Assessment of groundwater quality in west metropolitan of Iran: An application of GIS and modeling

Abstract

Groundwater resources in special have been applied for drinking water use versus surface water in Iran. However, this groundwater withdrawal has not been monitored for its level and quality. The present study aimed at determining the qualitative changes of Hamedan groundwater resources using the Kriging and analysis of quality assurance approach. To investigate the spatial variations of water quality in Hamedan, the following physical parameters were taken into consideration: total dissolved solid and electrical conductivity; chemical agents including calcium, magnesium, sodium adsorption ratio, iron, fluoride, sulfate, nitrate, phosphate; residual concentrations of pesticides in drinking water, including organochlorine (difenoconazole and permethrin), organophosphate (chlorpyrifos, diazinon, and malathion), and pyrethroids (fenvalerate); and heavy metals including cadmium, lead, arsenic, mercury, chromium, copper, and zinc. The geographic information system (ArcGIS10.4) was used to draw the isopotential maps of the resources. Schuler, Piper, and Durov diagrams as well as AqQA software were used to determine the water quality. According to Shuler's diagram, samples of drinking water in Hamedan vary from moderate to good in terms of quality. The concentration of physicochemical parameters in the north, northwest, and northeast of Hamedan was higher than the World Health Organization (WHO) guidelines. The residual concentrations of pesticides, arsenic, mercury, chromium, and cadmium were lower than the WHO guidelines. However, the concentrations of copper and zinc in northern Hamedan were higher than the guidelines. According to the geological map of the plains of Hamedan, it can be concluded that the source rock mainly consists of dolomite and igneous rock is made of alkaline-basaltic feldspar. Variations in the chemical composition of drinking water in Hamedan depend on the amount of precipitation, soil, water harvesting, excessive use of fertilizers and human activities.

Investigation of Residual Concentration of Organochlorine, Organophosphorus, and Carbamate Pesticides in Urban Drinking Water Networks of Hamadan Province, Iran

“…In addition, the European Union has set the maximum allowable concentration for the total pesticide residues in drinking water sources at 0.5 μg/L, and for these pesticides at 0.1 μg/L separately (16,28). As mentioned earlier, the best and closest international standard to Iran's national standards are the WHO guidelines.…”

“…Hamadan is the most populous county of the province and Hamadan city -the center of the county, is also the capital of the province. Hamadan province, with its abundant rainfall and suitable environmental conditions, has been well-developed in the fields of agriculture and horticulture turning Tuyserkan and Bahar counties into the centers of walnut and potato production in Iran, respectively (15,16).…”