Study of Water Reservoirs at Different Hydrological and Climatic

Study of Water Reservoirs at Different Hydrological and Climatic

Study of Water Reservoirs at Different Hydrological and Climatic Systems in
Spain Based on a Map of Isotopic Distribution in Precipitation
1Bardasano
L, 1Rodríguez-Arévalo J, 2Villarroya F.
1Centro
de Estudios y Experimentación de Obras Públicas (CEDEX). Madrid (Spain). [email protected]
2Facultad de Ciencias Geológicas. Universidad Complutense de Madrid (Spain).
OBJECTIVES
ISOTOPIC STUDY OF WATER RESERVOIRS
RESULTS
This paper presents a methodology that puts into practice the model of the spatial
distribution of δ18O in precipitation over Spain, to determine the isotopic composition of
water reservoirs and their river basins. This is meant to:
1) help identify factors that regulate the isotopic composition in water reservoirs from
different hydrological and climatic systems within the country;
2) improve on the understanding of the water budget, by defining a more precise
evaporation line at the selected sites and;
3) provide δ18O referenced values to be used on hydrological studies of lakes and water
reservoirs.
The methodology followed consisted on:
a) Selection of water reservoirs in order to have a wide representation of the geographicclimatic and physical variability present in Spain. These are: Yesa (Zaragoza), Tous
(Valencia), Ulldecona (Castellón), Gargáligas (Badajoz) and Giribaile (Jaén).
b) Characterization of the isotopic content (Deuterium and Oxygen-18) observed in the
selected water reservoirs, relative to the Local Meteoric Water Line (LMWL) of the
Peninsular Spain and Balearic Islands.
c) Comparison between the observed isotopic content of different water reservoirs with the
mean value of δ18O in precipitation over their watersheds, calculated by the use of GIS
tools.
The isotopic fingerprint reveals evaporation processes taking place in most of the water
reservoirs studied in Spain, specially that of Gargáligas.
Isotopic data from REVIP stations show δ18O values in precipitation heavier than those of the
reservoirs, except at Gargáligas. This is due to the effect of altitude differences between
REVIP stations and the areas of meteoric water source in the studied sites.
A new evaporation line is determined when using as a reference, the mean value calculated
with the continuous map of δ18O in precipitation, over each of the watersheds studied. This
line helps to define precisely the tracing of the meteoric water source.
0
Yesa (2007-2009)
Tous (1998-2009)
Ulldecona (1998-2009)
Gargáligas (2008-2009)
Giribaile (2000-2009)
LMWL
-10
-20
REVIP NETWORK/
MAP OF ISOTOPIC DISTRIBUTION IN PRECIPITATION IN SPAIN
Data collected from the Spanish Network for Isotopes in Precipitation (REVIP), during the
time period that runs between 2000-2006, has allowed for a continuous digital map of the
δ18O distribution in precipitation over the Peninsular Spain to be performed (Díaz-Teijeiro,
2009; Rodríguez-Arévalo et al., 2012). This map is based on a multiple regression model
depending on two geographic factors: latitude and elevation. Nowadays, the Centro de
Experimentación y Obras Públicas (CEDEX) investigates on the possibilities that offers a
map to provide δ18O reference values that could be used on studies of surface hydrology
and, in particular, on water reservoirs.
2
d H(‰)
YESA
ULLDECONA
-30
-40
-50
-60
TOUS
-70
-80
GARGÁLIGAS
-12
-10
-8
-6
-4
GIRIBAILE
0
-10
-40
-50
Tous (observed)
Tous (modeled)
REVIP station
LMWL
Trend line
-60
-70
-80
-12
-10
-20
-20
-30
-30
Zaragoza
-40
2
Ciudad Real
Madrid
-8
-6
-4
Ulldecona (observed)
-60
REVIP station
LMWL
-60
REVIP station
Trend line
-70
-70
-10
-8
d O (‰ )
-6
y = 5,2465x - 7,9995
R2 = 1
-20
-30
-30
-30
-40
-50
Rodríguez-Arévalo, J.; Díaz-Teijeiro, M.F.; Castaño, S., 2012 [IAEA, in press]. Modelling and
mapping oxygen-18 isotope composition of precipitation in Spain for hydrologic and climatic
applications.
GMWL
Valladolid
-60
LMWL
León
Mediterranean
-70
Atlantic
-80
-12
-10
-8
-6
d O (‰)
18
-4
-2
0
Acknowledgements : This work has been performed in the framework of the MICINN Project CGL2009-12977
of the Spanish R&D Programme 2008-2011.
d H (‰ )
-8
-6
d O (‰ )
-4
-2
0
Cáceres
-40
-50
Gargáligas (observed)
Gargáligas (modeled)
REVIP station
LMWL
Trend line
-70
-80
-8
-6
-4
-2
0
Almería
Murcia
-40
Ciudad Real
2
2
d H (‰ )
2
d H (‰)
Díaz-Teijeiro, M.F., Rodríguez-Arévalo, J., Castaño, S., 2009. La Red Española de Vigilancia
de Isótopos en la Precipitación (REVIP): distribución isotópica espacial y aportación al
conocimiento del ciclo hidrológico. Ingeniería Civil, 155: 87-97.
Tortosa/ Valencia
Morón
Almería
Santander
La Coruña
Gerona
Palma
de Mallorca
Cáceres
Zaragoza
Ciudad Real
Madrid
-10
y = 5,0701x - 13,626
R2 = 1
-10
d 18O (‰ )
-20
-80
0 -12
-2
18
-20
-10
REFERENCES
Trend line
d O (‰ )
-60
0
LMWL
0
-10
δ18O distribution in precipitation over
the area of Giribaile´s watersheds.
-4
Ulldecona (modeled)
18
0
Selection of Giribaile´s watersheds .
-40
Yesa (observed)
-50
Yesa (modeled)
18
Giribaile´s water reservoir.
Tortosa
-50
-80
0 -12
-2
y = 6,762x - 1,5753
R2 = 1
-10
2
-30
d H (‰)
2
d H (‰)
Selection of the watersheds corresponding to five water
reservoirs, over a GIS layer showing the fluvial systems of
Spain.
Map of δ18O distribution in precipitation in Spain over which
the areas of the five watersheds are “cut out” to determine
the mean value of δ18O.
Valencia
Murcia
0
y = 6,1415x - 6,5246
R2 = 0,8201
d H (‰)
y = 6,6307x - 2,4366
R2 = 1
-20
LMWL: δ2H = 8,49 * δ18O + 12,4
2
18
-10
-10
0
d O(‰ )
0
Digital map of δ18O distribution in
precipitation in Spain and the REVIP
network, excluding Santa Cruz de
Tenerife station.
-2
Giribaile (observed)
-50
Giribaile (modeled)
-60
REVIP station
LMWL
-70
2
Trend line
-80
-12
-10
-8
-6
-4
-2
0
d O (‰ )
18
CONCLUSIONS
 REVIP´s network contributes to elaborate models and maps of the isotopic distribution of
precipitacion over the Peninsular Spain that may be put into practice on hydrological studies
of lakes and water reservoirs.
 Evaporation is clearly more significant at those water reservoirs whose river basins are
mainly under the influence of warm and dry summer’s climate, specifically at those where
the residence time of water is longer, in the order of several years.
 The methodology used allows characterizing the isotopic content of oxygen-18 in the
precipitation that gives start to the water contribution into the dam.
 Reference isotopic values obtained through this methodology may be used on dam leakage
studies and water balances, specially at those sites where there is a lack of previous
isotopic information.