Analysis on the changes of coastline development intensity in China recent 25years

Coastline resources are the important spatial basis of socio-economic development and urban expansion, which have become the key factor in the socio-economic development of coastal cities.Based on remote sensing images extracted from 1990, 2000, 2010 and 2015, this paper calculates the change of the development intensity and the average annual variation rate of the coastline was calculated to study its spatial and temporal evolution characteristics in the past 25 years, and studies the temporal and spatial evolution laws of time and temporal evolution of the mainland coastline.The conclusions were followed:(1)China's coastline development intensity growth rate to maintain the growth trend, the spatial distribution of the Yangtze River estuary as the dividing line, the northern coastal cities generally higher than the south, the evolution of time and space showed the "three" and "two".(2)During the research period, the highly utilization coastline was mostly distributed in Shandong, Liaoning and Zhejiang provinces.The percentage of utilization in total length of developed coastline was larger over 70% in Tianjin, Jiangsu and Shanghai.(3)In the recent 25 years, the trend of the continental coastline development intensity index to Shanghai as the dividing line, The northern coastal cities was over 0.6, which was generally higher than the southern coastal cities.