Assessment of water quality in drainage canals of Çarşamba Plain, Turkey, through water quality indexes and graphical methods

In this study, the seasonal variation on drainage water quality of Çarşamba Plain, Turkey has been evaluated from June 2012 to January 2013 and determined the suitability of water for irrigation purpose. Water samples collected from 21 drainage canals during July and January were analysed for 12 water quality parameters including physico-chemical analyses. Piper diagram and United States Salinity Laboratory (USSL) diagram were prepared to investigate water quality. Sodium Adsorption Ratio (SAR), Percent Sodium (Na%), Residual Sodium Carbonate (RSC), Kelly Index (KI), Magnesium Ratio (MR), Langelier Saturation Index (LSI), Permeability Index (PI) and Potential Salinity (PS) were also used to assess suitability of waters for irrigation.

In July 2012, EC values varied between 0.45-4.23 dS/m. Waters of 7 drainage canals were found to be unsuitable for irrigation with regard to KI, 3 canals with regard to RSC and 13 canals with regard to MR. According to USSL diagram, 24% of drainage waters were classified in C₂S₁, 62% in C₃S₁, 4% in C₄S₂ and 10% in C₄S₄ class. In January 2013, EC values varied between 0.16-1.44 dS/m. Waters of one canal was found to be unsuitable for irrigation with regard to KI and 8 canals with regard to MR values.