The Relationship of Land Use and Quality of Groundwater Resources of Chaharmahal & Bakhtiari Province

Groundwater is the most important source of potable water in the most of the cities and villages of Iran. Nitrate and phosphate are the greatest current groundwater pollutants that threaten the health of the people in Iran. This research was done with the aim of assessing the effect of land use on the quality of potable water. To this aim, 132 water samples from 132 wells used for drinking purposes in different locations of the province were prepared, and nitrate and phosphate concentrations in samples were measured with a spectrophotometer. The results showed nitrate concentrations in 92.42% of the samples were below the permitted limit, while 7.58% of the samples were higher than standard. Phosphate concentration in 100% of the samples was lower than both the global and Iranian standards. Also, there was significant correlation between nitrate and phosphate concentrations (r = 0.29). According to the obtained results, nitrate concentrations in residential areas were significantly different from those in rangeland, forest and garden land uses (p <0.05). Phosphate concentration in residential areas, agriculture, rangeland and garden land had significant differences with those in forest land use (p <0.05). Now, water quality with regard to nitrate concentration in most parts of the province and phosphate concentration in all parts of province were in compliance with standards, but nitrate concentration was 10 points higher than the permitted level. Therefore, monitoring, purification, wastewater generation and lower consumption of nitrate fertilizer should be considered.