(1) 中国科学院烟台海岸带研究所

With the rapid socioeconomic development, human activities continue to expand from mainland toward the sea. In this context, reclamation has become an important way to solve the shortage of land resources in coastal areas. However, high-intensity and unreasonable reclamation has caused tremendous pressure on the eco-environment in the coastal zone. Timely and accurately monitoring regional reclamation is of great significance for the protection of coastal resources and the promotion of regional sustainable development. Shandong Province is a major marine province with a long history of reclamation, with prominent coastal eco-environment problems caused by reclamation. By summarizing the existing literature, we found that there are few studies focused on unraveling the human-environmetal laws of reclamation, especially in Shandong province. So we extracted the vector data of reclamation using remote sensing images, and analyzed the spatiotemporal dynamics along the mainland coast of Shandong Province from 1974 to 2017. The present study was based on RS/GIS technology, combined with a variety of data sources and aiming to inform reclamation management and related planning of the coastal zone in the study area. Results showed that: (1) The reclamation area of the mainland coast of Shandong Province had reached 4649.26 km~2 by 2017, presenting a sustained growth trend during the research period. The main type of utilization was sea-based reclamation. (2) Sea-based reclamation was mainly distributed in the Yellow River delta and the tidal flat areas of Laizhou Bay, while land-based reclamation was concentrated in the coastal areas of major ports and cities. The gravity center of reclamation moved from southeast to northwest during 1974-2017. (3) Frequent conversion from sea-based reclamation to land-based reclamation was prominent, and reclamation utilization types changed from being single to more diversified. The proportion of harbors, towns, industries, and other utilization types in reclamation development had increased rapidly, and the development of aquaculture and salt industry was no longer the main way. The reclamation utilization turned to be more comprehensive, diversified, and intensified. (4) Coastal reclamation in the whole province presented obvious multi-stage characteristics. Before 2000, reclamation in Shandong Province was mainly used to develop aquaculture and salt industry. While after 2000, especially from 2007 to 2017, the land-based reclamation area had increased rapidly, mainly used for port construction, urban and tourism infrastructure construction, and industrial development of coastal ports, due to the impact of the coastal development strategy, urbanization and industrialization. (5) The types of reclamation had been transformed between each other frequently. The new land in Shandong Province came not only from land reclamation to the sea, but also from the transformation of original reclamation types such as aquaculture ponds and salt fields.