Assessment of surface water quality of the Ceyhan River basin, Turkey.

In this study, surface water quality of the Ceyhan River basin were assessed and examined with 13 physico-chemical parameters in 31 stations in 3 months during the period of 2005. Multivariate statistical techniques were applied to identify characteristics of the water quality in the studied stations. Nutrients, Cl- and Na+ affected mostly to the stations of Erkenez 2, Sir 2, and Sir 3 in the ordination diagram of correspondence analysis. Three factors were extracted by principal component analysis, which explains 79.14% of the total variation. The first factor (PC1) captures variables of EC, DO, NO2-, PO4triple bond, Cl-, SO4=, Na+, and Ca++. The second factor (PC2) is significantly related to pH, NH3-, and Mg++, while water temperature (T) and NO3- accounted for the greatest loading for factor 3 (PC3). The stations were divided into three groups for PC1, two groups for PC2, and three groups for PC3 by hierarchical cluster analysis. The stations in the vicinity of cities presented low dissolved oxygen and high concentration of physico-chemical parameter levels. The stations of Erkenez 2, Sir 2, Sir 3, and Aksu 4 located near the city of Kahramanmaraş were characterized by an extremely high pollution due to discharge of wastewater from industry and domestic. Pinarbaşi and Elbistan stations were also influenced by household wastewater of the city of Elbistan. According to criteria of Turkish Water Pollution Control Regulation, Erkenez 2, Sir 2, and Sir 3 stations have high polluted water. This study suggests that it is urgent to control point pollutions, and all wastewater should be purified before discharge to the Ceyhan River basin.