Ricardo Oyarzún

A Rich Vein? Mining and the Pursuit of Sustainability†

The removal of a nonrenewable natural resource such as metals or petrochemicals hardly meets the definition of “sustainable”. However the methods used to extract the materials can be designed for overall environmental protection. Theoretically controllable variables include water use, transportation methods, and potential remediation/landscape alteration for the postclosure period. Further, in the case of metals, recycling means that the long-term sustainability of such resources can be realized. Amezaga et al. review how mining practices have evolved to consider sustainability over the last few decades and remark on what challenges still need to be overcome.

Stakeholder participation within the public environmental system in Chile: Major gaps between theory and practice

The main objective of this paper is to present a critical analysis of the stakeholder participation process within the Environmental Impact Assessment System in Chile, after ca. 14 years of being enforced. This analysis is sustained by the description and analysis of the stakeholder participation possibilities in a representative rural area of North-Central Chile. The Environmental Basis Act 19300, enacted in 1994, considers the participation of the local community in the environmental impact assessment of new projects. However, this possibility is very limited and difficult to exert, often resulting in frustration for the participants. This is due to a number of reasons, such as the imbalance of resources and knowledge among the majority of participating communities and project proponents, the complexity and administrative and legal constraints to participation, and the dominant interest of the Central Government in approving investments, specifically in energy and natural resources related projects, which generate wealth and jobs. Also, the States rush to develop Internet-based communication and management systems has built a barrier for poor, traditional communities. This factor is clearly reflected in the case study considered. Results show that there is generally a significant lack of knowledge about institutions and participation tools. From this base, we intend to raise concern on these selected aspects that could be addressed to improve the effectiveness of the existing framework, both in Chile and in other developing countries, where immature environmental impact assessment and public management systems face similar pressures in relation to the sustainable use of their natural resources. Finally, some basic steps are proposed in order to make the community participation an effective tool for sustainable development.

Statistical downscaling of precipitation and temperature in north-central Chile: an assessment of possible climate change impacts in an arid Andean watershed.

Abstract Downscaling of atmosphere–ocean general circulation models (AOGCMs) is necessary to transfer predictions of potential climate change scenarios to local levels. This is of special interest in dry mountainous areas, which are particularly vulnerable to climate change due to risks of reduced freshwater availability. These areas play a key role in hydrology, since they usually receive the highest local precipitation amounts, which are then stored in the form of snow and glaciers. The performance and ability to simulate extreme events of a statistical downscaling model (SDSM) were tested in the arid Upper-Elqui watershed, Chile. Thereafter, future temperature and precipitation seasonal trends along with agro-hydrological indices were analysed for the HadCM3 A2a and B2a scenarios. Maximum and minimum temperatures for both linear trends and extreme events were simulated accurately. However, the results show that SDSM was not a very robust method for the simulation of precipitation. Nevertheless, future trends and indices indicate possible strong inter-seasonal perturbations. Citation Souvignet, M., Gaese, H., Ribbe, L., Kretschmer, N. & Oyarzún, R. (2010) Statistical downscaling of precipitation and temperature in north-central Chile: an assessment of possible climate change impacts in an arid Andean watershed. Hydrol. Sci. J. 55(1), 41–57.

Application of water quality indices and analysis of the surface water quality monitoring network in semiarid North-Central Chile

Surface water quality has increasing importance worldwide and is particularly relevant in the semiarid North-Central Chile, where agriculture and mining activities are imposing heavy pressure on limited water resources. The current study presents the application of a water quality index in four watersheds of the 29°–33°S realm for the period 1999–2008, based on the Canadian Council of Ministers for the Environment approach and the Chilean regulation for irrigation water quality. In addition, two modifications to the index are tested and a comprehensive characterization of the existing monitoring network is performed through cluster analysis. The basins studied show fairly good water quality in the overall, specially the Limarí basin. On the other hand, the lower index values were obtained for the headwaters of Elqui, associated with the El Indio mining district. The first modification of the indicator (i.e., to consider parameters differentially according to their effect on human health or the environment) did not produce major differences with respect to the original index, given the generally good water quality. The second modification (i.e., to consider as threshold values the more restrictive figures derived from a set of regulations) yielded important differences in the indicator values. Finally, an adequate characterization of the monitoring network was obtained. The results presented spatial coherence and the information can be used as a basis for the optimization of the monitoring network if required.

Hydro-meteorological trends in semi-arid north-central Chile (29–32°S): water resources implications for a fragile Andean region

Abstract Changes in hydro-meteorological historical records are of considerable importance for future planning. This study analyses trends of hydro-climatological indices of annual and seasonal precipitation, temperature and discharge in the “Norte Chico” region of Chile (29–32°S), located in the Central Andes. It addresses how these trends possibly impacted on the water resources in a nival regime, typical for arid mountainous regions. Homogenous records were tested against monotonic trends using the non-parametric rank-based Mann-Kendall test. The results suggested, at a very high confidence level, a strong warming signal trend over recent decades, consistent at the annual and seasonal levels. Furthermore, warmer days are observed in summer, especially at higher elevations. The region also experienced a shift in the rainy season over the last 42 years. However, an increase in precipitation was observed over recent decades, whereas an annual decrease was the general tendency when the whole century was considered. Changes in discharge were not unequivocal and glacier retreat has been compensated for possibly by an increase in snowmelt in recent years. Hence, in an under-studied area, from the hydrological perspective, this work provides some insights for a better understanding of changing hydrological processes in the mid-latitude Andes Cordillera. Editor Z. W. Kundzewicz Citation Souvignet, M., Oyarzún, R., Verbist, K.M.J., Gaese, H. and Heinrich, J., 2012. Hydro-meteorological trends in semi-arid north-central Chile (29–32°S): water resources implications for a fragile Andean region. Hydrological Sciences Journal, 57 (3), 479–495.

Water Quality Assessment of the Mining-Impacted Elqui River Basin, Chile

Multivariate data analysis techniques were used to identify the interrelationships between the physical–chemical analyses of 22 parameters sampled monthly from 1991 to 2007 at 16 monitoring stations along the Elqui river and its tributaries to characterize the scale of the geogenic and anthropogenic impacts on the river’s water quality. Principal component analysis was used to identify the differences and similarities between variables in the watershed. Factorial indices, computed to highlight the sections of the river and tributaries more influenced by hydrothermal, mining or agricultural activities, made it possible to synthesize groups of parameters with similar characteristics into a single value.ZusammenfassungVon 1991 bis 2007 wurden an 16 Beobachtungstationen entlang des Elqui-Flusses und seinen Zuflüssen monatlich 22 physiko-chemische Parameter gemessen. Der Grad geogener und anthropogener Einflüsse auf die Wasserqualität wurde mit multivariaten Analysen untersucht. Hauptkomponentenanalyse wurde angewendet, um Unterschiede und Ähnlichkeiten zwischen Variablen in dem Wassereinzugsgebiet zu identifizieren. Um Abschnitte des Flusses und seiner Zuflüsse mit stärkerem Einfluß hydrothermaler, bergaulicher oder landwirtschaftlicher Aktivitäten hervorzuheben, wurden faktorielle Kennzahlen berechnet. Damit war es möglich, Gruppen von Parametern ähnlicher Besonderheiten in einen Einzelwert zusammenzuführen.ResumenSe utilizaron técnicas de análisis multivariante para identificar las relaciones entre los análisis de 22 parámetros fisicoquímicos obtenidos mensualmente desde 1991 hasta 2007 en 16 estaciones de monitorio a lo largo del Río Elqui y sus tributarios, en función de caracterizar de la escala de los impactos geogénicos y antropogénicos sobre la calidad del agua del río. El análisis de componentes principales (PCA) fue usado para identificar las diferencias y similitudes entre variables de la cuenca. Los índices factoriales, estimados para destacar las zonas del río y sus tributarios más influida por las actividades minerales, hidrotérmicas o agrícolas, permitieron reunir grupos de parámetros con similares características dentro de un solo valor.抽象化学水质监测指标之间的关系,以研究地质成因和人类活动作用对流域水质的影响程度。利用主成分分析法(PCA)识别了流域内各变量之间的差异与相似性。利用因子分析突出了埃尔基河及其支流受热液、采矿和农业活动的影响程度,使具有相似特征的多元变量转化为单一变量成为可能。

Natural factors and mining activity bearings on the water quality of the Choapa basin, North Central Chile: insights on the role of mafic volcanic rocks in the buffering of the acid drainage process.

This contribution analyzes water chemical data for the Choapa basin, North Central Chile, for the period 1980–2004. The parameters considered are As, Cu Fe, pH, EC, SO

Evaluating piezometric trends using the Mann-Kendall test on the alluvial aquifers of the Elqui River basin, Chile

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Surface water quality in a sulfide mineral‐rich arid zone in North‐Central Chile: Learning from a complex past, addressing an uncertain future

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Where does the water go? Understanding geohydrological behaviour of Andean catchments in south-central Chile

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