城市化进程下厦门市海岸线形态时空变化分析

Analyzing spatio-temporal changes in the shoreline morphology of Xiamen City in the context of urbanization

中国海岸线绵长,海洋资源丰富。厦门作为沿海城市,近年来,港口建设、临海工业、滨海旅游开发等活动的增加导致海岸线出现较大变化。高效、精确地测量海岸线的时空动态变化极具研究价值和实际意义。该文基于2005年、2010年、2015年、2020年4期Landsat遥感影像数据,利用面向对象的方法对海岸线进行提取,然后从海岸线长度、形态和陆地面积变化等方面研究海岸线的时空演变。研究结果表明,15 a间,厦门市海岸线时空变化特征显著。海岸线长度整体持续增长,先加速后减速,2010—2015年间变化最快,平均速率高达4.1 km/a,变化主要集中在大嶝岛和海翔码头附近。海岸线形态逐年趋于平整,湖里区变化最为明显。2005—2020年间,厦门陆地面积增长约24.5 km 2,翔安区陆地面积增长最大。海岸线的变化受到多种因素的影响,其中人口增长、经济发展、政策的出台和改变等都对海岸线的变化产生巨大影响。

China boasts long shorelines and abundant marine resources.Xiamen,a coastal city in China,has seen significant changes in its shorelines in recent years due to an increase in activities including port construction,coastal industry,and coastal tourism development.Hence,efficiently and accurately determining the spatio-temporal changes in Xiamen's shoreline holds critical research value and practical significance.This study extracted information on the shorelines from the Landsat remote sensing images in 2005,2010,2015,and 2020 using the object-oriented method.Then,it delved into the spatio-temporal evolution of shoreline length,shoreline morphology,and land area changes.The results reveal significant spatio-temporal changes in Xiamen’s shoreline over the 15 years.The shoreline length changed quickly and then moderately,peaking from 2010 to 2015,with an average rate as high as 4.1 km/a,primarily in the vicinity of Dadeng Island and Haixiang Pier.The shoreline morphology tended to be flattened year by year,with the most pronounced changes observed in Huli District.From 2005 to 2020,the land area of Xiamen increased approximately 24.5 km 2,with the most significant increase occurring in Xiang’an District.The changes in the shoreline were influenced by many factors,predominantly including population growth,economic development,and the introduction and change of policies.