Historical changes of the length and fractal dimension of Chinese coastline since 1990

The shoreline change is an important reach issue in marine science. We selected nine images 371 King nearly 22 years, and then extracted shoreline. By studying the change law of length and fractal dimension of Chinese coastline nearly 22 years,we concluded the following conclusions: (1) the length of China's mainland coastline had basically growth trend; (2) the length of natural shoreline and estuarine shoreline are decreasing, but artificial shoreline length is increasing, whose growth rate is bigger than other's reduce speed; (3) the fractal dimension of Chinese coastline is basically in a growth trend, whose change trend is consistent with the length of the coastline.