Assessment of Water Quality Indices Using Physico-chemical Parameters in Zayande Rood Dam Lake

Background: Biological and ecological studies of water resources play the primary role in the researches. The Zayande-rood’s dam lake is one of the vital water resources that provide drinking water for the populations in Isfahan. It is also a water resource for agricultural sections of the province. Methods: Five spots were defined as the sampling stations. Sampling was conducted in seven steps, with one sampling event every 45 days. The water quality parameters including dissolved oxygen (DO), nitrate, nitrite, electrical conductivity (EC), pH, hardness, total dissolved solids (TDS), ammonium, and biochemical oxygen demand (BOD) were measured in all the stations and stages. Next, the water quality indices were calculated. Results: The study’s results illustrated that the water quality, with an average score of 74.41 on the water quality index (WQI), fell within the ‘well’ class, indicating its suitability for human consumption and drinking purposes. Station 4 scored the highest NSFWQIa (74.93), while station 3 had the lowest (70.57). According to the NSFWQI classification, all stations are categorized as ‘good’ in terms of water quality. The NSFWQIm ranged from 50.94 to 59.04, showing moderate changes in water quality. Both the NSFWQIa and NSFWQIm classify it as ‘moderate’ or ‘midclass’ quality. Conclusion: Considering the significance of Zayande-rood’s dam lake as a crucial source of drinkable water for Isfahan, it becomes evident that there is a pressing need for significant attention to be directed toward lake watershed management to protect water quality.