杭州湾水体富营养化评价及分析

Analysis and assessment on eutrophication in Hangzhou Bay

根据2007年杭州湾4月和8月COD、无机氮（DIN）和磷酸盐（DIP）调查数据，并结合1987年以及2004～2006年的调查资料，对杭州湾水体富营养化进行了分析和评价。结果表明杭州湾海域处于严重的富营养化状态，富营养化状态指数中DIN占优势，其次为COD，这两者起到了绝对性作用。水体营养等级基本为P中等限制潜在性营养（Vp）。通过比较发现，1987年杭州湾已经处于严重富营养状态，枯水期和丰水期其平均富营养化指数分别为22．4和17．8，与2004～2007年相差不大。

Based on the investigation data of COD, inorganic nitrogen （DIN） and phosphorus （DIP） from two cruises in Apr. and Aug. of 2007 in the Hangzhou Bay, and combining with the data in 1987, and from 2004 to 2006, this paper dealt with the water eutrophication. The Hangzhou Bay was in the serious eutrophication condition, COD and DIN were the dominant compositions of eutrophication index. The level of potential eutrophication was Vp. The Hangzhou Bay was already in the serious eutrophication condition in 1987, and the eutrophication index of dry season and wet period was 22.4 and 17.8, respectively, which were almost same index from 2004 to 2007.