环渤海主要城市近岸海域水质状况综合评价

Water Quality Assessment of Nearshore Waters of the Primary Urban Areas Around Bohai Sea

为评价环渤海13个城市近岸海域水质状况,基于渤海195个监测站位2020年3月和5月的实测水质数据,选取化学需氧量、无机氮、总氮、活性磷酸盐、总磷和石油类物质作为评价因子,采用雷达图指数、内梅罗指数和主成分指数对环渤海主要城市近岸海域水质状况进行了综合评价和等级划分。结果显示,渤海近岸海域主要污染物为无机氮和总磷,其次为石油类物质;葫芦岛、秦皇岛、大连和烟台的近岸海域水质状况较好,而位于辽东湾北岸辽河口附近的盘锦、锦州、营口以及位于莱州湾西侧的滨州近岸海域水质状况较差;3类水质综合指数对海水中盐度和悬浮物浓度敏感性较强,且相互之间及其与水质优良面积比例存在显著相关性,表明所选择的3类水质指数能够真实反映渤海近岸海域水质状况。研究结果可为渤海水质评价与综合治理成效评估提供借鉴。

Based on the water quality assessment of nearshore waters for 13 cities around Bohai Sea,we conducted a comprehensive water environmental evaluation using radar charts,Nemerow index and principal component index.Based on the evaluation results,the status of nearshore coastal water quality was clarified and the sensitivity of the three evaluation indices to assessment parameters was analyzed.The aim was to apply comprehensive water quality indices to marine environmental assessment,and provide a reference for effectively assessing the comprehensive treatment and ecological conservation of Bohai Sea.The radar chart was created and the Nemerow and principal component indices were calculated based on six seawater quality variables obtained at 195 sampling sites in the nearshore area of Bohai Sea in March and May of 2020.The variables included chemical oxygen demand(COD),inorganic nitrogen(TIN),total nitrogen(TN),soluble reactive phosphate(SRP),total phosphorus(TP)and oil.Results show that the primary pollutants in the nearshore water of Bohai Sea were inorganic nitrogen and total phosphorus,followed by oil.Water quality in the nearshore areas of Huludao,Qinhuangdao,Dalian,and Yantai was significantly good,while water quality in the nearshore areas of Panjin,Jinzhou and Yingkou,located in northern Liaodong Bay,and Binzhou city in western Laizhou Bay were significantly poor.The three seawater quality indices used in this study were all sensitive to the salinity and suspended matter concentration of the water and correlated significantly with each other.Regression analysis also shows a close relationship between the three water quality indices and good water quality ratios in nearshore areas,indicating that the radar chart and both indices accurately reflect the water quality status of the nearshore water of Bohai Sea.Thus,these methods are appropriate for rapid seawater quality assessment in the nearshore area of Bohai Sea,and for quickly comparing the water quality of different urban nearshore areas.