Water quality evaluation of a lacustrine water body in the Mediterranean based on different water quality index (WQI) methodologies

The relative response of seven different Water Quality Indices (WQIs) was comparatively tested in an artificial Mediterranean lake, with the ultimate goal of the study to function as a first step in investigating the applicability of the examined WQIs in Mediterranean lacustrine water bodies. The following WQIs were examined: Prati's Index of Pollution, Bhargava's Index, Oregon WQI, Dinius' Second Index, Weighted Arithmetic Index, Canadian Council of Ministers of the Environment (CCME) WQI and National Sanitation Foundation (NSF) WQI, using physicochemical parameters measured in an artificial lake on a monthly basis from June 2004 to May 2005. The results showed that, on the basis of their comparative response, the examined indices are grouped in three categories. Specifically, NSF and Bhargava indices classified the examined water body in higher quality classes, Prati's and Dinius in medium, whereas CCME and Oregon categorized it in lower quality classes. WQIs were proved to be extremely useful in water quality evaluation. Most of them were found to be adequate to represent water quality conditions and trends in a lacustrine water body in the Mediterranean and, therefore, they present high potential to be adopted at European Union level and assist in Water Framework Directive (WFD) implementation.