Exemple d'etude geochimique et isotopique de circulations aquiferes en terrain volcanique sous climat semi-aride (Amurga, Gran Canaria, Iles Canaries)

Estimating Natural Recharge by Means of Chloride Mass Balance in a Volcanic Aquifer: Northeastern Gran Canaria (Canary Islands, Spain)

“…The highest values corresponded to the samples located near the coast given the incorporation of dust and chloride dry deposition from the marine aerosol. The bulk chloride deposition values obtained in this study were similar to the results obtained in previous studies conducted in Gran Canaria: between 4 and 5 g·m in coastal areas [24,25,34]. Atmospheric chloride deposition and other solutes play an important role in the climatic salinization of groundwater through evapoconcentration, especially when R/P is low (arid zones), which is the case for the Fuerteventura Island [22] and southern areas of the Gran Canaria Island.…”

“…(2) Las Cañadas aquifer, on the central Tenerife Island, when five rain collection stations were in operation in hydrologic year [2005][2006]; the average recharge was estimated to be 215 mm/year (44% of precipitation) [23]; (3) La Aldea aquifer [24], under semiarid conditions; (4) on La Gomera Island with a detailed groundwater chloride map, corrections were applied for mixing due to slope effects and after assuming deposition rates that had been extrapolated from other islands [5]; (5) the Amurga Fonolitic Massif on the southeastern part of Gran Canaria Island using chloride deposition [25] and 13 C-corrected 14 C data in a sloping aquifer to obtain the average recharge rate. This resulted in an areal average of about 4 mm/year, from less than 1 mm/year on the coast to 12 mm/year at the top of the wedge-shaped massif [5].…”

Groundwater Assessment at Santiago Island (Cabo Verde): A Multidisciplinary Approach to a Recurring Source of Water Supply

“…From the isotopic point of view, it is possible to identify the salts origin within the groundwater system, since the mechanisms of dissolution or leaching of salts will not result in any change in the water's isotopic composition, yet observed in seawater intrusion processes (Gasparini 1989;Zouari et al 1999). The isotopic approach is particularly useful near coastal areas where all the salinity was ultimately originated from the marine environment, so that, little chemical distinction exists between salinity originating from sea-spray or from direct sea-water encroachment, from surface lagoons or from interstitial waters.…”

Estimación de la escorrentía superficial para el cálculo de la recarga a los acuíferos del macizo kárstico de los Ports de Beseit (Tarragona, España) combinando balance de agua en el suelo y análisis de hidrogramas de caudales

“…Estas estimaciones parten de un modelo conceptual de funcionamiento hidrogeológico, basado en los datos y observaciones disponibles y en lo posible validado mediante estudios y consideraciones hidrogeoquímicas e isotópicas ambientales (Allison, 1988;Gasparini et al, 1990;Allison et al, 1994;Wood & Sanford, 1995;Hornero et al, 2013).…”