台州市大陈岛海域水环境承载力研究

Water environment carrying capacity of Dachen Island sea area,Taizhou

本文于2019年11月对台州市大陈岛海域20个站位进行了海水水质调查,采用改进的内梅罗污染指数法计算重金属综合污染指数,然后应用主成分分析法对水质数据进行分析与筛选,最后应用BP神经网络进行水环境承载力计算与评价。研究结果表明:除了DIN、PO4-P之外,其余指标均满足二类海水标准;个别站位Pb含量略高,但重金属总体浓度满足二类海水标准;主成分分析显示海域水环境质量的主要驱动因子为DIN、PO4-P、CODMn、DO、重金属综合污染指数和石油烃;基于BP神经网络的水环境承载力指数具有空间异质性,呈现西北部海域较低,随离岛距离增加而向东南侧递增的特征,生态保护区水环境承载力为可承载,满足海洋牧场建设的水质要求,人为活动区为轻度超载,需加强水质的监测与管理。

Water quality at 20 sites in the sea area of Dachen Island,Taizhou City,was examined in Nov.,2019.The comprehensive pollution index of heavy metals was calculated with improved Nemerow index method,the water quality data were analyzed screened was with principla component analysis method,and the water environment carrying capacity was calculated and evaluated with BP neural network strategy.The results showed that all indexes meet the second grade of seawater quality standard except DIN and PO4-P;Pb content of individual sites is slightly higher than others,but the overall concentration of heavy metals meet the second grade;the main driving factors of water environment quality are DIN,PO4-P,CODMn,DO,comprehensive pollution index of heavy metals and petroleum hydrocarbons.The water environment carrying capacity revealed by BP neural network was spatially heterogeneous,being lower in the northwest sea area and increasing to the southeast with the increase of the distance from the island.The water environment carrying capacity of the ecological protection zone was capable,and the water quality met the requirements of marine ranching construction.While the human activity area was slightly overloaded,the monitoring and management of water quality should be strengthened.