基于水动力数值模型的港口规划累积影响评价

A case study of cumulative effects assessment for harbor planning in China

累积影响评价是战略环境评价的主要方法和重要内容之一,但目前还缺乏通用的评价程序和方法。通过识别港口规划的累积影响源和途径,建立了基于水动力数值模型的累积影响评价的量化评估和分析框架。以厦门港嵩屿港区规划为例,通过对海湾纳潮量及各敏感点流速的模拟,计算淤积量及其分布变化,进而推测海域水质和底质变化,并分析了由此引起的海洋生物群落的变化趋势。通过比较不同岸线方案的累积影响,为港区岸线优选提供了科学判据。实践表明,该方法框架综合运用定量预测和定性分析手段,其结果能为港口规划的战略环境评价提供科学依据。

Cumulative effects assessment （CES） has become an important approach and also a key component of the strategic environmental assessment due to the increased recognition that most significant environmental changes are results of combined effects of many individual impact factors. Analyzing combined environmental effects is simple in principle but difficult in practice due to a lack of simple and effective CES methods and procedures. The paper presents a case of CIE for the harbor planning project for Songyu Port in Xiamen, China. Major sources and pathways of the environmental impact factors were first identified and evaluated, and, using a custom hydrodynamic model, numerical simulations were then performed to quantify their cumulative effects on changes of tidal prism and flow velocities at select locations, siltation, water quality parameters （COD, N ＆P concentrations）, and the ecosystem in the area of interest. The cumulative effects were estimated for harbor planning alternatives for selection of the best. The results of CES for the Xiamen project have demonstrated its benefits in providing essential information for the strategic environmental assessment as well as a scientific basis for selection of the best alternative for a harbor planning project.