IRRIGATION WATER QUALITY ASSESSMENT OF UPPER GANGA CANAL IN ROORKEE

Abstract

Water pollution has become a global challenge calling for attention. The Upper Ganga Canal (UGC) System which ays a nificant role in Northern India, as a source of water for irrigation, navigation and for spiritua' upiiftment is not spared. The main objective of this investigation was to assess the p011utoii status of UGC using Water Quality Index (WQI). In this study. forty (40) water samples were investigated for twenty (20) physico-chemical (p1-I, EC, TDS, Ca 4, Na', K', TH, TSS, TS, HCO3, CO3, NO3, PO4, Cl, SAR, %Na, RSC, P1) and twenty (20) trace metals (Ag, Al, As, Be, Li, Ca, Co, Cr, Cd, Cu, Cs, Fe, Hg, Pb, Ni, Rb, Mg, Se, V, Zn); and the results were integrated for calculation of the WQI of the UGC water for irrigation purposes. The pH values range from 7.3 to 8.2 with a mean value of 7.75 in monsoon season, and 6.5 to 8.02 with a mean value of 7.26 in winter season. The lowest and highest EC values of 168.4 jtS/cm and 746 jiS/cm respectively were observed. SAR mean value of 1.45 and 0.53 were recorded during monsoon and winter seasons respectively. The lowest and - highest recorded P1 values were 64 and 3 10 respectively. The results revealed that %Na has a mean value of 30.5 in rainy season compared to a mean of 28.5 in winter. Out of the 40 samples collected and analysed for RSC in both seasons. 80% shows excellent, 15% reveals good and % depict. medium RSC Fazard at the downstream of the canal in rainy season, whiles 90% of the sample analysed an be cicscribeJ as excellent and 10% lie within the good class in winter season. The calculated \s?QJ varies from 37 to 42 in monsoon and winter seasons respectively. with an ovet all WQI of 38.22. The VOI escalates considerably in space and time from the upstream tc do vnstream which may be de to an influx of pollutants from anthropogenic activities. The correlation analysis between the studied parameters show that these parameters %eve the same input source; akin geochemical composition and behaviour. The estimated WQI of this study suggests that, the canal water quality is good for irrigation purposes in both seasons. Conversely, water quality at the downstream (Gadarjudda minor) can best be used on soils with good structure, high permeability and on crops less sensitive to salinity. The study suggested that the WQI is useful in assessing the overall pollution status; and effective in the pollution zontion of the Upper G'nga Canal. The study also suggests the continuous monitoring of water quality at the downst1m; canal lining and vegetation removal from minor canals. Protection of water from pollution by diverting household effluents at the downstream is highly recommended.