广西近岸海域不同海区水质评价及其动态

Evaluation of Seawater Quality and Its Dynamic for Different Inshore Areas in Guangxi Province

采用单因子污染指数法,评价广西近岸海域不同海区的水质状况,并分析其动态变化特征。结果表明:2016年各海区大多数站点的水质状况良好,少数站点水质受到污染,超标污染物主要为pH、溶解氧、活性磷酸盐和无机氮。2016年钦州海区水质状况较差,活性磷酸盐和无机氮污染指数p>1,最高值发生在丰水期和平水期;pH和溶解氧污染指数最高值发生在平水期。防城港和北海海区水质状况较好,总体未受污染。1990—1998、2014、2016年3个时段动态比较表明,钦州海区化学需氧量、无机氮污染指数呈上升趋势,石油类有所降低;防城港海区化学需氧量污染指数逐年上升,无机氮和石油类呈下降趋势;北海海区无机氮和石油类污染指数呈下降趋势,化学需氧量则表现为先减后增的趋势。

The inshore areas are the main area of human economic activities,where the quality of seawater has great impact on the development of economy and the ecological environment. The assessment of the sea＇water quality in different inshore areas in Guangxi ＇was quantified using pollution index of single factor,and its dynamic characteristics ＇were also analyzed in this paper. The results showed that： Water quality of most of the monitoring points was good, except a few of sites being polluted. PH, active phosphate and inorganic nitrogen wTere among the main pollutants.The quality of sea＇water of Qinzhou ＇was relatively poor,＇with the pollution index of active phosphate and inorganic nitrogen higher than one, and the highest pollution index of those indices occurred both in the period of the abundant ＇water and the flat ＇water; and the highest pollution index of pH and dissolved oxygen in Qinzhou sea area occurred in the flat ＇water period. The sea＇water quality of Fangchenggang and Beihai ＇was better than that of Qinzhou,indicating that the sea＇water hasn＇t been polluted.The pollution index of the chemical oxygen demand （COD） and the inorganic nitrogen in Qinzhou showed an upward trend,＇while the oils sho＇wed the opposite trend. The pollution index of COD in Fangchenggang sea area increased year by year,wThile the inorganic nitrogen and oils decreased over time; the pollution index of inorganic nitrogen and oil in Beihai sea area decreased over time,＇while the COD decreased first and then increased during the studied period.