Land use change and effect analysis of tideland reclamation in Hangzhou Bay

Since the beginning of the 20(th) century, tideland reclamation as a huge project has continuously extended from inland to the sea for the socioeconomic development, like Zhejiang, Jiangsu and other coastal regions in China. The increase of land area alleviated the contradiction of supply and demand between human and land, which provided the guarantee for agricultural production and industrial development. However, marine ecological environment has been seriously damaged due to the increasing scale of tideland reclamation. This paper took the Hangzhou Bay in the Yangtze River Delta as a study area to explore the evolution law, socioeconomic effect and eco-environmental effect of reclaimed land from 1985 to 2015. The result showed that as follows: (1) The area of tideland reclamation was 460.67 km(2) with 16.57% cultivated land and 15.93% construction land, and its land use was inefficient; (2) Land use change has spatial and temporal difference, the speed of tideland reclamation had been increasing from 1985 to 2015 in time and the scale of reclaimed land in the southern (84.07%) of Hangzhou Bay was larger than the northern region (15.93%) in space; (3) The evolution law of land use was from tideland to swampland and coastal waters to agricultural facility land, to cultivated land to industrial-mining land to idle land, rural-urban construction land, and formed obviously hierarchical structure; (4) Effect analysis of land use change found that the socio-economic effect had increased but the eco-environmental effect had decreased from 1985 to 2015, it reflected socioeconomic effect was acquired through sacrificing ecoenvironmental effect; (5) It pointed out the existing problems on land extensive inefficient, environmental degradation and economy excessive growth without scientific planning, and offered some suggestions in land comprehensive improvement project, industrial transformation and upgrading and scientific planning and legal safeguard to promote sustainable development in the Hangzhou Bay in the new period.