Estimación de la salinidad en aguas freáticas del área de influencia de la desembocadura del río Sinú-Córdoba, Colombia

Abstract

The dissolved salts in groundwater and proximity to a river and coastal seas are conditions that generate accumulation of salts in the soil. The objective was to study the trend of the salinity of the shallow groundwater in the catchment area of the river mouth of Sinú River in Cordoba - Colombia. The study area of 82 km 2 was divided into four locations near the river mouth of the Sinú River, where 39 observation wells distributed in 25 wells in main vertices with spacing of 2 km apart and 14 auxiliary vertices with spacing 1 km of the main. For the sampling of groundwater two periods were chosen and corresponded to season of dry and rainy seasons. Chemical analysis was performed in the Laboratory of Soil and Water at the University of Córdoba. In the samples were evaluated the electrical conductivity (EC), pH, Ca, Mg, Na, K, HCO 3, CO 3 and SO 4. The data obtained were analyzed by analysis of variance and tests separation of means (Tukey) (p ≤ 0.05). Simple correlation analysis between CE and soluble ions and estimating EC models by the method of regression by Steps (The Stepwise regression procedure) and water classification based on the contribution of each variable in the models. The results indicate that the water is strongly saline in locations near the river mouth of the Sinú River and associated levels to ions Cl, Na and Mg. The CE models calculated for localities have R 2 ≥ 0,94 indicating high reliability for estimating the EC. Also were found that the predominant types of waters are as chloride classified in the rainy season and the dry season not prevails any salt.