Caracterización de las familias hidrogeoquímicas en el aquífero costero de Telde (Gran Canaria)

Abstract

An area of about 75.5 km2 has been studied. It supports a high population density (ca. 1000 inh./ km2). Traditionally agricultural, its groundwater exploitation is very important, with 145 water sources, mainly large diameter wells (dephts ranging from 15 to 239 m). The main water use is agriculture, but also human supply. The aquifer system from ilch water is drawn is complex: Miocene phonolite lavas and ashflow deposits at the North, sediments of Las Palmas Detritic Formation in the central part and Recent Basalts a t the South. Hydrogeochemical studies of groundwater have allowed to characterize different groundwater families, depending on the exploited materials and /or the existence of some modifying phenomena. HC03-Mg water and CI- HCO 3-Na water are related with basaltic and phonolitic materials respectively. Irrigation return waters produce S0 4-Na or HC03-CI-Na water, water supply system leaks generate CI-SO4-Na-Mg water, marine intrusion produces CTS04-Na water in the coastal strip and Cl-ivtg water situated at the South can be due to salinity of recharge due to aridity or water mineralization because of the volcanic C 0 2 present in the aquifer