Evaluation of Water Quality Monitoring Networks Using Principal Component Analysis: A case of Gediz River Basin

Abstract

The water quality needs to be monitored at regular intervals, throughout representatively located gauging stations, for sustainable development of water resources. However, it is not possible to monitor all quality parameters all the time and points for a river basin studied, and water quality monitoring that does not address specific, clear and realistic objectives will cause time, labor and money losses. At this point, Principal Component Analysis (PCA) would provide a regional insight into principal pollutants, contaminants dominates others and effective monitoring locations. It will help to evaluate surface water quality in regional scale as well as monitoring network. This study aims to analyze regional water quality and monitoring network in the Gediz River Basin, by focusing on the variance structure of the observations on principal pollutants that observed throughout the river basin. The 11 quality parameters monitored in 13 monitoring stations on the Gediz River Basin were used in the analyses. PCA is applied i) to determine principal pollutants and contaminants dominate over others (parameter-based analysis), ii) to find out effective monitoring locations for principal pollutants (station based analysis). The results reveal the tributaries of the river with different quality characteristics, and the importance of an objective based monitoring for effective water quality management.