基于季节性Kendall检验和重标极差分析法的阳澄湖水质变化趋势分析

为掌握《苏州市阳澄湖生态优化行动实施方案》实施以来阳澄湖的水质变化趋势,结合季节性Kendall检验与重标极差分析(R/S)法,对2013-2018年阳澄湖及其6条主要入湖河道的主要水质指标--高锰酸盐指数(IMn)、氨氮(AN)、总磷(TP)、总氮(TN)过去和未来的水质变化趋势进行分析及预测。研究结果表明:(1)阳澄湖除TP无显著升降趋势外,其余指标均有不同程度的下降趋势;(2)主要入湖河道的TN均无显著升降趋势,其余指标的改善效果较明显;(3)未来阳澄湖及主要入湖河道水质总体将会持续改善,但有个别监测点位的TP浓度未来仍有可能会上升。可见,近年来阳澄湖生态优化行动卓有成效,但TP已成为影响水质达标的最大制约因素,还需进一步提出针对性治理措施。

Analysis of water quality change trend of Yangcheng Lake based on seasonal Kendall test and rescaled range analysis

In order to grasp the water quality change trend of Yangcheng Lake since the implementation of the"Ecological optimization action plan of Yangcheng Lake in Suzhou City",the seasonal Kendall test and the rescaled range analysis(R/S)method were used to analyze and predict the past and future water quality trend of the main water quality indexes of Yangcheng Lake and its six main inflow river channels from 2013 to 2018,including permanganate index(IMn),ammonia nitrogen(AN),total phosphorus(TP)and total nitrogen(TN).The results showed that:(1)TP had no obvious change trend,but other indexes had different degrees of downward trend.(2)There was no obvious change trend of TN in the main inflow river channels,and the improvement effect of other indicators was obvious.(3)In the future,the water quality of Yangcheng Lake and its main inflow river channels would continue to improve,but the TP concentration at some monitoring points might still rise in the future.It showed that the ecological optimization action of Yangcheng Lake had been effective in recent years,but TP had become the most restrictive factors affecting the water quality,and targeted measures needed to be put forward.