The results indicated that the water quality in main river was better than tributaries,downstream was better than upstream and suburbh an river was better than urban river.

• 结果表明主干流的水质逐渐得到改善,但不同河段的水质变化较大。主干流水质好于支流、下游水质好于上游、远离城市河段好于市区河段。