Analysis of China’s Coastline Changes during 1990–2020

As the boundary between sea and land, information on location type of coastline constantly changes with environmental in coastal zones. Monitoring long time series becomes important for monitoring assessment zone environment. In this study, Landsat images from five periods (1990, 2000, 2010, 2015, 2020) were selected analyzing length, sea–land pattern, index diversity, fractal dimension characteristics. Our conclusions are as follows: (1) The lengths entire artificial mainland China increased 30,041.22 km 10,022.49 1990 to 32,977.34 17,660.84 2020, annual change rates 97.87 km/year 254.61 km/year, respectively. From rate natural decreased 66.68% 42.29%, 33.32% 57.71%. (2) length 20,018.73 15,316.5 km; among types coastline, sandy bedrock most, at 2062.95 1815.8 km, (3) had a significant increase land area, net about 10,902.55 km2. (4) diversity continued decrease, structure tended be simple. was consistent trend which basically shows an increasing trend. Therefore, displayed upward also led simpler more complex shapes. Since first year SDGs (2015), growth has by 158.32 compared that 2010 2015. recent years, enacted number laws, regulations, action plans protect its it proposed proportion will no less than 35%. rapid development China’s areas drives construction cities but creates variety challenges ecological environment zone, management sustainable use resources should further strengthened.