Sources of surface water for the Soncor ecosystem, Salar de Atacama basin, northern Chile

Abstract

The Salar de Atacama is located in the most arid desert in the world. Despite its extreme conditions, it has many ecosystems of high ecological value. The Soncor ecosystem, a sequence of lagoons, is the most important environment of the region as it acts as the centre for the breeding of the Andean Flamingo. This salt flat also contains significant mining deposits and is an important water source for the region. Freshwater and brine-enriched in lithium and potassium-are being pumped from the aquifers near to the Soncor ecosystem, which has so far not been greatly affected by this groundwater extraction. However, there is a potential risk that future anthropogenic effects may disturb this fragile environment. The objective of this study is to determine the origin of the water sources of the Soncor ecosystem so as to adequately manage its water resources. Three hypotheses previously proposed in the technical literature were investigated in order to determine proactive actions to protect this fragile ecosystem. The study utilized classic hydrogeological techniques, such as the construction of stratigraphic profiles, piezometric maps and stream gauging, combined with less-common isotopic techniques, such as the Il existe cependant un risque que cet environnement fragile ne soit affecté par les activités anthropiques futures. La présente étude a pour objectif de déterminer l'origine des eaux de l'écosystème du Soncor afin de gérer convenablement ses ressources en eau. Les recherches ont porté sur trois hypothèses proposées dans la littérature technique, afin de proposer des actions efficaces pour la protection du système. L'étude a mis en oeuvre des méthodes hydrogéologiques classiques comme la construction de profils stratigraphiques, la cartographie de la piézométrie et le jaugeage des cours d'eau, et des techniques isotopiques plus innovantes comme l'étude du rapport 87 Sr/ 86 Sr. Les résultats confirment l'hypothèse selon laquelle l'origine des eaux du Soncor est associée à des apports d'eau souterraine provenant de la partie orientale du salar, dans la zone Nord du bassin.

Rapid recharge of fresh water to the halite‐hosted brine aquifer of Salar de Atacama, Chile

“…Throughout this period, the transitional pool area remains relatively small compared with brackish lagoons. The lagoons demonstrate a distinct seasonal change in area consistent with increases and decreases in open water evaporation rates driven by solar insolation (Salas et al , ; Ortiz et al , ). We have measured seasonal fluctuations in major element, lithium, and δ 2 H–H 2 O and δ 18 O–H 2 O, which are correlated with changes in relative size of the lagoons (Munk et al , ).…”

“…The eastern margin of SdA is also characterized by an extensive transition zone and lagoon complexes, and therefore may operate similarly. Salas et al (2010) and Ortiz et al (2014) both show that a small fraction (<5%) of the water entering the Chaxa lagoon system in the northeast part of the Salar becomes recharge to the halite aquifer brine.…”

Regional groundwater flow and accumulation of a massive evaporite deposit at the margin of the Chilean Altiplano

“…The average Na concentration at each inflow site is used to estimate the average Na composition of modern GW DIS and R. Modern R rates from Dirección General de Aguas [2013] and our best estimates of shallow (<200 m depth) groundwater inflow are used to estimate the weighted-average Na concentration (mg/L) of modern inflow. Shallow near-basin floor (slightly upgradient from zones of ET) groundwater flow to SdA (GW DIS ) is estimated by dividing the basin into five zones and applying Darcy's law based on hydraulic gradients collected in January 2014 as part of this study and by Salas et al [2010] and Ortiz et al [2014] and estimates of hydraulic conductivity and aquifer geometry (supporting information).…”

San Pedro De Atacama Y La Cuestión Tiwanaku en El Norte De Chile: Impresiones a Partir De Un Clásico Estudio Cerámico Y La Evidencia Bioarqueológica Actual (400-1.000 D.C.)

“…Por ejemplo, observamos algunos valores bastante enriquecidos en 18 O, a veces alcanzando valores sobre 0‰, a pesar que los ayllus atacameños se encuentran a unos 2.400 msm. Esto debido seguramente al complejo sistema de aguas que caracteriza al desierto, siendo en este caso que los dos principales ríos de la localidad adquieren sus aguas tanto de las lluvias ocurridas en el verano y por los deshielos además de cursos subterráneos de diferentes fuentes cordilleranas (Aravena 1995;Magaritz et al 1989;Ortiz et al 2013). Por otra parte, la variación de los isótopos de oxígeno también depende de las condiciones climáticas del momento, siendo muy afectados por cambios extremos de temperatura y humedad.…”