Investigation of hydrogeochemical factors and groundwater quality assessment in Marand Municipality, northwest of Iran: A multivariate statistical approach

摘要

Groundwater is the only major source for drinking water, agricultural and industrial uses in Marand Municipality, so guaranteeing the quality of the water is highly needed in this region. In this study, data sets from two sampling periods (spring and summer) were used to evaluate the chemical quality of water and to study effective factors and hydrogeochemistry processes in Marand groundwater. While carrying out factor analysis, three major parameters of groundwater composition were extracted. According to the Cluster dendrogram the highest similarity exists between HCO32- and Mg2+ in the groundwater of the region. Piper diagram and correlation matrix results indicated that the main type of groundwater was bicarbonate with influential role of alkaline earths. Studying isoelectrical conductivity, total dissolved solid contours, and a pie chart in hydrochemical maps shows an increase in EC, TDS and chloride concentration in the groundwater located in the northeast of the region. Changes in the spatial interpretation of the groundwater parameters indicated that the quality and geochemical characteristics of groundwater had a close correlation with topography, geology and hydrograph of Marand plain. Samples which have been obtained from southern parts of the region (near to aquifer recharge center) showed very suitable quality, but the composition of the groundwater changes in the northeast because of an increase of ionic constituents and the existence of fine grain sediments in aquifer zones. We can conclude that factors such as groundwater flow paths, water level increase and human influences made this part of the region sustainable. In this case human influences can include anthropogenic inputs such as urban wastewater and agricultural activities.