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Hydro-structural analysis of Northern Termination
of Maiella anticline
Author: Kaisar Ahmat Supervisors: Emanuele Tondi Marco Materazzi
2014-2015
Master thesis in Structural Geology and Hydrogeology
Outline
• Introduction
• Geological setting
• Materials and data
• Modelling and simulation
• Results
• Conclusion
Introduction 1 The Maiella anticline is the outermost trust-related structure of the central Apennines is one of the most important fractured carbonate aquifer in Abruzzo
Usage M3/year %Drinking water 60.7e+6 24
Electricity generation
103.3e+6 41
Irrigation 9.5e+6 3.8Not available 78.5e+ 6 31.2
Total 252e+6 100
Previous many studies has taken place about outcropping oil show in Bolognano Fm to observe directly which structural characteristics mostly influence the fluid flow in a similar fractured carbonate reservoirIn this thesis we focus more on Groundwater and control
of hydro-structures and using modelling technique try to better understand the aquifer rock properties and subsurface fluid migration pattern .
Geological sketch of the central Apennines (Vecsei & Sanders, 1999) Red square shows the Maiella Mountain
GeologyPlateform carbonate Slop to basin Outcrop carbonate platform Retrogradation, agradationCaramanico normal fault70°-
80° deep toward west
Springs Deep, shallow aquifersTar impregnation Precipitation
Hydrogeology
Geology of northern termination of Maiella
Data and materials n˚ Spring Level(m)
m.s.l.
Disc min
Mc/s
Disc max
Mc/s
Disc av
Mc/s
1 S.Giustino 479-475 0.30 1.10 0.65
2 Acquevive 462-456 0.41 2.05 1.01
3 Verde 410 224 3.56 2.56
4 Foro 420 0.47 0.63 0.57
5 Lavino 150 0.79 3.12 1.83
6 Orfento 480-405 0 0.42 0.15
Available data for modelling are spring discharge in the area and hydraulic head from interpreted cross-sections from Nanni and Rusi ,2003
5m resolution Digital Elevation Model map of Abruzzo
Average porosity ,permeability if Bolognano marly member average porosity 0.12, average permeability 60md Calcarenite member average porosity 0.24,average permeability 330md .
Thickness of lower lias to upper TriassicDolomite di Castel Manfrino formation
800-2000m
Modelling and simulation
Conceptual model
Hydrogeological units in Nanni and Rusi 2003A.
) hydrogeological complex of Jurassic-Paleocene limestone characterized by high perme- ability due to karst and fissuring; B) an aquiclude of the Bolognano Formation consisting of marly limestone and marlstone; C) marl and marly clay;D) a hydrogeological complex of highly
permeable continental detritus.
Model boundary condition and flow system
No flow Boundaryin south
No flow Boundary West-East
(constand head )Seepage face Boundary for springs
Numerical model
• Model Development
Selected code: FEFLOWsubsurface modeling system
2D mesh generation
Software GUI
TriangularAdvancing frontgeobuilder
The mesh density of 1560nodes and 2979 elements was used in Generate Automatically option to generatethe mesh for the first slice
Model geometry and materialproperty
Thickness Average porosity
Permeability
(md)
Hydraulic conductivity
(m/s)
Gessoso-solfifera Unit
300-400 0.1 50 4.93e-7
Bolognano calcarenite unit
200 0.24 330 3.26e-6
Bolognano marly unit
150 0.12 63 6.22e-7
Hydrogeological complex
1400-2000 0.1 250 2.9e-6
Simulation and calibration
y = 0.8756x + 107.77R² = 0.939
0
200
400
600
800
1000
0 200 400 600 800 1000
He
ad S
imu
late
d (
m)
Head Observed (m)
Series1
Results
Water Budget Simulated mc/s vs mc/y Measured mc/s vs mc/y Error mc/s
Total 2.346 73.893.356 2.4 75.686.400 0.054
Lavino 1.82 57.395.520 1.83 57.710.880 0.01
Foro 0.526 16.587.936 0.57 17.975.520 0.044
Observed VS measured recharge and discharge
Simulated hydraulic headwith isolines
Model including fault For increase the goodness of the model We create another model with normal faultOf lavino spring is included and we got a better result With advantage of :More close to real hydrogeological interpretation The assigned unit parameters are in more correct range
Water Budget Simulated mc/s vs mc/y Measured mc/s vs mc/y Error mc/s
Total 2.346 73.893.356 2.4 75.686.400 0.054
Lavino 1.84 58.007.318.4 1.83 57.710.880 0.01
Foro 0.51 16.083.360 0.57 17.975.520 0.06
y = 1.0987x + 188.76R² = 0.9022
0
200
400
600
800
1000
0 200 400 600 800 1000
Sim
ula
ted
(m
)
Observed (m)
Observed VS measured spring discharge and hydraulic head
Conclusion
Creating a Groundwater Model of carbonate aquifer systems with equivalent continuous approach has been found to be suitable in simulating regional groundwater flow using regional aquifer parameters adequately reproducing the regional groundwater levels with relation to observed discharge to the springs. And to improve the model goodness, we include the fault in the termination point and get a better representation of the area.
For the future model for carbonate aquifer hydrogeological analysis, we need to obtain more data in the field. So with more sufficient data we able to create more accurate coceptual and numerical model to estimate our final goal as correct estimation of carbonate aquifer rock property variation by depth and the structural control on flow pathways
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