Water quality characteristics of Chashma Jhelum link canal different flow conditions during 1997 to 2001

One thousand eighty five (1085) water samples from same point of Chashma Jhelum Link Canal flow conditions during January 1997 to November 2001 were collected. These samples were analyzed for physico-chemical constituents i.e. pH, conductivity (EC) micro S/cm, TDS, sodium, potassium, calcium, magnesium, chloride, and bicarbonates. Corrosion and scaling behavior studies were also carried out of some corrosion indices. Langelier Saturation Index has been found to be useful qualitative relative corrosiveness of water samples. The free energy change, which is the quantitative measure of the energy available to derive the precipitating reaction of calcium carbonate on metal surface, has also been calculated from Langelier Saturation Index (L.S.I.). The values of delta G of these water samples range from-0.03 to -0.44 Kcal/mol. during canal flow 0 to 4000 cusecs, while above this flow it ranges from 0.01 to 0.05 kcal./mol. Water samples having positive delta G values shows that corrosion is expected. Larson Ratio (L.R.) relative behavior of chloride (corrosive ion) and bicarbonate (protective ion). Aggressive action of water samples of C. J. Canal during January 97 to November 2001 has also been evaluated with the help of .L.R. of these water samples have values, between 0.17 to 0.89. The lower values of L.R. have been observed during high flow conditions. Langelier Saturation index (L.S.I.) of water samples of this canal 4000 cusecs have values between 0.325 to 0.020. It means that water samples in low flow condition were moderate scale forming in nature, while in high flow condition were moderate corrosive in nature having negative values. Different compositional groups of water have also been identified. The data shows that under maximum flow condition water is of calcium bicarbonate type, while in minimum flow condition it is of sodium type. It is evident that soil composition of C. J. Canal is of Ca-Na-HCO/sub 3/-CI type, so in high flow condition compositional group of water of this canal is Ca-Na-HCO/sub 3/-Cl type due to soil erosion, but under minimum flow condition water is of Na-Cl-HCO/sub 3/ type. The main reason of this type is seepage flow of salt range. (author)