Factores que inciden en el agotamiento y la contaminación por intrusión marina en el acuífero costero de La Yarada, Tacna, Perú

Abstract

The La Yarada aquifer, located in the Tacna region, is the most arid zone of the Peruvian coast, characterized by the scarcity of water resources. For several decades this situation resulted to the use of groundwater for the development of agriculture and other economic activities. However, due to the lack of a program for operating the aquifer it is being overexploited generating a permanent lowering of water tables, compromising their non-renewable reserves, which has caused the phenomenon of seawater intrusion due to the high concentration of groundwater wells operating in the zone next to the coastline. In this common sense, it is intended to determine the factors that affecting the depletion and contamination by seawater intrusion, characterizing the aquifer's hydrogeology and explaining the correlation between geology, hydrochemistry, geophysics and other tools used to characterize aquifers. A critical area of groundwater quality degradation in the aquifer was determined, comprising an approximate 131 km2 (60 km2 by marine intrusion) with very high values of sodium, indicating a gradual increase of this ion in response to the greater penetration of the saline wedge in areas closer to the coast and by other factors in other areas. There is also overlap between the direction of groundwater flow and the increase in chloride content, although some deviations are locally appearing. According to the geoelectric sections, there is a lower layer with low and very low resistivity’s, which indicates that the aquifer is highly mineralized in the littoral zone, a situation that denotes to the seawater intrusion processes.