made according to the following criteria:
the goal of the application must be compatible with the measured physical quantity
the method must have sufficient spatial (and temporal) resolution and sufficient penetration
cost
logistics
environmental impact
GEOPHYSICALMETHODS APPLICATIONS

G. Cassiani et al.
SUMMARY
Hydro-geophysics: a problem-driven discipline
A Glimpse to a number of applications
Conclusions and outlook

G. Cassiani et al.
HydrologyFloodsMountain slope stabilitySoil/groundwater contamination
Environmental fluid-dynamics (hydrology)
Shallow geophysics (hydro-geophysics)
Water in the shallow subsurfacecarries energymodifies the state of stresscarries contaminants

G. Cassiani et al.
Applicable methods and measured physical quantities
Self Potential
Gravimetry
MagneticsGround Penetrating Radar
Gamma ray spectrometry
DC resistivity methodsElectro-magnetic methods
METHODSeismics
(Spectral) Induced Polarization
Nuclear Magnetic Resonance free water content and decay time
elastic properties and density
density
dielectric constant (electrical conductivity)
natural gamma radiation
electrical conductivity /resistivity
electrical conductivity /resistivity
magnetic susceptibility / permanent magnetization
complex electrical conductivity
DC sources
PHYSICAL PROPERTY

G. Cassiani et al.
What geophysical methods can help define

G. Cassiani et al.
water table
aquifer confining layer
impermeablebedrock
small scalelarge scale
structure / texture

G. Cassiani et al.
water table
springevapo-transpiration
water table
impermeablebedrock
structure / texture
fluid-dynamics: e.g. time-lapse evolution of moisture content

G. Cassiani et al.
water table
springevapo-transpiration
water table
impermeablebedrock
structure / texture
fluid-dynamics: e.g. time-lapse evolution of moisture content
contamination

G. Cassiani et al.
Applicable methods and subsurface characteristics
Self Potential
+GravimetryMagnetics+
Ground Penetrating Radar
Gamma ray spectrometry
+DC resistivity methods+Electro-magnetic methods
CONTAMINATIONSTRUCTUREMETHODSeismics
(Spectral) Induced Polarization
+
++++++++++
Nuclear Magnetic Resonance
+++
++
++
++
++++
DYNAMICS
+++
+

G. Cassiani et al.
Geophysicalmeasurements
Physicalmodel
(e.g hydrologic)
physicalparameters(e.g. hydraulicconductivity)
dynamics(fluids,
temperature)
structure(geometry,geology)
Integrate measurements and physical models that explain the space-time evolution of state variables such as moisture content, solute concentration and temperature that affect the space-time changes of geophysical response.
GOAL

G. Cassiani et al.
Vintage approach:direct link between physical properties of
models and geophysical quantities
Mazac et al., 1985
Cassiani et al., JH, 1998
Cassiani and Medina, GW, 1995

G. Cassiani et al.
Time lapse geophysics
static aspects (geology)
dynamic aspects (hydrology)
Applicable methods
Ground-Penetrating Radar (GPR)
Electrical Resistivity Tomography (ERT)
etc
Acquisition geometry(resolution-sensitivity issues)
cross-holesurface-to-hole
surface-to-surface
Hydrology Geophysicsconstitutive relationships
dielectric properties (GPR) DC resistivity (ERT)
complex resistivity (SIP)
measuredor
simulatedgeophysical
quantity(saturation,
concentration)
measured or
simulatedgeophysical
data

G. Cassiani et al.
A glimpse to applications
Hyporheic zone
Vadose zone
Hillslope
Catchment
Contamination
Critical zone
Conclusions
Aquifers
Acknowledgments

G. Cassiani et al.

G. Cassiani et al.
SUMMARY
Hydro-geophysics: a problem-driven discipline
A Glimpse to a number of applications
Vadose zone characterization
Conclusions and outlook

G. Cassiani et al.
Borehole AERT & GPR
Borehole CERT & GPR
Borehole BERT &GPR
Borehole D(cored)
trench
Characterisation of the vadose zoneof the Po river plain sediments:the Gorgonzola (Milan) test site
7.95
m
6.65 m
7.20 m
Water injection experiment in trench
22 m3 of water in 10 hours
Deiana et al., VZJ, 2008

G. Cassiani et al.
ZOPGPR
ERT
3 hr 11 hr 22 hr 45 hr 117 hr 141 hr
0 2 4 6m
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
m
0 2 4 6m
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
m
0 2 4 6m
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
m
0 2 4 6m
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
m
0 2 4 6m
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
m
0 2 4 6m
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
m
-0.01
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
Dq
0.000.020.040.06
-20.00
-16.00
-12.00
-8.00
-4.00
0.00
0.000.020.040.06
-20.00
-16.00
-12.00
-8.00
-4.00
0.00
0.000.020.040.06
-20.00
-16.00
-12.00
-8.00
-4.00
0.00
0.000.02 0.040.06
-20.00
-16.00
-12.00
-8.00
-4.00
0.00
0.000.020.040.06
dept
h (m
b.g
.l.)
-20.00
-16.00
-12.00
-8.00
-4.00
0.00
0.000.02 0.04 0.06
Dq (-)
-20.00
-16.00
-12.00
-8.00
-4.00
0.00
Dq (-) Dq (-) Dq (-) Dq (-) Dq (-)
end of injection
dept
h (m
b.g
.l.)
Gorgonzola: injection experiment

G. Cassiani et al.
Injection phase
0.00 0.02 0.04 0.06
-20
-16
-12
-8
-4
0
0.00 0.02 0.04 0.06 0.00 0.02 0.04 0.06 0.00 0.02 0.04 0.06 0.00 0.02 0.04 0.06 0.00 0.02 0.04 0.06 0.00 0.02 0.04 0.06 0.00 0.02 0.04 0.06 0.00 0.02 0.04 0.06
Dq DqDqDq DqDqDq DqDq
dept
h (m
b.g
.l.)
1 hr 2 hr 3 hr 5.5 hr 7 hr 8 hr 9 hr 10 hr 11 hr
zop GPR

G. Cassiani et al.
MASS BALANCE
MODEL FIELD DATA
known injected
mass
mass in given control volume
mass in given control volume

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Hydro-geophysical techniques for environmental ... · PDF fileHydro-geophysical techniques for environmental applications: monitoring, modeling and future ... Hydrocarbon exploration