Analysis Of Coastline Changes In Shandong Peninsula And Typical Areas In China Based On Remote Sensing Images

With the rise of remote sensing technology,coastline change monitoring has developed from traditional field survey and GPS fixed-point line mapping to automatic human-computer interaction extraction based on remote sensing images,and the efficiency and accuracy of coastline extraction have been greatly improved.At present,the research on the extraction of small-scale and single-type coastline based on high-score remote sensing images has been deeply developed,and different types of coastlines have corresponding extraction methods.However,there is no clear research on how to select the remote sensing image with appropriate resolution to accurately extract the coastline with large area and high complexity.In this paper,a complete coastline change analysis system based on long time scale is proposed,and the accuracy verification and error analysis are carried out.The specific work is as follows:(1)This paper takes Shandong Peninsula as the main experimental area to extract large area and high complexity coastline by optimization method.Based on the existing water-land separation methods,the optimal separation methods for different types of coastlines are found through comparative experiments,and the sandy and cornerstone coastline sea-land separation is carried out by using the improved normalized differential water index(Modified NDWI)threshold segmentation.The edge detection algorithm(Canny)is used to separate sea and land from silt,estuary and artificial shoreline.The automatic water extraction index(AWEI)is used to separate the sea and land along the shoreline of the alpine shaded area.The object-oriented method is used to extract the coastline.The changes of the length and area of the coastline of Shandong Peninsula are qualitatively and quantitatively analyzed to provide a basis for tracking the morphological changes of the coastline of Shandong Peninsula.(2)This paper qualitatively and quantitatively analyzes the changes of coastline length and area of Shandong Peninsula,which provides a basis for tracking the morphological changes of Shandong Peninsula coastline.Firstly,the distribution characteristics and interannual variation of different types of coastlines in Shandong Peninsula are analyzed based on the extracted coastline vector data.Then with the End point change rate(EPR)in the digital coastline analysis system(DSAS),the overall changes in 2018 compared with 1984 are analyzed for the areas with obvious shoreline changes.The change of every seven years during the period is analyzed by means of linear regression change rate(LRR).With the help of the net coastline movement(NSM),the overall change of the coastal area caused by the change of coastline length in 2018 compared with 1984 is analyzed.(3)In this paper,the optimization method is used to extract the typical coastlines of the eastern coastal areas of China and the DSAS system is used to analyze the changes to verify the generality of the method.Among them,the area around the Bohai Sea is the largest inland sea area in China,which is used as a supplementary experimental area of Shandong Peninsula.It can not only verify the method of extracting the coastline of Shandong Peninsula,but also provide reference for the research of the coastline of the inland sea.In this paper,six most active coastal areas along the eastern coast of China from north to south are selected to verify the effectiveness and applicability of this method from the two first-level classification levels of natural coastline and artificial coastline respectively.