Print Email Facebook Twitter Morphodynamic modeling of a large inside sand bar and its dextral morphology in a convergent estuary: Qiantang Estuary, China Title Morphodynamic modeling of a large inside sand bar and its dextral morphology in a convergent estuary: Qiantang Estuary, China Author Xie, Dongfeng (Zhejiang Institute of Hydraulics and Estuary) Gao, Shu (Shanghai Estuarine and Coastal Science Research Center) Wang, Zhengbing (TU Delft Coastal Engineering) Pan, Cunhong (Zhejiang Institute of Hydraulics and Estuary) Wu, Xiuguang (Zhejiang Institute of Hydraulics and Estuary) Wang, Qiushun (Zhejiang Institute of Hydraulics and Estuary) Date 2017 Abstract We investigate the evolution of a large-scale sand body, a unique type of sandbars in a convergent estuary. Specifically, we analyze and simulate the sand deposition system (defined as an inside bar) in the Qiantang Estuary (QE) in China. The deposit is 130 km long and up to 10 m thick, and is characterized by a dextral morphology in the lower QE. Numerical simulation is carried out using an idealized horizontal 2-D morphodynamic model mimicking the present QE settings. Our results indicate that the morphological evolution is controlled by the combination of river discharge and tides. The seasonal and inter-annual cycles of river discharges play a major role on the inside bar evolution. The bar is eroding during high river discharge periods but accretion prevails during low river discharge periods. Meanwhile, the highest part of the sand body can move downstream or upstream by several kilometers, modifying the seasonal sediment exchange patterns. We also show that the Coriolis force plays an important role on the dextral morphology patterns in wide, convergent estuaries. It induces a significant lateral water level difference and a large-scale gyre of residual sediment transport. Subsequently, the seaward tail of the inside bar shifts southward to help create a condition for the development of tidal flats in the lower reach of the estuary. The lateral bed level differences induced by Coriolis force are up to several meters. Coriolis effects also modify the behavior of flood and ebb tidal channels. To reference this document use: http://resolver.tudelft.nl/uuid:1b006605-b709-4cad-a2be-c6f051d404ca DOI https://doi.org/10.1002/2017JF004293 Embargo date 2018-01-10 ISSN 2169-9003 Source Journal of Geophysical Research: Earth Surface, 122 (8), 1553-1572 Part of collection Institutional Repository Document type journal article Rights © 2017 Dongfeng Xie, Shu Gao, Zhengbing Wang, Cunhong Pan, Xiuguang Wu, Qiushun Wang Files PDF Xie_et_al_2017_Journal_of ... urface.pdf 2.46 MB Close viewer /islandora/object/uuid:1b006605-b709-4cad-a2be-c6f051d404ca/datastream/OBJ/view