Development of a Water Quality Index for Lake Aygır in Bitlis, Turkey

Water quality indices help to develop correct policies using water quality data. In this study, a useful and reliable method was determined for water quality management of Lake Aygır. For this, monthly water quality measurements were made from Lake Aygır between May 2015 and May 2016. Expert opinions and literature were used in the selection of parameters. Temperature, dissolved oxygen, electrical conductivity, pH, ammonia, alkalinity, hardness, fluorine, and arsenic parameters were selected for the calculation of the water quality index of Lake Aygır for drinking (AG-WQIdrinking), as it is more effective on human health. Temperature, dissolved oxygen, electrical conductivity, pH, ammonia, alkalinity, hardness, and turbidity were selected for the calculation of the water quality index of Lake Aygır for fisheries (AG-WQIfisheries) as they are the parameters to which fish is most affected. Water quality indices of Lake Aygır were found AG-WQIdrinking as 149.41 and AG-WQIfisheries as 76.11. The most effective parameters were hardness and alkalinity in the AG-WQIdrinking calculations; and ammonia and dissolved oxygen in the AG-WQIfisheries calculations. Hence, it expresses numerically the suitability of Lake Aygır in terms of drinking and fishing.