基于指标体系法的海湾生态系统健康评价方法——以莱州湾为例

Ecosystem Health Assessment for Bay Based on Index System in Laizhou Bay

海湾生态系统在维持能量流动、物质循环、生物群落稳定和生态系统平衡等方面发挥重要作用。文章基于2011-2020年夏季监测数据,选取水环境、沉积环境、生物群落、初级生产力和生态灾害5类指标,通过层次分析法与专家咨询法相结合的方式确定指标权重,基于指标体系法构建莱州湾生态系统健康评价指标体系。评价结果表明:莱州湾近岸海域生态系统长期处于亚健康状态,主要影响指标为水环境和生物群落;生态系统健康评价结果与现行《近岸海洋生态健康评价指南》基本一致,但本方法能够识别溢油和台风等极端事件对生态系统造成的不利影响,较传统方法更为灵敏;区间型指标和环境容许值的引入可避免监测数据“劣势掩盖”“信息漏缺”以及极限监测值对评价结果的放大问题。

The bay ecosystem plays an important role in maintaining energy flow, material circulation, community stability and ecosystem balance. In the present study, the comprehensive evaluation model for marine ecosystem of Laizhou Bay was established by using index system method, in which, five indicators were selected including water environment, sedimentary environment, marine community, primary productivity and ecological disaster indexes. The relative importance and weight of the evaluation indexes were determined combined using analytic hierarchy process and experts consultation method.By analyzing the survey data obtained, this assessment system was applied to assess and compare the health level of Laizhou Bay in recent ten years. Results showed that the condition of Laizhou Bay was always being sub-health, the main indicators that had given adverse impact on the health level of Laizhou Bay included inorganic nitrogen, phosphate, petroleum hydrocarbon, plankton species and benthic biomass. The results of evaluation model were more sensitive to Laizhou Bay, which could identify the adverse effects of extreme events such as oil spills and typhoons, therefore, the use of interval index and environmental admissible value could avoid disadvantage concealment, information omissions and the overestimation of limit value-based assessment method effectively.