浙江三门湾湿地遥感时间序列演变分析

海湾湿地演变的时空特征分析,对明晰海湾资源环境基底、了解综合开发潜力,促进湾区可持续发展具有重要意义。以浙江三门湾湿地为研究区,利用1984—2019年Landsat TM/ETM+/OLI遥感影像数据,基于湿地地物光谱指数时间序列变化特征,对三门湾湿地信息进行提取并分析了其动态变化。结果表明：1984年以来三门湾湿地面积变化显著,主要位于宁海县南部、三门县东北部以及象山县西南部地区;从海湾面积变化趋势看,1984—2002年呈波动下降趋势,2003—2009年呈加速下降趋势,2010—2019年则呈平稳发展趋势。围填海等人类活动导致海湾形态变化显著,海岸带管理政策的供给过程变化成为海湾湿地演变的重要因素之一。研究可为后围填海时代湾区建设与海湾可持续发展提供决策支持。

Changes of wetland in the Sanmen Bay,Zhejiang province based on Landsat time-series remote sensing images

The bay is a unique strategic and ecological space in the coastal zone. Under the influence of global warming and intensified human activities, the shape and ecosystem of the bay have become more sensitive, fragile, and changeable. It is particularly necessary to clarify the temporal and spatial differentiation characteristics of wetland evolution in the bay areas under the influence of human activities and to find out the root cause of the wetland resource endowment. With the increase of satellite remote sensing data and the development of geographic analysis platforms (i.e., Google Earth Engine, GEE), rapid, low-cost, high-precision continuous monitoring of the evolution of the land surface becomes possible. The analysis of the temporal and spatial characteristics of the evolution of the bay wetland is of great significance for clarifying the resource and environmental base of the bay, understanding the comprehensive development potential, and promoting the sustainable development of the bay area. Taking the Sanmen Bay Wetland (SBW) in Zhejiang province as the study area, using Landsat TM/ETM+/OLI remote sensing image data from 1984 to 2019, based on the change characteristics of the spectral index time series, we extracted the information of the study area to examine its dynamic changes. The results show that the area of SBW has changed significantly since 1984, mainly found in the south of Ninghai county, the northeast of Sanmen county, and the southwest of Xiangshan county. In terms of the area, there was a fluctuating downward trend from 1984 to 2002, an accelerated downward trend from 2003 to 2009, and a steady development trend from 2010 to 2019. Human activities, such as reclamation, have caused significant changes in the shape of the bay, and the supply process of coastal zone management policy has become one of the important factors in the evolution of the bay wetland. The research can provide decision support for the construction of the bay area and the sustainable development of coastal areas in the future.