TY - JOUR
T1 - Response of suspended sediment dynamics to human activities in the transitional zone between Changjiang Estuary and Hangzhou Bay
AU - Xie, Dongfeng
AU - Chen, Yuwen
AU - Pan, Cunhong
AU - Zhang, Shenyang
AU - Wei, Wen
AU - Wang, Zheng Bing
AU - Gu, Jiali
AU - Duan, Wenyi
PY - 2024
Y1 - 2024
N2 - The Changjiang Estuary and Hangzhou Bay system has experienced river damming and estuarine engineering in the last decades. However, few studies focused on the shifts in its sediment dynamics due to such human activities. In this study multi-decadal development of sediment dynamics in the transitional zone of the two large estuaries was analyzed, based on the synchronous hydrographic data in the winter of 2023, 2014 and 1983. The results revealed significant changes in regional hydrodynamics and suspended sediment transport, despite the continuous good correlations between the current velocity, suspended sediment concentration (SSC), water/sediment fluxes and tidal range. Specifically, the current velocity has been decreased by 8 - 21% after 2014, mainly due to the land reclamation (implemented around 2016) with several groins stretching into deep water and altering alongshore hydrodynamics. The SSC has decreased further by 29 - 38% in addition to the significant decrease during 1983 - 2014. The SSC changes are related to the combination of river damming which induced sediment load reduction and land reclamation which enclosed a large amount of sediment. Furthermore, the sediment transport from Changjiang Estuary to Hangzhou Bay decreased by 36% - 53%, explaining the observed bed erosion in the northern bay mouth in recent years. The findings are also relevant for studies on sediment dynamics in other large estuaries worldwide.
AB - The Changjiang Estuary and Hangzhou Bay system has experienced river damming and estuarine engineering in the last decades. However, few studies focused on the shifts in its sediment dynamics due to such human activities. In this study multi-decadal development of sediment dynamics in the transitional zone of the two large estuaries was analyzed, based on the synchronous hydrographic data in the winter of 2023, 2014 and 1983. The results revealed significant changes in regional hydrodynamics and suspended sediment transport, despite the continuous good correlations between the current velocity, suspended sediment concentration (SSC), water/sediment fluxes and tidal range. Specifically, the current velocity has been decreased by 8 - 21% after 2014, mainly due to the land reclamation (implemented around 2016) with several groins stretching into deep water and altering alongshore hydrodynamics. The SSC has decreased further by 29 - 38% in addition to the significant decrease during 1983 - 2014. The SSC changes are related to the combination of river damming which induced sediment load reduction and land reclamation which enclosed a large amount of sediment. Furthermore, the sediment transport from Changjiang Estuary to Hangzhou Bay decreased by 36% - 53%, explaining the observed bed erosion in the northern bay mouth in recent years. The findings are also relevant for studies on sediment dynamics in other large estuaries worldwide.
KW - Changjiang Estuary
KW - Hangzhou Bay
KW - land reclamation
KW - sediment dynamics
KW - sediment load reduction
UR - http://www.scopus.com/inward/record.url?scp=85201966525&partnerID=8YFLogxK
U2 - 10.3389/fmars.2024.1440754
DO - 10.3389/fmars.2024.1440754
M3 - Article
AN - SCOPUS:85201966525
SN - 2296-7745
VL - 11
JO - Frontiers in Marine Science
JF - Frontiers in Marine Science
M1 - 1440754
ER -