基于遥感影像的浙江省三门湾近40年海岸线及海岸带时空变化分析

根据1985、1995、2005、2013和2020年的Landsat卫星图像，采用人机交互手段将三门湾海岸线分为基岩岸线、砂质岸线、淤泥质岸线、人工岸线和河口岸线。采用交互式监督分类将三门湾海岸带的土地利用分为水体、林地、裸地、建设用地和农业用地。研究结果表明：近40年三门湾人工岸线和基岩岸线变化最大，分别增加了80.3 km和减少了79.3 km；近40年三门湾海岸带面积累计增加了130 km2，建设用地和水体是围填海新增土地的主要利用类型，主要的土地转移形式为裸地向建设用地、农业用地的转变以及林地转为建设用地；近40年三门湾岸线分形维数由1.22减小至1.201，人工岸线比例和建设用地占比分别上升了13%和22.57%，总体上呈现向海推进、人工化加强的趋势。人类活动是造成三门湾岸线及海岸带变化的主要原因，随着对海岸带保护与合理利用的推进，三门湾海岸带开发利用格局正逐渐稳中向好。

Analysis of spatiotemporal changes of coastline and coastal zone in Sanmen Bay,Zhejiang Province in recent 40 years based on remote sensing

The coastline of Sanmen Bay in Zhejiang Province, East China was classified as rocky coastline, sandy coastline, muddy coastline, artificial coastline, and estuary coastline by human-computer interaction based on the Landsat satellite images of 1985, 1995, 2005, 2013, and 2020. The landuse types in the coastal zone of Sanmen Bay were classified as water bodies, forest, bare land, urban, and agriculture using interactive supervision. The results represent that rocky coastline and artificial coastline in the bay have been changed significantly in the past 40 years. Most prominently, the artificial coastline was increased by 80.3 km while the rocky coastline decreased by 79.3 km. The urban and water bodies were the major landuse of recently reclaimed area, which has extended the coastal zone of Sanmen Bay by 130 km2 in accumulation in the last 40 years. The conversions from bare land to urban, bare land to agricultural, and forest to urban are the primary land transfer types in the Sanmen Bay coastal zone. In the past 40 years, the fractal dimension of Sanmen Bay coastline has been decreased from 1.22 to 1.201, and the proportion of artificial coastline and urban has been increased by 13% and 22.57% respectively, in general trends of seaward advancement and rising artificiality/urbanization. Human activities are primarily responsible for the changes in the coastline and coastal zone land use of Sanmen Bay. With the implementation of protection and rational use of the coastal zone, the development and exploitation of the Sanmen Bay coastal zone has been gradually improving and stabilizing.