Extraction and spatio-temporal change analysis of the tidal flat in Cixi section of Hangzhou Bay based on Google Earth Engine
ZHENG Xiucheng1,2,3(), ZHOU Bin1,2,3(), LEI Hui1,2,3, HUANG Qiyu3, YE Haolin3
1. Institute of Remote Sensing and Earth Science, Hangzhou Normal University, Hangzhou 311121, China 2. Zhejiang Provincial Key Laboratory of Urban Wetlands and Regional Change, Hangzhou 311121, China 3. School of Information Science and Technology, Hangzhou Normal University, Hangzhou 311121, China
At present, the common methods for extracting tidal flats using remote sensing images tend to estimate tidal flat boundaries. Therefore, it is difficult to ensure high extraction accuracy. This study combined remote sensing cloud computing platform Google Earth Engine with the geographic information system (GIS) technology and selected 77 Landsat images during 1990—2021. Meanwhile, the mean high-tide line was set to the artificial coastline obtained through visual interpretation, and the mean low-tide line was determined through the fitting of the shoreline. Based on these, this study extracted the tidal flat in the Cixi section on the south bank of the Hangzhou Bay and estimated its area. Furthermore, this study analyzed the spatio-temporal changes in the area of the tidal flat. The results are as follows. During 1990—2021, the area of the tidal flat in the Cixi section on the south bank of the Hangzhou Bay was roughly maintained in the range of 20 000~24 000 hm2, and the tidal flat migrated from south to north at a speed of 286.9 m·a-1. The main driving force behind the spatial and area changes of the tidal flat was local policies.
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2022, Vol. 34 
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