Temporal Changes in Water Quality Parameters of Two Sections of the Ancient Canal: A Case of a Reach for Yangnong Chemical Plant

Abstract

The water quality of the Ancient Canal has changed significantly due to the continuous urbanization of Yangzhou City. The main objective of this study was to reveal the temporal changes of conventional water quality parameters in a specific section of the Ancient Canal that flows through the Yangnong Chemical Plant. Two sections (Sec. 1 and Sec. 2) located upstream and downstream of this chemical plant, respectively, were chosen for observation of water quality parameters, including temperature (WT), pH, dissolved oxygen concentration (DO), electrical conductivity (EC) and total dissolved solids (TDS) content. The correlation coefficient method (CC), single factor index method (SFI) and variation coefficient method (VC) were used to analyze the data obtained from October 2015 to September 2016. The results indicated that (1) WT of Sec. 2 was higher than Sec.1 by an average of 0.8°C. In addition, the pH increased and decreased occasionally and with no obvious trend. The mean DO of Sec. 2 was 1.80 mg/L lower than that of Sec. 1. The EC and TDS of Sec. 2 were higher than those of Sec. 1; a relatively high correlation existed between the observed results of each corresponding parameter between Sec. 1 and Sec. 2. Overall, the water quality of Sec. 2 was worse than that of Sec. 1 over the study period; VC of the DO was the maximum, while the VC of the pH was the minimum. The results provide a partial basis for further studies on water quality of the Ancient Canal and urban river of Yangzhou City.