基于不同岸线类型的象山港岸线提取及变化研究

Study on Coastline Extraction and Change of Xiangshan Bay Based on Different Coastline Types

本文提出了一种结合实地考察海岸类型的岸线遥感提取方法来对象山港区域岸线进行提取,根据研究区内实地考察获取的不同海岸类型特征,对Landsat卫星数据采用不同的处理方法进行岸线提取:基岩海岸和人工海岸采取OTSU变换;砂质海岸和淤泥质海岸采取MNDWI,处理后采取改进的Canny边缘检测算子进行水边线提取。研究结果表明:使用此方法提取出的岸线与真实岸线贴合程度较好。此外,对得到的象山港区域岸线进行分析后发现,2002—2017年其自然岸线占比呈下降趋势,而人工岸线占比呈上升趋势。

This study proposes a coastline remote sensing extraction method combined with field investigation of coastal types to extract the shoreline of Xiangshan Bay area.According to the characteristics of different coastal types obtained from field investigation in the study area,different processing methods are used to extract the coastline from Landsat satellite data:OTSU transformation is adopted for Bedrock Coast and artificial coast;MNDWI is adopted for sandy coast and muddy coast,the improved Canny edge detection operator is used to extract the water edge after processing.The results show that the coastline extracted by this method fits well with the real coastline.In addition,after analyzing the obtained regional coastline of Xiangshan Bay,it is found that the proportion of natural coastline shows a downward trend from 2002 to 2017,while the proportion of artificial coastline shows an upward trend.