EN
In most coastal areas in Mexico, there is an increase in housing development and facilities for tourism, consequently resulting in a negative impact on the environment. Due to this, an awareness of the critical role of groundwater in sustaining coastal populations, economies, and ecosystems is growing. The coastal zone of Sinaloa State is classified as an area with a high presence of saline groundwater in Mexico. The present work was performed in the Las Glorias Beach, Guasave, Sinaloa, Mexico. The results of the analysis of 19 soil and groundwater samples indicate the predominance of sandy soil and a wide range of water salinity, from slightly saline to brine. An electromagnetic profiling (EMP) survey was performed at the study site showing a low apparent electrical conductivity zone parallel to the coastline as indicative of the possible presence of fresh and/or slightly saline water. Apparent electrical conductivity values were compared with electrical conductivity values measured in groundwater samples collected in wells, resulting in a positive linear correlation (R = 0.97). This linear relation is explained by a φ - ξ electromagnetic analytic model when 5.36 ≤ σₐ ≤ 85.87 mS/cm. The linear relation was used to recalculate the apparent electrical conductivity values from EMP survey into electrical conductivity values of groundwater and, therefore, TDS values. The TDS map indicates the presence of a barrier of fresh/slightly saline groundwater parallel to the coastline that keeps a fragile balance that prevents the advance of saltwater intrusion from the sea of Cortés and from brine zones located in the northern part of the site. The advance of erosion in Las Glorias Beach exposes the vulnerability of the aquifer to the saline intrusion to be advancing in time, which has affected the zone economically and socially.