生态修复工程对天津清净湖生态服务价值影响评估

Impact Assessment of the Ecological Restoration Project on Qingjing Lake in Tianjin

以天津中新生态城污水库为研究对象,通过市场价值法、替代工程法、碳税法和工业制氧法等研究方法建立生态服务价值评价指标体系,定量评估产品服务、调节服务、支持服务和文化服务的生态价值,分析生态修复工程实施前(2009年)后(2017年)清净湖的生态服务价值变化,评估修复工程投入与工程实施后的生态效益。结果表明,污水库生态服务价值估算为2 546.76万元/a,其中调节服务是主要生态服务类型,占总价值量的99.46%;生态修复工程(总投资1.5亿元)实施后,清净湖生态服务价值估算为15 099.54万元/a,文化服务成为其主要服务类型,占总价值量的87.93%。对比分析发现,生态修复工程带来的生态效益明显增加,生态服务总价值量增加了5.9倍;其中生物多样性、游憩和景观美学等服务增值明显,均由0分别增加至12.20万元/a、21.02万元/a和13 255.28万元/a。通过探究清净湖生态修复工程对污染生态系统服务价值的影响,可为类似城市水体开展生态修复项目决策提供科学依据和借鉴参考。

At present, quite a few large-scale water environment treatment projects are being implemented in China, but there is no standardized accounting method for calculating the return on the large capital investment. Determining the value of ecosystem services is an effective means of evaluating the cost efficiency of ecological restoration projects. It is widely used and provides a rational,scientific methodology for decision-makers. In this study, a wastewater reservoir, located in Sino-Singapore Tianjin Eco-City was selected for a case study on an ecological restoration project initiated in 2009 to convert a wastewater reservoir to Qingjing Lake. We compared the ecological service value before(in 2009) and after(in 2017) the conversion. The ecological benefits of the project were determined based on an established index system for evaluating ecological services that includes eight indices of four functions: product services, regulation services, support services and cultural services. The economic value of the ecological services provided by the waste-water reservoir was estimated at 25.467 million CNY per year, and the primary service was regulation of water quality, accounting for 99.46% of the total value. After completing the 150 million CNY ecological restoration project, the economic value of the ecological services provided by Qingjing Lake was estimated to be 150.9954 million CNY per year. Provision of cultural services was the primary service function, accounting for 87.93% of the total value. The ecological restoration project significantly increased the value of ecological services, and the total economic value of Qingjing Lake is 5.9 times the value of the original wastewater reservoir, with the service values of biodiversity, recreation and landscape aesthetics increasing from no value to respective values of 122 thousand CNY, 210.2 thousand CNY and132.5528 million CNY per year. The return on investment(ROI) was exceptional and the total cost of the ecological restoration project was nearly recovered in the first year after completion. Our case study of Qingjing Lake shows that urban ecological restoration projects are potentially very cost effective and the results provide a scientific basis and reference for decision-making involving similar ecological restoration projects.