Evaluating Salinity in Shallow and Deep Aquifers of Gorganrood Basin, Iran

Abstract

Increasing groundwater salinity in countries facing water scarcity has raised severe environmental and health concerns. One of the best ways to prevent groundwater pollution is to study groundwater quality's spatial variation and identify vulnerable aquifer areas. The aim of the present study was to evaluate the salinity of groundwater in shallow and deep aquifers of the Gorganrood basin. To achieve this goal, values of electrical conductivity of groundwater in mentioned aquifers were measured in situ for wet and dry periods. According to obtained results, groundwater salinity in shallow aquifer is considerably greater than that in the deep aquifer. Moreover, the salinity of groundwater in both aquifers (shallow aquifer in particular) for the wet period has been diminished compared to that for the dry period. the maximum electrical conductivity associated with the shallow wells, is related to the well of Kuchek Khortum, which is 8350 µmho/cm due to the presence of sediments containing high-solubility materials. fine grain content of sediment and, consequently, the rise of water due to the capillary force and its evaporation, and the remaining salts in sediments are salinity factors. Also, the operation of Caspian fault has transmitted deep water to the surface aquifers and has caused water salinity in these areas. deep wells In the south of the basin with the lowest electrical conductivity feeding rivers' entry improves water quality and reduces electrical conductivity. In the north of the basin, the water quality is reduced due to the desert area's passage, where the groundwater level is relatively....