Assessment and comparison of the spring and well water resources quality for Drinking and Irrigation Purposes (Case study: East of Gorgan plain

The present study was conducted in order to evaluate and compare the quality of underground water resources (springs and wells) in the eastern part of Gorgan Plain in terms of potability and irrigation in a 10-year period. In this research, the results of chemical analysis of 14 wells and 8 springs were used. Water quality index (WQI), Schuler's diagram and some criteria and standards were used to evaluate the quality of drinking water sources. Electrical conductivity, corrosion ratio, magnesium ratio, sodium absorption ratio, soluble sodium percentage, permeability ratio and overall ratio were used in the irrigation section. Then, the zoning of some effective parameters and indicators in each section was done in the GIS environment using the IDW method. Based on the WQI index, the quality of all springs and wells on the edge of the highlands is in the excellent category, but as you move away from the plain, the quality of some wells varies from good to poor. Based on the concentration of some hydrochemical parameters, standards and Schuler's diagram, except for one remaining well, the studied water sources are of suitable quality for drinking. In the irrigation sector, based on the Wilcox diagram, sodium absorption ratio, salinity risk, residual sodium carbonate index and overall ratio, water from wells in the west of the region should be used with caution. In general, the quality of spring water in both drinking and irrigation sectors is much better than well water.