Spatial and temporal changes and the driving forces of coastline in China Bohai Gulf in recent 30 years

Abstract

The evolution of coastline reflects the influence of geology, rivers, climate, tides and sea level changes. Bohai Gulf is the core region of China Bohai Bay economic circle, so the research of coastline changes and the driving forces is of great importance for socio-economic sustainable development and regional environmental protection. Based on the technology of GIS and RS, coastlines in the year of 1979, 1989, 2000 and 2010 was interpreted from remote sensing images. By the analysis of spatial and temporal changes of coastline and the driving forces, this study shows that: (1) Compared with types and length of coastline in 1979, 1989, 2000 and 2010, the proportion of artificial coastline was 35.6%, 79.3%, 81.7 and 83.6% respectively, and it reflected a dramatic increased for artificial coastlines proportion during the past thirty years. (2) The length of coastline in the last two decades changed much faster than that in the first decade, and the length of coastlines during 1979–1989, 1989–2000 and 2000–2010 increased by 26.4, 128.0 and 120.0 kilometers respectively. (3) As a result of coastline changes, the land area increased by 760 square kilometers during 1979–1989, 424 square kilometers during 1989–2000 and 608 square kilometers during 2000–2010. (4) Result from coast erosion, land lost 66.2, 77.5 28.3 square kilometers during the year of 1979–1989, 1989–2000 and 2000–2010 respectively.(5) the driving forces for coastline changes have significant temporal heterogeneity: in the period of 1980 to 1990, the main driving force for coastline change was estuary sedimentation, especially in the Yellow river estuary, while the main driving force was tidal flat reclamation for aquaculture during 1990 to 2000, and the driving force for coastline change in the last decades was the interaction of aquaculture and port construction.