Study on the spatiotemporal changes and impact of reclamation areas based on remote sensing

Using Landsat TM and OLI multispectral image data, the accuracy of extracting sea area from different water body indices is compared. Finally, the improved normalized water body index (MNDWI) is selected to study the dynamic characteristics of the coastline and the progress of reclamation of Dalian in 1996, 2005, and 2015. The results show that: from 1996 to 2005, the area of land reclamation in Dalian reached 31.58km2, and 83.55km2 for 2015-2015. It is mainly used for dock construction, industrial land, aquaculture ponds, port docks, construction sites, residents Land, commercial and financial land, etc.; from 1996 to 2015, the total length of the coastline increased by 132.77km. The length of the artificial shoreline increased significantly, with its continuity in spatial distribution increased; the length of the bedrock shoreline was reduced due to the destruction of reclamation projects. Although large-scale land reclamation has brought good economic and social benefits to the local area, it also has a large impact on the marine and forest ecological environment. It is recommended to moderately develop coastal zone resources and further strengthen monitoring and supervision mechanisms.