Joint use of natural and artificial tracers to determine infiltration

Joint use of natural and artificial tracers to
determine infiltration processes and the
hydrogeological functioning of a karst system
Matías Mudarra-Martínez and Bartolomé Andreo-Navarro
Centre of Hydrogeology and Department of Geology, University of
Malaga, Spain
[email protected]
Introduction
General characteristics
Methodology
Results and discussion
Conclusions
Used to determine the origin, movement
and transfer pathway of groundwater
Environmental
Artificial
From Schaer et al., 1998
Not commonly are used jointly to investigate the
hydrogeological functioning of karst aquifers
Goals
Understanding the
hydrogeological functioning
(infiltration processes, recharge
mechanisms and types of
flowpaths) of the Villanueva del
Rosario system (Málaga
province, southern Spain).
DYE TRACERS
FLUORESCENTS TRACERS (Benischke et al., 2007)
INJECTING DYE TRACERS
NATURAL TRACERS
Hunkeler y Mudry (2007)
NATURAL FLUORESCENCE AS TRACER OF INFILTRATION IN KARST
Excitation-emission matrix (EEM):
Excitation (λ
λex) from wavelength of 200 nm to
350 nm, with a 5 nm slit.
Emission (λ
λem) ranged from wavelengths of 250
to 550 nm.
A. Baker, D. Genty / Journal of Hydrology (1999)
NATURAL FLUORESCENCE AS TRACER OF INFILTRATION IN KARST
Mudarra, Andreo
and Baker(2011)
SOME EQUIPMENTS FOR TRACERS ANALYSIS
Espectrofluoremeter
Total Organic Carbon Analyser
Portable Espectrofluoremeter
Ionic Chromatography
Introduction
General characteristics
Methodology
Results and discussion
Conclusions
Villanueva del
Rosario system
14 km2.
Sierra Camarolos
and Sierra del
Jobo aquifer (28
km2).
Altitudes ranging
from 600 to
1,640 m a.s.l.
Mean historic
annual
precipitation and
temperature are
670 mm and 14
ºC (temperate
Mediterranean).
Introduction
General characteristics
Methodology
Results and discussion
Conclusions
Geology
Jurassic dolostones and limestones with a maximum total thickness of 400 – 450 m.
Bottom: Upper Triassic clays with evaporite rocks. Top: Cretaceous-Paleogene marly-limestones.
ENE-WSW lying folds, from which overthrusts have developed with vergence toward S-SE.
Around the aquifer and overthrusting it are outcrops of Flysch-type clays and sandstones.
Introduction
General characteristics
Exokarstic
features
Methodology
Results and discussion
Paisaje general del área de Los Tajos desde el borde sur
Well developed
at higher
altitudes.
Epikarst:
karrenfields,
dolines and
uvalas.
No soil cover,
only locally (in
karst
depressions) is it
possible to find
an edaphic layer
(10-15 cm max.).
Few potential
sources of water
contamination.
Conclusions
IP-2, located at
1,315 MASL
IP-1, located at 1,148 MASL
Karst swallow holes active during heavy rainfall.
Introduction
General characteristics
Methodology
Results and discussion
Conclusions
Rainfall station located at 1,130 MASL
Gauging station installed about 800
m downstream
Lab spectrofluorometer
From 1st February to 17th February 2009:
hourly records of discharge, mineralization, temperature of the
water and rainfall.
52 water samples from the spring, at progressively increasing
intervals from two hours to two days .
Introduction
General characteristics
Methodology
Uranine (Acid Yellow 73, CAS: 518-47- 8)
IP-1
Injection points
UTM X (Zone 30N)
UTM Y (Zone 30N)
Altitude (MASL)
Tracers (mass)
Date and hour of injection
Discharge (l/s)
E.C. (µS/cm)
Temperature (ºC)
Recovery rate (%)
Results and discussion
Conclusions
Eosin (Acid Red 87, CAS: 17372-87-1)
IP-2
IP-1
385245
4095626
1,148
uranine (3 kg)
02/05/2009 15:30
10
97
3.2
71
IP-2
382328
4092703
1,315
eosin (2 kg)
02/05/2009 16:00
25
210
2.7
21
Cl- and NO3-: Metrohm ion
chromatography (791 Basic IC
model).
TOC content Shimadzu V-TOC
carbon analyzer .
Intrinsic fluorescence (peaks A and
C) and artificial tracers: PerkinElmer LS55 spectrofluorometer.
DAY TRACERS DETECTED IN VILLANUEVA DEL ROSARIO SPRING
PIPI-1
PIPI-2
Hydrodynamic results
RESULTS OF THE TRACER TEST
27 hours after injection.
Maximun value: 19,10 µg/L (to
30,5 hours). Highest flow
velocity: 245 m/h (modal
velocity of 215 m/h).
17 hours after injection.
Maximun value : 3,29 µg/L (to
22,5 hours). Highest flow
velocity: 190 m/h (modal
velocity of 145 m/h).
Recovery rate: 21%
for eosine
Recovery rate: 71%
for uranine (Vva. del
Rosario + TP)
Introduction
General characteristics
Methodology
Results and discussion
Conclusions
Complementary use of natural and artificial tracers in karst
hydrogeology.
Vva. Del Rosario system has a high degree of karstification (conduit flow
systems), rapid groundwater flow and low inertia.
Hydraulic head variations (flow) are faster than those of temperature
and of chemical composition (mineralization, natural tracers) and even
faster than artificial tracers.
Global system response (given for natural fluorescence and TOC) is
faster and more sensitive than that produced concentrated infiltration.
Flow velocities can only be quantified using artificial tracers.
This integrated approach is useful for mining activities in karst areas.
CONCEPTUAL MODELS
Low waters
High waters
Mudarra , Andreo and Mudry (2012)
VI CURSO SOBRE HIDROGEOLOGÍA KÁRSTICA
6th Training-course on KARST HYDROGEOLOGY
Málaga (Spain), 16 al 20 septiembre de 2013
Facultad de Ciencias. Universidad de Málaga
www.cehiuma.uma.es
ORGANIZA
COLABORA
Unidad Asociada IGME-UMA
“Estudios Hidrogeológicos Avanzados”
Special session on Hydrogeology for mining activities in Karst
Experiences from South America on mining in karst are welcome
www.cehiuma.uma.es
[email protected]