Land reclamation and risk assessment in the coastal zone of China from 2000 to 2010

Abstract

Monitoring and assessing of land reclamation are essential components of sustainable coastal management. In this study, satellite remote sensing data were used in combination with ground investigations to systematically obtain land reclamation data for the coastal zone of China from 2000–2010.Then, the spatiotemporal variation in land reclamation and morphology of the coastal zone was analyzed. Furthermore, a spatially explicit habitat risk assessment (HRA) model from the Integrated Valuation of Environmental Services and Tradeoffs (InVEST 3.0) suite of tools was adopted to evaluate the risk posed by land reclamation to key coastal habitats over these ten years. Our results show that (1) the overall land reclamation intensity was higher in the north and lower in the south. At the Sea Region level, both the sea-filling area and tidal flat reclamation area in the Bohai Sea were higher than those of the other three sea regions. At the province level, Hebei, Jiangsu and Tianjin provinces were the top three in sea-filling reclamation, while Liaoning, Jiangsu and Shandong exhibited the greatest increases in tidal flat reclamation; (2) 31.2% of land reclamation happened in the natural coastal zone, reducing natural coastlines from 54.6% to 44.1% between 2000 and 2010; (3) land reclamation posed a great risk to important coastal habitats. Half of the tidal flat and 5% of the mangrove habitats experienced a high risk from tidal flat reclamation and sea filling, while 43.1% of saline meadows were at high risk, mainly from agricultural development and industrial construction. We argue that regional development strategies played important roles in stimulating land reclamation from 2000–2010. Considering multiple social and ecological functions of the coastal zone, trade-offs between land reclamation and ecosystem conservation should be recognized.