Research on Fluctuation of Suspended Sediment Concentration in Xuliujing
Shoal and Groove of Yangtze River Estuary
Abstract
In order to study the fluctuation law of suspended sediment
concentration ( SSC) of different water layers in Xuliujing
marginal shoal and deep groove of Yangtze River Estuary with time under
spring, middle and neap tides, and analyze the relevant factors of
SSC fluctuation in shoal and groove, so as to help calculate and
calibrate line computation of SSC, infer continuous sediment
transport rate and compilate sediment discharge in Xuliujing section,
provide theoretical basis for scientific research on analysis of Yangtze
Estuary channel erosion and deposition and river regime change, river
regulation and wading projects plan. Used horizontal sampler, bottom
sampler and other instruments to conduct on-site hydrological and
sediment tests of 1#(marginal shoal) and 4#(deep groove) measuring
verticals on Yangtze Estuary Xuliujing Section. The research conclusion:
the maximum correlation between SSC and flow velocity reaches
90.5%, SSC fluctuation degree increases with the increase of
flow velocity, SSC fluctuation peaks in marginal shoal mainly
occur at high flow velocity, SSC fluctuation peaks in deep groove
mainly occur at low flow velocity; The maximum correlation between
SSC and water depth reaches 99.7%, fluctuation degree increases
with the reduction of distance to bottom, fluctuation in marginal shoal
is more violent than deep groove; Occurrence time of SSC
fluctuation peaks is related to sediment d 50 and
sediment transport between shoal and groove; Spring and middle tides are
the time when shoal and groove SSC fluctuation degrees reach
their maximum, 28h, 17h, 14h and 14h, 8h, 5h fluctuations are main
patterns of shoal and groove SSC variation.