Spatio-temporal characteristics and causes of changes in erosion-accretion in the Yangtze （Changjiang） submerged delta from 1982 to 2010  

作　　者：SUN Xiaojing WANG Jun LI Mengya ZHENG Lu 

机构地区：[1]School of Geographic Sciences, East China Normal University, Shanghai 200241, China [2]Key Laboratory of Geographic Information Science of Ministry of Education, East China Normal University, Shanghai 200241, China [3]Department of Chemistry, East China Normal University, Shanghai, 200241, China

出　　处：《Journal of Geographical Sciences》2015年第8期899-916,共18页地理学报（英文版）

基　　金：National Natural Science Foundation of China, No.71373084; Global Change Scientific Research Program of China, No.2010CB951204; Innovation Program of Shanghai Municipal Education Commission, No. 13ZZ035.Acknowledgements The authors are grateful to Professor Xu Shiyuan of School of Geographic Sciences, East China Normal University, China, and Professor Yu Zhiying of State Key Laboratory of Estuarine and Coastal Research, East China Normal University, China, who gave us great help on this research and constructive advice to the paper.

摘　　要：The Yangtze delta＇s response to accelerating river damming and irrigation is a topic of global concern. This research analyzed the general erosion-accretion of the submerged delta front, the spatio-temporal changing pattern in different sub-regions, the geomorphological changes in typical cross-sections, and the geomorphological causes of the four main sub-regions（the eastern tidal wetland of Chongming–CM, the Hengsha shoal–HS, the Jiuduansha wetland–JDS, and the eastern tidal wetland of Nanhui–NH）. Data sources include topographic data measured at high-resolution, sediment load at Datong Station, and the corresponding estuary construction information. Major findings are：（1） in general, the study area had slightly eroded（the erosion area ratio was 51.83% and the accretion area ratio was 48.17%） from 1982 to 2010, and it had experienced a shift of “erosion-accretion- erosion”. The spatio-temporal change of geomorphology was also significant in the eight sub-regions, excluding constant erosion in the North Channel;（2） evolution in eastern and northern CM and HS, northern JDS, and the region within the 5 m isobath of NH was dominated by vertical deposition, which was the opposite of that in southern CM and HS, and the region within the 5 m isobath of eastern and southern JDS;（3） on the whole, the encompassed surface areas（ESAs） of the 2 m and 5 m isobaths kept increasing, and the annual growth rates reached 10.42 km^2/yr and 7.99 km^2/yr respectively during 1982–2010（however, four sub-regions exhibited disagreements）, and in the whole region and all sub-regions, the ESA of the 10 m isobath decreased, while the ESA of the 15 m isobath changed slightly during the period and remained stable;（4） being less influenced by the estuarine engineering, CM was the only sub-region where the ESA of the isobath decreased in accordance with the decline of the sediment load. Major conclusions are that estuarine engineering projects play an increasingly important role in affecting thThe Yangtze delta＇s response to accelerating river damming and irrigation is a topic of global concern. This research analyzed the general erosion-accretion of the submerged delta front, the spatio-temporal changing pattern in different sub-regions, the geomorphological changes in typical cross-sections, and the geomorphological causes of the four main sub-regions（the eastern tidal wetland of Chongming–CM, the Hengsha shoal–HS, the Jiuduansha wetland–JDS, and the eastern tidal wetland of Nanhui–NH）. Data sources include topographic data measured at high-resolution, sediment load at Datong Station, and the corresponding estuary construction information. Major findings are：（1） in general, the study area had slightly eroded（the erosion area ratio was 51.83% and the accretion area ratio was 48.17%） from 1982 to 2010, and it had experienced a shift of “erosion-accretion- erosion”. The spatio-temporal change of geomorphology was also significant in the eight sub-regions, excluding constant erosion in the North Channel;（2） evolution in eastern and northern CM and HS, northern JDS, and the region within the 5 m isobath of NH was dominated by vertical deposition, which was the opposite of that in southern CM and HS, and the region within the 5 m isobath of eastern and southern JDS;（3） on the whole, the encompassed surface areas（ESAs） of the 2 m and 5 m isobaths kept increasing, and the annual growth rates reached 10.42 km^2/yr and 7.99 km^2/yr respectively during 1982–2010（however, four sub-regions exhibited disagreements）, and in the whole region and all sub-regions, the ESA of the 10 m isobath decreased, while the ESA of the 15 m isobath changed slightly during the period and remained stable;（4） being less influenced by the estuarine engineering, CM was the only sub-region where the ESA of the isobath decreased in accordance with the decline of the sediment load. Major conclusions are that estuarine engineering projects play an increasingly important role in affecting th

关 键 词：erosion wetland submerged delta tidal Yangtze eastern topographic excluding experienced 

分 类 号：P315.5[天文地球—地震学] S157.1[天文地球—固体地球物理学]