Abstract

CARRERA-VILLACRES, David Vinicio et al. Qualitative and Quantitative Salinity of the Santa María-Verde River Hydrographic System, Mexico. Tecnol. cienc. agua [online]. 2015, vol.6, n.2, pp.69-83. ISSN 2007-2422.

This investigation took place in the Santa Maria-Verde River hydrographic system in order to identify the evolution of the salinity of irrigation water. It included both a quantitative (electrical conductivity) and qualitative (calculated using the sodium and magnesium adsorption ratio) analysis in order to predict effects on soil and crops. The investigation used a non-experimental, descriptive cross-sectional design in which 69 stations were sampled from winter 2009 to spring and autumn of 2010. Ten measurements were taken for each water sample, cations, anions, pH and electrical conductivity (CE). An alkalinity model was used to determine the evolution of the waters, which was experimentally verified by re-concentration of salts through evaporation. The saturation index (SI) and changes in the sodium adsorption ratio (SAR and SAR_adj) were calculated. The salinity of most of the rivers in the Santa Maria-Verde River hydrographic system was classified as high or very high, according to the quantitative analysis. The most critical qualitative salinity was that of magnesium, as compared to sodium, even with the precipitation of calcite. The waters evolved from calcium sulfate to magnesium and sodium sulfate. There was a trend of increasing concentrations and changes in the type of salinity of the waters in the Santa Maria-Verde River hydrographic system, which affects the soils and crops.

Keywords : sodium; magnesium; evolution of water; geostatistical.