海平面上升背景下环渤海海岸敏感性研究

Sensitivity Analysis Along the Bohai Coast Under the Background of Sea Level Rise

在全球气候变化、海平面上升背景下,全球许多海岸已经成为承受巨大压力的生态系统。应用海岸敏感性指数(Coastal Sensitivity Index,CSI)对中国环渤海海岸进行敏感性分析,采用岩性、海岸坡度、地貌、岸线变化速率、相对海平面上升水平、平均波高以及平均潮差多种变量的不同组合计算环渤海海岸479个单元格的敏感性数值。结果表明,增加变量数目或以岩性代替岸线变化能有效提高敏感性指数的区分能力,但不同组合下环渤海海岸敏感性宏观空间格局无较大差异。总体上,胶辽隆起带与大兴安岭-太行隆起带的山地丘陵基岩海岸敏感性相对较低,而以辽东湾辽河口附近沿岸平原海岸和渤海湾-黄河三角洲-莱州湾南岸平原海岸为代表的渤海、华北沉降带表现的敏感性相对较高。研究结果有助于海岸管理与规划人员在全球变化背景下识别海岸敏感区域,从而有选择性地采取应对措施缓解海岸带压力,并且为开展河口海岸生态系统脆弱性研究奠定科学基础。从长远来看,海岸敏感性分析如果与社会因子相结合更能有效提升海岸带系统整体的脆弱性研究水平。

Under global climate change and sea level rise, many coastal areas have become ecosystems with- standing great pressure around the world. This article presents an analysis of sensitivity along Bohai coast us- ing costal sensitivity index（CSI）, rock type, coastal slope, geomorphology, shoreline change, sea level rise, mean wave height and mean tide range were adopted and combined to calculate sensitivity value for 479 grid cells. In this study, rock type, coastal slope, geomorphology, shoreline change representing coastal structure variables, sea level rise, mean wave height and mean tide range as coastal process variables were ranked and combined to compute CSI indexes using an equal contribution product model, and the resulted index values were presented in a form of five quarter classification. Results showed that the general relative sensitivity spa- tial pattern were similar to each other for the three combination methods although some places have minor dif- ferences. The lowest grid appeared at the steep rocky coast in the Changxing island of Liaodong Peninsula while the highest grid is located at the muddy plain of Yellow River Delta in the Bohai Bay. The number of dis- crete values was increasing and the sensitivity range was also enlarged when the variables increased or replac- ing rock type with shoreline change. Therefore, increasing the number of variable and replacing rock type with shoreline change could enhance the discriminate power of sensitivity index, but there were no significant changes to general relative sensitivity spatial patter. On the whole, rocky cliff coast in Jiao uplift and Daxingan- ling-Taihangshan uplift zone have relative low sensitivity, while plain coast along Liaodong bay and Bohai bay in Bohai, Huabei subsidence area have relative high sensitivity. This paper could not only enable coastal plan- ner and manager to identify high sensitivity area for adopting measures to relief coastal pressure, but also pro- vide a foundation for further vulnerability research of estuary ecosystem. If social variable are considered to be combined, the vulnerability research of coastal system could be further improved in the long run.