Morphological change of Jiaozhou Bay from 1985 to 2020 and its driving factors as were revealed with GEE

ZHAO Shiqi; XU Yandong; CHEN Jianqiang; WEI Xiao; WANG Yuzhen

doi:10.13984/j.cnki.cn37-1141.2023.06.002

Abstract：The coastal area of Jiaozhou Bay(JZB)is occupied by the heaviest population and the most developed economy of Qingdao.It is of great significance to analyze the morphological change of the coastal marine environment protection and maintain the regional sustainable development.In this pa-per,we retrieved Landsat series remote sensing images from the cloud platform of Google Earth Engine(GEE),extracted the spatial information of gulf shoreline from 1985 to 2020,5 years each,automati-cally and comprehensively with maximum inter-class variance method,mathematical morphological method processing and Canny edge detection.The temporal and spatial variation process of JZB in 35 years was quantitatively analyzed from three dimensions,point,line and plane,and its driving factors were discussed.The results showed that the automatic interpretation of remote sensing images on GEE cloud platform can improve the extraction efficiency of gulf shoreline spatial information.From 1985 to 2020,the average direction of the center of gravity displacement of JZB was 7.61° north to east.The south bank of the bay expanded to the sea much more than the north bank did,and the west bank ex-panded to the sea slightly more than the east bank did.In the studying period,the length of shoreline,fractal dimension and bay morphological development index all maximized in 1990,and the shoreline length increased first,and rapidly decreased,slightly increased and slowly decreased then.In the stud-ying period,the development and utilization degree index of shoreline have been increasing,and the bay area decreased by 17.31％(70.34 km2).The main driving factors of the bay morphological change were reclamation activities including inshore breeding ponds,port projects,urban construction,coastal communication line construction among others.