The relationship between the quality of underground water in Saveh Plain and the amount of rainfall in 2016-2018

Saveh plain, which is one of the semi-arid regions of the country.There is a demand for underground water resources due to extensive agriculture and also the existence of the country's largest industrial city, and the limitations of surface water resources are high. The purpose of this study is the impact of short-term rainfall on the amount of changes in the quality of underground water in this region.

Materials and Methods :

This is a cross-sectional descriptive study to evaluate the impact of rainfall on the chemical quality of water in the underground water resources of Saveh Plain in the period (2016-2018). Necessary information was collected from Iran's specialized mother company of water resources and the results were analyzed using DIC (Drought Indices Calculator) software and Chemistry software, and Wilcox and Shuler charts were used to determine drought years.

 The results showed that in the water year of 2016-2017, a severe drought prevailed in the Saveh Plain catchment area, but in 2017-2018, more rains occurred in this area, so it is considered a water year. The occurrence of successive droughts along with over-harvesting has caused the water in 74% of wells and 43% of aqueducts to be of unfavorable quality for agricultural purposes. For drinking purposes, the situation is better and 30% of wells, 53% of aqueducts and 93% of springs are in good and acceptable range for drinking purposes.

The results showed that the physical and chemical quality of underground water resources including wells, aqueducts and springs are affected by the amount of rainfall and the impact on underground water sources which are springs and aqueducts is more than short-term rainfall changes compared to wells in the region. Therefore, for optimal management, there is a need for proper planning in order to manage the consumption of water resources, change the pattern of cultivation and reduce unnecessary harvests in the mentioned plain.