1976-2021年南澳岛海岸线时空演变及驱动因素分析

Spatio-temporal evolution and driving factors analysis of the coastline in Nan ao Island from 1976 to 2021

海岸线是描述海陆分界的重要地理要素之一,其在自然因素及社会经济因素的双重影响下发生着不同强度的动态演变。基于Landsat系列卫星遥感影像,通过RS、GIS技术结合实地勘察,分析了1976—2021年间南澳岛海岸线时空演变,并运用灰色关联分析法进行驱动因素分析。结果表明:1)45年来南澳岛海岸线变迁显著,长度增长了11.06 km,分形维数呈升高趋势;2)研究期内,岸线类型由基岩为主的自然岸线向人工岸线转化,岸线利用程度综合指数呈增长趋势,岸线结构呈单一至多元发展的态势;3)南澳岛海岸线演变有明显的镇区差异,后宅镇受人为因素影响大,其演变较为显著,云澳、深澳两镇主要受到自然因素影响,其演变较为缓慢;4)台风(自然灾害)以及人口数量是南澳岛海岸线演变的主要驱动因素。

Coastline is one of the important geographical elements to describe the boundary between land and sea.Under the dual influence of natural factors and socio-economic factors,coastline dynamic evolution of different intensities continues to occur.Based on Landsat series satellite remote sensing images,the spatial and temporal evolution of the coastline of Nan ao Island from 1976 to 2021 was analyzed by RS and GIS technology combined with field investigation,and the driving factors were analyzed by grey correlation analysis.The results show that:(1)In the past 45 years,the coastline of Nan ao Island has changed significantly.The coastline length has increased by 11.06 km,and the fractal dimension have generally increased.(2)During the study period,the type of coastline changed from natural coastline dominated by bedrock to artificial coastline,the comprehensive index of coastline utilization show an increasing trend,and the main structure of coastline development and utilization show a form of single to multiple.(3)The evolution of the coastline of Nan ao Island has obvious regional differences.That of Houzhai Town is greatly affected by human factors,and its evolution is more significant.The coastlines of Yun ao and Shen ao Towns are mainly affected by natural factors,and their evolutions are relatively slow.(4)Typhoon(natural disasters)and population are the main driving factors of the coastline evolution of Nan ao Island.