西沙永乐群岛岛礁海岸线变迁监测与分析

我国对南海诸岛及其附近海域拥有神圣不可侵犯的主权,珊瑚岛礁的开发、利用与保护,具有重要的战略价值。研究充分利用遥感影像宏观、快速、直观等优势,通过自动化识别与人机交互解译相结合的方法,对西沙永乐群岛岛礁岸线变迁情况进行变化监测。结果表明研究区内存在珊瑚礁岸线、基岩岸线和人工岸线三类岸线类型,以珊瑚礁岸线为主。通过对各岛礁在不同时期海岸线变迁的幅度与速度情况进行对比分析,发现珊瑚礁岸线变迁幅度最为剧烈,主要受自然因素影响,淤涨与侵蚀变迁交替作用,该类岸线处于一种不稳定的状态,其淤涨速率在不同时期不同岸段差异较大;其次为人工岸线,随着海岛的开发建设日益频繁,对土地的需求量不断增加,填海造地速度与幅度也大大增加;基岩岸线基本无变化,相对稳定。

Monitoring and analysis of shoreline changes in Xisha Yongle Islands

China has indisputable sovereignty over the South China Sea islands and their adjacent waters.The exploitation,utilization and protection of coral reefs are of great strategic value.This paper makes full use of the advantages of remote sensing images,such as macroscopic,rapid and intuitive,and monitors the changes of the xisha yongle islands coastline through the combination of automatic recognition and human-computer interaction interpretation.The results show that there are three types of shorelines:coral reef shorelines,bedrock shorelines and artificial shorelines,mainly coral reef shorelines.Based on the comparative analysis of the amplitude and velocity of shoreline changes in different periods,it is found that the change amplitude of coral reef shorelines is the most drastic.Under the influence of natural factors,sedimentation and erosion change alternately,and the shorelines are in an unstable state,and the silting rate varies greatly in different periods and sections;Secondly,artificial shorelines also change dramatically.With the increasingly frequent development and construction of islands,the demand for land is constantly increasing,and the speed and extent of Filling Sea Engineering are greatly increased;The bedrock shorelines are basically unchanged and relatively stable.