Observaciones hidrogeológicas en el área urbana de Granada

Abstract

A number of hydraulic tests, as well as monitoring of groundwater level and physico-chemical variables, have been carried out -since their construction in August 2000- in two adjacent wells located inside the urban area of Granada, which extends over the eastern border of the Vega de Granada alluvial aquifer.

Other nearby wells out of the urban area were also monitored. The results indicate a phreatic (S=0,25), transmissive (T =3000 m2/d) aquifer, with flow velocity values of around 4 m/d. Clayey levels, relatively abundant in this sedimentary environment, induce the presence of a perched groundwater level that seems to leak into a deeper one through the gravel pack of one of the boreholes. Groundwater in the studied area has electrical conductivity in the range 600-1300 mS/cm, and bicarbonate-sulfate calcium-magnesium type. The recharge from the main stream is characterized by low mineralization values (300 mS/cm). The infiltration of urban wastewater must account for the relatively high nitrate contents -as well as for some microbiological indices- found in the water of the studied wells