基于多源信息的辽东湾顶东部海岸时空变化研究

Multi-Source-Based Space-Time Analysis of Shoreline Changes in Eastern Liaodong Bay Top

根据对辽东湾顶东部的实地考察,本文综合利用RS/GIS技术方法,提出了岸线解译原则,采用多期TM/ETM+影像、CEBERS-02B高分辨率多光谱影像等数据,提取了1979年-2011年逐年的矢量岸线,量化分析了综合开发治理下研究区的海岸变化,为综合治理提出了科学建议。研究表明,研究区:①岸线延续增长趋势,曲率变小,由自然圆滑变为平直曲折,围海造陆已逐渐脱颖而出为主要变化形式;②海岸变化时空分异,三角洲湿地退化从面积减少变为自然湿地向人工湿地转化、河口地区围海填土面积趋于指数增加、砂质岸段侵蚀在防浪堤作用下得到有效缓解,反映出在相对稳定的自然条件下,社会因素成为变化的主要推动力,不同政策和规划对岸线形态塑造的巨大差异;③针对强度大、速度快的人类活动,使用时间尺度小密度高的逐年监测与传统大尺度监测相结合的方法分析,对监测海岸线的开发和治理、及时调整应对岸线变化的措施有重要帮助。

Due to the development of the local economy and exploitation of the shoreline, Liaodong Bay has changed. The analysis of shoreline changes plays a pivotal role in the development of the economy and policy. Prior to the 1990s, wetland degradation, sandy shoreline erosion and man-made land projects were responsible for changes in Liaodong Bay＇s shoreline. We analyze changes in the shoreline across the study area, examining the impacts of comprehensive development and management, and raise scientific alternatives for improved outcomes. Since RS and GIS based spatial analysis can detect shoreline changes immediately and accurately, this research adopted band 7, band 4 and band 1 TM data to compose false color images using ArcGIS. We propose six principles to distinguish different types of shoreline. According to field surveys and monitoring data, we found that trends in the length of shoreline have not changed and show a consistent increase in length while curvature is declining. The shape of the coast has trended from arc to jagged and has been driven by man-made development. Wetland resources have been converted from dimension change to qualitative change. The area of man-made land has shown index increase and breakwater is effective to reduce erosion of the sandy shoreline. These patterns indicate that in a relatively stable environment, social and economic factors are the main causes of shoreline change. Different institutions and different shaping shoreline policies cause various impacts. A combination of short-term high-density shoreline detection and traditional large scale detection will be highly effective in analyzing the impact caused by human activities. Monitoring shoreline development and management as well as intervention will also benefit from combined detection.