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Herrera C, Urrutia J, Gamboa C, Salgado X, Godfrey L, Rivas A, Jódar J, Custodio E, León C, Sigl V, Delgado K, Arriagada E. Evaluation of the impact of the intensive exploitation of groundwater and the mega-drought based on the hydrochemical and isotopic composition of the waters of the Chacabuco-Polpaico basin in central Chile. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 895:165055. [PMID: 37348727 DOI: 10.1016/j.scitotenv.2023.165055] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 06/14/2023] [Accepted: 06/19/2023] [Indexed: 06/24/2023]
Abstract
A hydrogeochemical and isotopic study has been carried out to understand the hydrogeological functioning of a small alluvial aquifer in central Chile in a context of mega-drought and intensive exploitation of its waters. Additionally, two mine tailings dams from porphyry copper mining are situated in the area. The prolonged mega-drought, which has lasted for over thirteen years, has resulted in a significant decrease in rainfall recharge and a drop of up to 50 m in piezometric levels, although no serious groundwater contamination problems have yet been detected, except for a rise in nitrate contents (ranging between 23 and 45 mg/L NO3) attributed to return irrigation. Groundwaters are calcium-bicarbonate and calcium-sodium-bicarbonate in composition. The values of δ18O and δ2H of the alluvial aquifer indicate fractionation by evaporation that would be explained by the recirculation of water that occurs in the agricultural areas of the basin, where the excess irrigation water that go back to the aquifer presents fractionation by evaporation. The δ34S and δ18O of dissolved sulfate point to pyrite oxidation, which could be related to the pyrite present in the copper porphyry and recognized in the Andes Cordillera. The 87Sr/86Sr isotopic values of the alluvial aquifer waters are close to the isotopic fingerprint of the volcanic rocks of the Abanico Formation. However, the water from the wells located further downstream in the basin and close to the tailing dams show δ34S and δ18O of dissolved sulfate and 87Sr/86Sr consistent with Miocene intrusive mineralogies of the copper porphyry type. The groundwater chemistry does not show water seepage from the tailings dam. Therefore, a minor contribution of minerals related to the intrusive rocks is proposed, which would originate from the movement of fine particles by the wind from the dams to the valley floor. The 14C activities indicate that groundwater is recent.
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Affiliation(s)
- Christian Herrera
- Centro de Investigación y Desarrollo de Ecosistemas Hídricos, Universidad Bernardo O'Higgins, Santiago, Chile.
| | - Javier Urrutia
- Centro de Investigación y Desarrollo de Ecosistemas Hídricos, Universidad Bernardo O'Higgins, Santiago, Chile
| | - Carolina Gamboa
- Centro de Investigación y Desarrollo de Ecosistemas Hídricos, Universidad Bernardo O'Higgins, Santiago, Chile
| | - Ximena Salgado
- Centro de Investigación y Desarrollo de Ecosistemas Hídricos, Universidad Bernardo O'Higgins, Santiago, Chile
| | - Linda Godfrey
- Earth and Planetary Sciences, Rutgers University, 610 Taylor Road, Piscataway, NJ 08854, USA
| | - Ariel Rivas
- Centro de Investigación y Desarrollo de Ecosistemas Hídricos, Universidad Bernardo O'Higgins, Santiago, Chile
| | - Jorge Jódar
- Geological and Mining Institute of Spain (IGME), Zaragoza, Spain
| | - Emilio Custodio
- Royal Academy of Sciences of Spain, Spain; Emeritus Professor Groundwater Hydrology Group, Technical University of Catalonia, Barcelona, Spain; Researcher iUNAT, University of Las Palmas de Gran Canaria, Spain
| | - Carolina León
- Centro de Investigación en Recursos Naturales y Sustentabilidad, Universidad Bernardo OHiggins, Santiago, Chile
| | - Vicente Sigl
- Centro de Investigación y Desarrollo de Ecosistemas Hídricos, Universidad Bernardo O'Higgins, Santiago, Chile
| | - Katherine Delgado
- Centro de Investigación y Desarrollo de Ecosistemas Hídricos, Universidad Bernardo O'Higgins, Santiago, Chile
| | - Elisa Arriagada
- Centro de Investigación y Desarrollo de Ecosistemas Hídricos, Universidad Bernardo O'Higgins, Santiago, Chile
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Mondani M, Gizzi M, Taddia G. Role of Snowpack-Hydrometeorological Sensors for Hydrogeological System Comprehension inside an Alpine Closed-Basin. SENSORS (BASEL, SWITZERLAND) 2022; 22:7130. [PMID: 36236229 PMCID: PMC9572276 DOI: 10.3390/s22197130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 09/15/2022] [Accepted: 09/16/2022] [Indexed: 06/16/2023]
Abstract
Groundwater resource assessment and forecasting in mountain areas requires the monitoring of two conditions, local meteorological conditions, and springs' groundwater parameters. The reliability of the monitoring data and conditions are linked to the technical instrumentation, multiparametric probes, and sensors. This paper presents a set of attractive tools and sensors for springs' groundwater resource monitoring and assessment in mountain basins. Data from the combination of weather station sensors with spring flow-rate instruments, installed in the alpine Mascognaz basin, can guarantee an entire understanding of how one set of parameters can affect other results, defining consequential cause-and-effect relationships. Since a large part of the Alpine groundwater bodies are exploited for drinking purposes, understanding the evolution of their rechange processes requires making the right economic and instrumental investments aimed at using them according to forecast predictions and sustainable development goals.
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Identification of Natural and Anthropogenic Geochemical Processes Determining the Groundwater Quality in Port del Comte High Mountain Karst Aquifer (SE, Pyrenees). WATER 2021. [DOI: 10.3390/w13202891] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The Port del Comte Massif (SE, Pyrenees) contains one of the most important vulnerable and strategic karst aquifers for supplying freshwater to the city of Barcelona (Spain). It is a fragile system, whose possible environmental impact is highly conditioned by land use. To improve the hydrogeological knowledge of the system, between September 2013 and October 2015, a detailed fieldwork was carried out for the revision of the geological model, the inventory of water points, and the in situ physico-chemical characterization on major elements and isotopes of up to a total of 43 springs, as well as precipitation water. This paper focuses on the characterization of the geochemical processes that allow explanation of the observed chemical variability of groundwater drained by the pristine aquifer system to determine the origin of salinity. The results show that the main process is the dissolution of calcite and dolomite, followed by gypsum and halite, and a minor cation exchange-like process. Sulfur and oxygen isotopes from dissolved sulfate in the studied springs point out a geogenic origin related to the dissolution of gypsum from Triassic and Tertiary materials, and that the contribution from anthropogenic sources, like fertilizers, is lower. Nitrate in groundwater is not an important issue, with a few localized cases related with agricultural activities. The multidisciplinary approach has allowed the development of a consistent hydrogeological conceptual model of the functioning of the aquifer system, which can be replicated in other places to understand the geogenic character of the hydrogeochemistry.
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Jódar J, Herms I, Lambán LJ, Martos-Rosillo S, Herrera-Lameli C, Urrutia J, Soler A, Custodio E. Isotopic content in high mountain karst aquifers as a proxy for climate change impact in Mediterranean zones: The Port del Comte karst aquifer (SE Pyrenees, Catalonia, Spain). THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 790:148036. [PMID: 34102446 DOI: 10.1016/j.scitotenv.2021.148036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/18/2021] [Accepted: 05/21/2021] [Indexed: 06/12/2023]
Abstract
The objective of this work is to characterize the impact of climate change in the karst aquifer of the Port del Comte Massif (PCM). Six regional climate models (RCMs) from CLYM'PY Project are used to analyse the magnitude and trends of changes on precipitation and temperature (RCP4.5 and RCP8.5 scenarios) and how these changes propagate through the hydrogeological system as groundwater resources availability and the associated water isotopic content. The study uses the RCMs climate change forcings as input data to a combination of (1) a semi-distributed hydrological model for simulating the hydrodynamical response of the aquifer, and (2) a lumped parameter model for simulating the isotopic content in groundwater at the outlet of the aquifer. A mean decrease of 2.6% and 1.9% in yearly precipitation and a mean increase of 1.9 and 3.1 °C in average temperature is expected in PCM at the end of the 21st century in the RCP4.5 and RCP8.5 scenarios, respectively. This climate signal entering the hydrogeological system results in a mean decrease in recharge of 3.9% and 0.5% from rainfall and of 59.3% and 76.1% from snowmelt, and a decrease of 7.6% and 4.5% in total system discharge, but also generates an isotopic enrichment in groundwater discharge (δ18OGW) of 0.50‰ and 0.84‰, respectively. Moreover, from a long-term (2010-2100) perspective, the mean trend in δ18OGW is 0.7‰/100 yr and 1.2‰/100 yr for RCP4.5 and RCP8.5, respectively, resulting in easily measurable annual lapse rates with the current analytical methods.
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Affiliation(s)
- J Jódar
- Geological Institute of Spain (IGME), Spain.
| | - I Herms
- Àrea de Recursos Geològics. Institut Cartogràfic i Geològic de Catalunya (ICGC), Barcelona, Spain
| | - L J Lambán
- Geological Institute of Spain (IGME), Spain
| | | | - C Herrera-Lameli
- Centro de Investigación y Desarrollo de Ecosistemas Hídricos, Universidad Bernardo O'Higgins, Santiago, Chile
| | - J Urrutia
- Centro de Investigación y Desarrollo de Ecosistemas Hídricos, Universidad Bernardo O'Higgins, Santiago, Chile; HEUMA, Department of Mining Engineering, Universidad de Antofagasta, Antofagasta 2030, Chile
| | - A Soler
- Grup MAiMA, SGR Mineralogia Aplicada, Geoquímica i Geomicrobiologia, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Universitat de Barcelona (UB), C/Martí i Franquès s/n, 08028 Barcelona, Spain
| | - E Custodio
- Groundwater Hydrology Group, Dept. Civil and Environmental Eng., Technical University of Catalonia (UPC). Royal Academy of Sciences, of Spain
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Figueroa R, Viguier B, Taucare M, Yáñez G, Arancibia G, Sanhueza J, Daniele L. Deciphering groundwater flow-paths in fault-controlled semiarid mountain front zones (Central Chile). THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 771:145456. [PMID: 33736186 DOI: 10.1016/j.scitotenv.2021.145456] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 01/22/2021] [Accepted: 01/23/2021] [Indexed: 06/12/2023]
Abstract
The Mountain-Block Recharge (MBR), also referred to as the hidden recharge, consists of groundwater inflows from the mountain block into adjacent alluvial aquifers. This is a significant recharge process in arid environments, but frequently discarded since it is imperceptible from the ground surface. In fault-controlled Mountain Front Zones (MFZs), the hydrogeological limit between the mountain-block and adjacent alluvial basins is complex and, consequently, the groundwater flow-paths reflect that setting. To cope with the typical low density of boreholes in MFZs hindering a proper assessment of MBR, a combined geoelectrical-gravity approach was proposed to decipher groundwater flow-paths in fault-controlled MFZs. The study took place in the semiarid Western Andean Front separating the Central Depression from the Principal Cordillera at the Aconcagua Basin (Central Chile). Our results, corroborated by field observations and compared with worldwide literature, indicate that: (i) The limit between the two domains consists of N-S-oriented faults with clay-rich core (several tens of meters width low electrical-resistivity subvertical bands) that impede the diffuse MBR. The "hidden recharge" along the Western Andean Front occurs through (ii) focused MBR processes by (ii.a) open and discrete basement faults (mass defect and springs) oblique to the MFZ that cross-cut the N-S-oriented faults, and (ii.b) high-hydraulic transmissivity alluvial corridors in canyons. Alluvial corridors host narrow unconfined mountain aquifers, which are recharged by indirect infiltration along ephemeral streams and focused inflows from oblique basement faults. This study also revealed seepage from irrigation canals highlighting their key role in the recharge of alluvial aquifers in the Central Depression. The proposed combined geophysical approach successfully incorporated (hydro)geological features and geophysical forward/inverse modelling into a robust hydrogeological conceptual model to decipher groundwater flow-paths in fault-controlled MFZs, even in the absence of direct observation points.
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Affiliation(s)
- Ronny Figueroa
- Departamento de Ingeniería Estructural y Geotécnica, Pontificia Universidad Católica de Chile, Santiago, Chile; Centro de Excelencia en Geotermia de los Andes (CEGA), Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile
| | - Benoît Viguier
- Centro de Excelencia en Geotermia de los Andes (CEGA), Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile; Instituto de Ciencias de la Ingeniería, Universidad de O'Higgins, Rancagua, Chile
| | - Matías Taucare
- Centro de Excelencia en Geotermia de los Andes (CEGA), Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile; Departamento de Geología, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile.
| | - Gonzalo Yáñez
- Departamento de Ingeniería Estructural y Geotécnica, Pontificia Universidad Católica de Chile, Santiago, Chile; Centro de Excelencia en Geotermia de los Andes (CEGA), Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile
| | - Gloria Arancibia
- Departamento de Ingeniería Estructural y Geotécnica, Pontificia Universidad Católica de Chile, Santiago, Chile; Centro de Excelencia en Geotermia de los Andes (CEGA), Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile
| | - Jorge Sanhueza
- Departamento de Ingeniería Estructural y Geotécnica, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Linda Daniele
- Centro de Excelencia en Geotermia de los Andes (CEGA), Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile; Departamento de Geología, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile
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