海南岛海岸线变迁遥感监测与分析

Coastline change monitoringand analysis with remote sensingin Hainan Island

监测和了解海岸线的动态变化对海岸带防护、海岸资源的合理开发和利用具有重要意义。本文以Landsat TM/OLI影像为数据源,通过Canny边缘检测算子提取1990年、2000年、2010年和2015年的海南岛海岸线,获取岸线长度以及陆地面积变化等信息,分析了海南岛25a年来的海岸线时空变化特征。结果表明:1990—2015年海南岛海岸线总长度增加33.58km,海岸线总体向海推进,沿岸陆地面积呈增加的趋势;岸线变迁主要集中在北岸和东岸,人工岸线长度增长显著,淤泥质岸线等自然岸线长度减少;海岸线变化主要受人为因素影响,海岸开发方式呈现出多样化,以围垦养殖、城镇建设和港口码头建设为主。

Monitoring and recognizing the dynamic changes of coastline are vital for the protection of coastal zones and the rational exploitation of coastal resources.In this study,Canny edge detector was used to extract the coastline data of the Hainan Island in 1990,2000,2010 and 2015 from the data source of Landsat TM/OLI images.Then,the changes of coastline length and land area were obtained to analyze the characteristics of temporal and spatial variations regarding the coastline of the Hainan Island over the past 25 years.The results show that the total length of the island＇s coastline had increased by 33.58 km from 1990 to 2015,with the coastline expanding outwards and the offshore area increasing in size.The changes mainly happened in the north and the east coasts where the artificial coastline had evidently increased and natural coastline such as muddy coastline diminished.Largely affected by human factors,the coastal development was diversified in patterns,with pond farming,construction of cities and towns,ports and piers as the main forms.