Assessment of the Surface Water Quality of Kebir–Rhumel Catchment Area Through Physico–Chemical and Biological Analysis

The water quality status of the Kebir–Rhumel watershed was evaluated in terms of its physical, chemical, and biological parameters. Samples were collected monthly over a period of 2 years, from January 2016 to December 2017. Thirteen physicochemical parameters and macroinvertebrate fauna were recorded from 15 sites located along the catchment area in the two principal rivers: El Kebir and Rhumel. The standard global biological index (IBGN) was calculated from faunal data collected to establish the biological quality of the two wadis. The main component analysis showed that the stations of the Rhumel wadi located in the city center of Constantine are the most polluted, the NO₂^-, NO₃^-, PO₄⁻³, Ca²⁺, Mg²⁺ and SM contents are the consequences of human and industrial anthropogenic actions. The cluster analysis (CA) result indicates that the sampling sites are grouped into three distinct groups. According to the IBGN index, these stations range from average to poor quality during the entire study period and for the majority of the stations. The stations located on wadi El Kebir have a good to poor water quality except for station K10, which has poor to very poor water quality throughout the study period. Results indicated congruence between both approaches (physicochemical and IBGN index). The physicochemical and biological approaches remain useful for assessing the health of aquatic environments.