Hydrogeological characterization of the River Basin Las Marías, Los Cobanos, Sonsonate, El Salvador

Abstract

Hydrogeological characterization of the river basin Las Marias, Los Cóbanos department of Sonsonate, El Salvador, was performed with the aim of evaluate the aquifer system. The analysis included the use of hydrogeochemical, geophysical tools, and lithological information available in the study area, which allowed us to propose a conceptual model of the aquifer and exclude the presence of seawater intrusion. The existence of two aquifers was determined in the area, one of them is a shallow aquifer, Mid production with a variable thickness of 0 meters to 20 meters, and is use in the area for water supply through dug wells with depths not exceeding 6 meters and diameters up to 1,5 meters. Analysis of the chemical data determined that there are anthropogenic pollution sources in the area that affect the water quality. Another aquifer was detected with the vertical electrical tests and which are known to exist by private drilled wells supplying hotels, farms and private properties in the area. A water balance shown that the 1739 mm annual rainfall, 70,6% equivalent to 1217 mm corresponds to actual evapotranspiration, 13% (226 mm) belongs to the retention by vegetation and the remaining 16,4% (278 mm) represents the water recharge zone.