基于PSR的黄河河口区生态系统健康评价

根据压力-状态-响应(PSR)框架模型,从广义上定义河口区生态系统,将河口及毗邻的陆域、海域生态系统作为一个整体,从压力指标、状态指标、响应指标3个方面构建了黄河河口区生态系统健康评价的指标体系,以研究区1991年数据和相关国家标准为基准,2013年代表现况,利用综合指数法(CEI)评价了黄河河口区的生态系统健康状况。结果显示:黄河河口区生态系统健康评价的响应指数最高(0.9055),压力指数居中(0.8288),状态指数最低(0.6458),综合指数为0.7427。总体来看,与1991年相比,目前黄河河口区生态系统仍处于"健康"状态,但健康状况明显下降,其中状态指数下降最为严重。从区域轻度开发到人类活动强烈干扰阶段,黄河河口区存在过度捕捞、湿地不合理开发、浅海养殖过度及污染物排放等一系列影响生态系统健康的问题,应进行区域的生态恢复和科学管理。

Assessment of the ecosystem health of the Yellow River Estuary based on the pressure-state-response model

As the main channel of matter exchange between riverine and marine environments, estuarine ecosystems have been subjected to growing environmental interference and disturbance. Anthropogenic activities and the interactions between land and sea considerably affect estuarine ecosystems and health, and they have resulted in challenges for ecosystem management. Ecosystem health assessment, a new method of ecosystem assessment, determines the current ecosystem structure and function, and provides substantial information necessary for effective ecosystem management. Therefore, for the management of the Yellow River Estuary, a pressure-state-response (PSR) method was used to assess the health status of the ecosystem. The estuary and the adjacent marine and terrestrial ecosystems were considered an entity under the broad definition of estuarine ecosystems. An ecosystem health assessment indicator system was developed, taking external pressure, ecosystem state, and response parameters into consideration to calculate indicators of regional ecosystem health. The health status of the Yellow River estuarine ecosystem was then assessed using a comprehensive evaluation index (CEI), including historical data from 1991. The results showed that the overall index of the Yellow River Estuary was 0.7427 in October 2013. In detail, the response index was 0.9055, which indicates that the Yellow River estuarine ecosystem was "very healthy," suggesting the policy and behavior of local government, relevant departments, and individuals reduced the pressure on the regional environment to a certain extent. The pressure index was 0.8288, which indicates that the ecosystem was at a "good status," but has been under growing pressure and its health has deteriorated. The state index was 0.6458, suggesting that the ecosystem is "unhealthy" and is under considerable pressure, requiring improvement. Overall, the current status of the Yellow River estuarine ecosystem was reasonably "healthy" as compared to that in 1991, but it has deteriorated. The state index showed the most serious decline among pressure, state, and response indexes. The main reasons for the health degradation of the Yellow River estuarine ecosystem were investigated by analyzing the index variation and its weight. The factors resulting in the deterioration included overfishing, unreasonable wetland development, over-farming in shallow seawater, and pollution. Therefore, actions should be taken to prevent further deterioration through ecological restoration and appropriate management of the Yellow River estuarine ecosystem. Any future development should be based on scientific planning for the sustainability of the ecosystem.