Satellite derived coastal reclamation expansion in China since the 21st century

Abstract Since 2000, many coastal land reclamation projects have been implemented in China to alleviate the shortage of coastal land resources with rapid urban sprawl and economic growth. As a result, both the length and proportion of artificial shoreline increased significantly. Meanwhile, coastal reclamation inevitably brings some negative environmental and ecological issues, such as biodiversity loss, water pollution, and wetland degradation. In this study, based on the GlobeLand30 product and the OpenStreetMap based coastline data, we tracked the coastal reclamation expansion in China in the 21st century. Specifically, we analyzed the coastal reclamation intensity and coastal reclamation types of all coastal provinces in China, and explored the relationship between reclamation intensity and GDP growth to understand the reclamation status of coastal areas during 2000–2020. Our results showed that the total area of reclaimed land along the coast in China was 5135.31 km2, of which artificial land and aquaculture were two main land-use/land-cover (LULC) types, accounting for 71.89% of the total reclamation area. Among all coastal provinces, Tianjin exhibited the greatest reclamation intensity (i.e., 7.16 km2 km−1) and Zhejiang Province had the largest reclamation area (i.e., 1304.65 km2). We also found the positive correlation between economic development and coastal reclamation. In addition, the progress of coastal reclamation activities has been greatly slowed down owing to national policies released in recent years.