基于机载LiDAR与潮汐推算的海岸带自然岸线遥感提取方法研究

Natural coastline extraction based on airborne LiDAR data and tidal estimation

海岸线对于海岸带保护与管理具有重要意义。海岸线现场测绘施测周期长且在地形复杂的区域施测难度大,基于遥感影像的海岸线判绘对解译人员的要求高,难以获取严格意义的海岸线。针对上述问题,本文提出一种基于机载LiDAR与潮汐推算的自然岸线遥感提取方法:基于机载LiDAR系统获取的航空正射影像解译瞬时水边线,应用LiDAR系统提取的DEM和建立的高程系统转换模型,通过潮汐数据推算研究区域的海岸线。通过与"908专项"航空遥感调查岸线结果比对,按本文方法所提取的3种自然岸线(砂质岸线、基岩岸线和淤泥质岸线)的均方根误差分别为1.66,5.23和32.48m。结果表明,该方法可用于砂质岸线和基岩岸线的提取,且具有无需开展现场测量工作的优势,可提高海岸线提取的效率。

Coastline is of great importance for coast protection and management.Traditional coastline draughting methods are mainly based on field mapping and remotely sensed images.Field mapping is usually time consuming and difficult to carried out in complicated area.Coastline interpretation requires high criterion for operators and the proper coastline is hard to extract.Aiming at the problems mentioned above,a coastline extraction method for natural coastline based on airborne LiDAR data and tidal estimation was proposed and Feiyantan and Zhifu Island were chosen as study area in this research.Instantaneous water edge was firstly extracted from ortho-rectified images acquired by airborne LiDAR system.Coastline of study area was estimated through tidal data,by utilizing inter-conversion model of elevation system and DEM retrieved by airborne LiDAR system.Compared with ＂908 coastline＂,the RMSE of 3 types of natural coastline （sandy coastline,rocky coastline and silty coastline） extracted using this method are 1.66 m,5.23 m and 32.48 m,individually.Results show that the method established in this research is efficient and capable of extracting sandy coastline and rocky coastline,without the need of field mapping.