Trend Analyzing of Chemical Water Quality Parameters (Case Study: Rudan River,Bernetin Station—Code 27013)

River water quality evaluation is one of the first and perhaps most important steps in river water quality management, because it makes the analyst’s vision clear about trends and how pollution changes relative to time, place, and circumstances. The purpose of this research is to evaluate the water quality and the process of changes in the water quality parameters of this river by graphic methods such as Wilcox, Schuler and Piper diagrams. These charts were used to monitor water quality and evaluate the data obtained from Berthaen Station from 1976 to 2007. In this study, Piper introduced water qualitative type of chlorine and water façade from saddle type. Based on the Schuler diagram, all water samples of the river Rudan are in a moderate and acceptable category for drinking and there is no barrier to drinking. The Wilcox chart also shows that most of the specimens are highly salty and suitable for farming (C3S1, C3S2) and in some water are poor, highly unsuitable water areas (C₄S₂). The results of water quality parameters analysis using non-parametric Mann-Kendall test showed that the parameters of acidity, carbonate, soluble salts, total cations, sodium, magnesium and chloride adsorption percentages, and other parameters were not trendy at the surface The confidence is 95%. The upward trend in water soluble solute changes indicates a decrease in water quality and an increase in soluble salts of this river.