【摘要】 利用三峡库区长江干流1998年-2010年水质监测数据,以1998年-2003年代表蓄水前,2004年-2010年代表蓄水后,对比分析蓄水前后主要污染物浓度变化情况,用Spearman秩相关系数法判断其变化趋势的显著性。分析可知,蓄水后氨氮、化学需氧量、总磷指标的平均浓度要低于蓄水前,氨氮、化学需氧量浓度变化幅度大于蓄水前,总磷浓度变化幅度小于蓄水前;Spearman秩相关系数计算结果表明,三峡水库常年回水区内的断面,污染物浓度多数呈下降趋势,但只有晒网坝和培石断面的氨氮指标浓度下降趋势具有显著意义。更多还原

【Abstract】 The 1998-2010 water quality monitoring data in mainstream of Changjiang River in Three Gorges Dam watershed were separated into a pre-storage period( 1998-2003) and a post-storage period( 2004-2010). The concentration changes of major pollutants before and after storage were analyzed. The significance of changing trends was tested by Spearman rank correlation coefficient. The results show that compared with the pre-storage period,the average concentrations of ammonia nitrogen( NH3-N),chemical oxygen demand( COD),and total phosphorus( TP) were all lower after storage. The changing amplitudes of NH3-N and COD were larger and the changing amplitude of TP was smaller compared with the pre-storage period. Spearman rank correlation analysis shows that in the sections in perennial backwater zone,concentrations of most pollutants decreased,but not significantly except NH3-N in Shaiwang Dam and Peishi sections.更多还原