Evaluation of Chemical Quality and Salinity Origin of Groundwater in a Semi Aried Area; Seyed Gholi Region Saveh, Iran

Background & Aims of the Study: In recent years, groundwater resources of Seyed Gholi in Saveh area has been deteriorated because of some factors such as unconventional withdrawal in order to agricultural and industrial uses. This study has been conducted to evaluation of chemical quality and salinity origin of groundwater in this region. Materials & Methods: In order to survey on salinity of water in this region, data from 6 sampling wells (2002-2011) has been used. In first step by collecting valid information about the chemical quality of related aquifer, investigation on fluctuation trends of ions concentrations of Ca, Mg, Na, HCO3, Cl, SO4, from 2002 to 2011 has been conducted. Then, pH and EC has been surveyed for ten years (2002-2011) to determine the general chemical quality of region groundwater. Finally, changes trends of ions and water salinity has been plotted on descriptive diagrams, piper, statistical models and other plans. Results: Results show that the average ion concentrations of sulfate and chloride are 803.52 and 579.72 mg/l, the average amounts of EC and TDS are 3665.70µm/cm & 2152.96 mg/l respectively in the period of 2002-2011. In other words, the average concentrations of sulfate and chloride iones have increased from 750.24 and 619.12 to 890.4 and 635.095 mg/l respectively and also TDS have changed from 2076.69 to 2357 mg/l in the period of 2002-2011. Conclusion: It has been concluded that descending trend of flow rate and increasing of ion concentration of sulfate and chloride indicated that quality of water in this region is not desirable which will lead to the deterioration of chemical quality of water for various uses. If the current conditions continue, the water will be non- potable.