【摘要】 基于1984—2015年监测数据,给出长江口及其邻近海域无机氮和活性磷酸盐长时间序列的变化趋势,确定了营养盐的基准年是1987年,基准值分别是0.0705 mg/L和0.000751 mg/L。结合频数分析方法,无机氮的分区阈值为0.339 mg/L和1.15 mg/L,活性磷酸盐的分区阈值为0.0289 mg/L和0.0530 mg/L,研究区域可划分为三大分区:口内区、过渡区和口外区;结合生态红线、污染源等具有开发管理属性的分布,最终将研究区域分为8个评价单元。提出了水质环境、沉积物环境、生物生态三类三级评价指标体系,建立了海洋生态环境综合评价方法。水质环境的区域分布与生物生态相似:口内区域较差,口外区域向海逐渐趋好;沉积物环境特征:南支、北支和北港的沉积物质量略好于口外区域,口外区域好于南北槽分区和杭州湾北部。生态环境综合状况由差向好的区域变化为:Ⅳ区<Ⅴ区<Ⅲ区<Ⅰ区<Ⅱ区<Ⅵ区<Ⅷ区<Ⅶ区;随时间有向好趋势。更多还原

【Abstract】 Based on monitoring data from 1984 to 2015, we report a trend analysis of dissolved inorganic nitrogen(DIN) and phosphate(PO4-P) in the Yangtze River Estuary and its adjacent area; the reference year of nutrients was determined to be 1987, and recommended reference values were 0.0705 and 0.000751 mg/L for DIN and PO4-P, respectively. Then, frequency analyses were combined to produce the partition thresholds of 0.339 and 1.15 mg/L for DIN, and those of 0.0289 and 0.0530 mg/L for PO4-P. Thus, the study area could be partitioned into three subareas: the inner area of the mouth, transition area, and outer area of the mouth. Considering the distributions of the ecological red line area and pollution sources, the study area was divided into eight comprehensive subzones. An integrated evaluation of the marine ecological environment was developed based on the index system method, which was composed of marine water, surface sediment, and biological diversity. The distribution of the marine water environment was similar to that of the biological and ecological characteristics; environmental indices improved from the inside to outside area. South Branch/North Branch/North Port was slightly better than the outside area where the sediment indices were higher than those of Hangzhou Bay/North Channel/South Channel. The distribution of the marine integrated environment was as follows: subzone IV < subzone V< subzone III < subzone I < subzone II < subzone VI < subzone VIII < subzone VII, which indicated that the integrated environment was obviously improving with time.更多还原