Comparative survey on Physico-Chemical parameters of underground waters in Malard county villages with the use of GWQI index and studying the trend of their changes in GIS system

Factors such as atmospheric precipitation reduction, inefficient agricultural methods, the threat of water resources from pollutants, etc. have all resulted in water supply issue confronting two challenges of quality and quantity in relation with aquifers. Similarly, in Malard county, underground water aquifers are the primary source of water supply. The information of physiochemical parameters of water samples of 9 water wells in Malard County during two drought and wet periods in the year 1396 have been collected. The objective of this study is the qualitative modeling of underground water and the calculation of GWQI index in the GIS system, and comparison. The findings showed that the quality of underground water from east to west, and from northeast to southwest confronts increment in physicochemical parameters because of the situation of the wells' depth, underground water scarcity, the decrease of earth self-purification, and bedrock lift as geological and hydrological factors as well as human factors entering the aquifers. This issue is more serious in Dehak Qeshlaq and Sharifabad counties. Considering the appropriate self-purification condition in Khoshnam County, this area can be introduced as a safe region. Moreover, a meaningful relation has been obtained between the outcomes resulted from GIS and GWQI.