河口与近海营养状况评价方法及其应用验证

基于压力-状态-响应(PSR)模型,建立了我国河口与近海营养状况评价法. 通过分析当前富营养化概念模型研究结果,引入A(人为影响指数)和表征过滤与调节作用的ΔSA/SA(层化系数)作为压力指标,从富营养化负面效应筛选出高效的表层ρ(Chla)、d(浮游植物细胞密度)、底层ρ(DO)、a(底栖生物个体丰度)和RT(赤潮指数)作为状态指标,并以v(未来营养盐通量年均变化)作为响应指标. 综合考虑国内外相关标准来界定评价指标分类标准,采用统计处理、矩阵法集成得到G(营养状况等级),并成功应用于九龙江河口区. 应用验证结果表明:2010年九龙江河口区G为“差”,北部采样点优于南部,与人为环境压力空间分布一致；Kolmogorov-Smirnov非参数检验显示,G为“中”和“差”的两类采样点之间的ρ(COD)、ρ(DIN)、ρ(TN)、ρ(DSi)、ρ(SPM)(其中DSi和SPM分别为溶解态硅酸盐、悬浮颗粒物)差异显著(p<0.05),ρ(TP)、ρ(DIP)因“磷缓冲”机制而趋于均匀分布(p>0.05),评价结果可识别出评价体系并未包含的主要环境因子状况；与第一阶段评价法相比,河口与近海营养状况评价法注重富营养化症状的评价,因此具有更易识别营养状况恶化与否的优势. 

Application and Validation of an Integrated Methodology for the Assessment of Estuarine and Coastal Trophic Status in China

Abstract:An integrated methodology based on the Pressure-State-Response framework was developed to assess the estuarine and coastal trophic status in China. The contemporary conceptual model of coastal eutrophication was analyzed, and the index of anthropogenic influence (A) and the stratification parameter (ΔSA/SA) characterizing the filter role of estuarine and coastal systems were introduced to Pressure. For State, high performance indicators including surface concentration of chlorophyll a (ρ(Chla)), phytoplankton cell density (d), bottom water dissolved oxygen concentration (ρ(DO)), benthic organism individual abundance (a), and red tide index (RT) were screened from the negative effects of eutrophication. For Response, annual rate of change of nutrient flux in the future (v) was selected. The levels of the indicators were applied after consideration of domestic and overseas standards, and the PSR components were aggregated to produce an overall grade. The results of application and validation of the methodology in the Jiulongjiang Estuary showed that the overall grade was poor in 2010, though the grades were better in the north than in the south of the estuary. This result accurately reflected the anthropogenic pressure. Comparison of the environmental factors using the Kolmogorov-Smirnov test showed significant differences (p<0.05) between the two grades for ρ(COD), ρ(DIN), ρ(TN), ρ(DSi) and ρ(SPM), identifying the main environmental factors other than the selected indicators. The difference between two grades for ρ(TP) and ρ(DIP) was not significant (p>0.05) as a result of the phosphate buffer mechanism. Compared with Phase Ⅰ, the new method emphasizes the evaluation of symptoms and has the advantage of clearly identifying whether or not trophic status has deteriorated.