Coastaline Extraction And Change Analysis Of Northern Jiangsu Based On Remote Sensing

The north coast of the northeast is dominated by silt coasts.In recent years,human activities have been the main driving force for the change of the coast of northern Jiangsu.Human activities are mainly represented by artificial reclamation,ocean engineering and reclamation.The traditional way of acquiring coastlines is mainly through manual field collection,which not only requires a lot of manpower and financial resources,but also Shoreline speeds cannot meet modern shoreline monitoring needs.Based on multi-source and multi-temporal remote sensing images,combined with RS(Remote Sensing)and GIS(Geographic Information System)technology,it is possible to extract coastlines with large spatial scales and achieve large-area simultaneous monitoring and rapid updating.This paper takes the North Jiangsu coast as the research area,Landsat MS,TM and Sentinel-2A Multi-source and multi-temporal remote sensing data such as MSI are used as data sources,combined with actual field survey data,based on RS object-oriented technology to extract 5th North Jiangsu in 1978,1988,1998,2008 and 2018 coastline,while using GIS technology analyzes the length changes of shoreline 5,the rate of shoreline and distance,and the reasons for the conversion of shoreline types.The shoreline segmentation analysis is carried out according to the variation characteristics of different estuaries.The main work contents and results are as follows:1.On the basis of multi-source and multi-temporal remote sensing data processing,the multi-scale segmentation and spectral difference segmentation in the surface object technology are used to segment the remote sensing data,reduce the “salt and pepper effect” of image classification,and improve the image classification accuracy.Calculate the B component index of the image and enhance the water body information to B as the threshold segmentation parameter,the volume is separated by water and land and the binarized image is obtained.Based on the morphological method,the waterfront line of the study area is obtained.2.The research area shoreline is divided into artificial shoreline and natural shoreline according to the interpretation mark.The artificial shoreline is subdivided into saltbearing embankment line,port terminal shoreline,river bank embankment line,construction embankment line and road seawall.On the shoreline,the natural shoreline of the study area is dominated by silt shorelines.According to the interpretation mark and the field survey data The waterside line gets the final coastline.3.Based on the coastline of the phase 5 study area,the GIS technology and the DSAS digital shoreline analysis system developed by the USGS are used to analyze the dynamic changes of coastlines in different periods,and the changes in coastline length in different periods of the study area are counted.Quantitative indicators of shoreline velocity and distance changes and shoreline type conversion.The results show:(1)The total length of the shoreline of the study area has generally shown a decreasing trend during the 40 years.In 1978,the total length of the study area shoreline was about 255.89 km.In 1988,it decreased by 24.97 km compared with 1978,with an average annual growth rate of 0.96%.From 1978 to 1988,the length of artificial coastline on the coastline decreased by 17.18 km,and the length of natural coastline decreased by 7.79 km.In 1988,the total length of the coastline was about 230.92 km In 1998,compared with 1988,the length of the coastline increased by 10.53 km,the annual average growth rate was 0.96%,the length of artificial coastline decreased by 12.71 km,and the natural coastline increased by 23.24 km.In 1998,the total length of the research coastline was about 241.45 km,1998.For 1988,the artificial coastline length decreased by 12.71 km,the annual average decreased by 0.53%,the natural coastline increased by 23.24 km,and the artificial coastline length decreased by 12.71 km.In 2008,the total length of the study area coastline was about 218.03 km.In 2008,compared with 1998,the coastline length decreased by 23.42 km,the annual average decreased by 1.07%,the artificial shoreline length increased by 40.79 km,and the natural shoreline length decreased by 64.21,which is the most obvious time interval.In 2018,the study area shoreline total length is about 22.57 km,in 2018,the coastline length increased by 2.54 km compared with 2008,the annual average increased by 0.11%,the artificial shoreline length increased by 11.92 km,and the natural shoreline length decreased by 9.38 km,which is the least significant interval.(2)Research area during in1978?018,the rate of shoreline propulsion into the sea area was much higher than that of the land area.From 1978 to 1998,the way of propelling the shoreline to the sea area was dominated by natural siltation.From 1998 to 2018,the shoreline was pushed to the sea area.Artificial cofferdams;1978?1988 the rate of advancement between the Sheyang River estuary and the Xinyang Port is the most obvious.It is propelled to the sea in a natural and long way,with an average EPR(End Point Rate)of 281.4(m/a).Between 1988 and 1998,Xinyang Port to the Doulong Port The rate of advancement is most pronounced,propelling to the sea in a natural,long way.The average EPR is 535.5(m/a);between 1998 and 2008,the propulsion rate between Doulong Port and Dafeng Port is the most obvious,and it is propelled to the sea by artificial cofferdam,with an average EPR of 502.1(m/a);In the period from 2008 to 2018,the Liangzhu River mouth to the side,The rate of advancement between the estuaries is the most obvious,and it is propelled to the sea by artificial cofferdam,with an average EPR of 347.7(m/a).(3)The change of the shoreline type in the study area is more obvious.The artificial shoreline and the natural shoreline are characterized by growth and weakening trend,respectively,in 1998?20.In the past eight years,the artificial coastline has continued to increase,with a total increase of 52.71 km in 20 years.The artificial shoreline type has the highest proportion of salt-cultured cofferdams;from 1978 to 2008,there is no portand-dock coast type,and the port terminal coast was added from 2008 to 2018.Type,the trend of increasing the number of artificial coast types on the artificial shoreline is in a state of elimination.4.The automatic coastline extraction software based on remote sensing data can realize the automatic process from downloading data to visualization of coastline,facilitate the extraction and analysis of coastline,and improve operational efficiency.