县域汛期污染研究

Research on county flood season pollution

笔者在2022年选择位于长江中下游平原河网区(浙江省绍兴市柯桥区)的12次独立降水,利用水质自动监测站等技术手段,研究31个地表水监测点位水质变化。汛期柯桥区污染物总体呈上升趋势,其中高锰酸盐指数、氨氮、总磷平均浓度分别上升到0.27、0.120和0.015 mg/L,差异显著(p<0.0001)。从影响因素看,汛期随着降水量的增加,水质污染程度随之增加。经配对Wilcoxon检验,小雨期间氨氮、总磷变化不显著(p>0.05),其余情形下,3项污染指标变化均显著。为进一步改善水质,笔者针对上述区域的不同特点给出了开展针对性的治水措施建议。

12 independent precipitation events in 2022 located in the river network area of the Middle and Lower Yan gtze Valley Plain Plain(Keqiao District,Shaoxing City,Zhejiang Province)were selected to study the water quality var iations at 31 surface water monitoring sites by using technical means such as automatic water quality monitoring statio ns.During the flood season,the overall pollution levels in Keqiao District are showing an upward trend.Specifically,t he average concentrations of permanganate index,ammonia nitrogen,and total phosphorus have increased to 0.27 mg/L,0.120 mg/L,and 0.015 mg/L,respectively.These differences are statistically significant(p<0.0001).From the perspe ctive of influencing factors,the pollution level increased with the increase in precipitation.According to the paired Wilc oxon test,there was no significant change in ammonia nitrogen and total phosphorus during light rain periods(p>0.05),but significant changes were observed in all three pollution indicators in other circumstances.In order to further improv e the water quality,targeted water control measures and suggestions are given according to the different characteristics o f the above areas.