Assessment of Spatio-Temporal Changes in Water Quality of Babolroud River Using IRWQIsc, NSFWQI and CCME Water Quality Index

Water, one of the most important elements in the world, is known to be essential for the survival of living organisms and the health of water resources, especially surface water, is a key factor in determining the health and sustainability of aquatic ecosystems. Rivers are among the most important sources of surface water that have been severely affected by pollution in recent years due to population growth, industrial and agricultural activities, and wastewater discharge. Water Quality Index (WQI) is a widely used tool for assessing the quality of river water and other water resources. In this study, water samples were taken from three stations along Babolroud River during one hydrological year (from September 2019 to August 2020) to evaluate its water quality, and the quality parameters were analyzed using three indices: Iran Surface Water Quality Index (IRWQIsc), National Sanitation Foundation Water Quality Index (NSFWQI), and Canadian Water Quality Index (CCMEWQI). The use of these three indices provides a comprehensive approach to water quality assessment and management, enabling us to better understand the health and sustainability of water resources. According to the results, the IRWQISC index ranges from 50 to 78.9, the NSFWQI index ranges from 57 to 73, and the CCME WQI index ranges from 31 to 38, indicating moderate to poor water quality in the river, especially downstream. The main factors contributing to the low quality of water are the entry of pollutants from residential and agricultural areas, uncontrolled human activities, and land use changes along the river.