摘要：This study assessed the water quality at the outfall of six drains in River Ravi at Lahore, Bridge and BallokiBarrage and B-S Link canal to check suitability of water for propagation of fish and aquatic life. The waterquality parameters like pH, EC, DO, COD, BOD, TDS, SO 4 and heavy metals (Fe, Cu, Cr, Ni) were analysedat the outfall of six drains and three other locations on the river in 62 km stretch. The sampling periodincludes wet and dry weather seasons and canal closure periods. The study reach included the effect ofurban and industrial effluents from the six drains and dilution effect of flow augmentation through Q-B Linkcanal. The results showed that the river water quality was not suitable for aquatic life during dry weather andcanal closure period when compared with U.S.EPA standards for fish and aquatic life. The DO, BOD andheavy metals were not within the safe limits. Augmentation of about 600 m 3 sec -1 discharge through B-Q Linkhelps to improve the water quality of the Balloki Barrage pond. However, during canal closure period thesituation aggravates as this additional freshwater is not available during December and January. The riverwater quality at Lahore remained unsafe for aquatic life. The wet weather helps to flush out and slightlyimprove the water quality during July and August. Nevertheless, the storm water also brings heavy pollutantload from the city to the river. The study concluded that the disposal of untreated drainage effluent to the riverremains as a major threat to its water quality and consequently the aquatic life.
