Tan C.,Sun Yat Sen University |
Tan C.,China Institute of Water Resources and Hydropower Research |
Tan C.,National Engineering Laboratory of Estuary Hydropower Technology |
Huang B.-S.,Sun Yat Sen University |
And 6 more authors.
Shuili Xuebao/Journal of Hydraulic Engineering | Year: 2013
The Modaomen Estuary, as one of the eight 'gates' which connects the complicated stream network of the Pearl River and the estuarine bays, is the most important in discharging freshwater and sediment into the estuarine bays. However, there is immense bar area evolved in the outer subaqueous delta. Consequently, the flood releasing safety is the most important issue in the regulation project of the estuary. This paper is to investigate the dynamics of flood releasing in the mouth bar of the Modaomen Estuary, as well as the morphological response of the mouth bar to the flood, based on the analysis of the field data collected in 2003 and bathymetric data of recent representative years. The results show that in the flood season the water column in the bar area was highly stratified, characterized as buoyancy plume, while the intruded salty water from the adjacent sea was blocked by the mouth bar. The water damming effects of the mouth bar on the flood was displayed as the raised low water level. The differences in the water levels at the Dahengqin and Makou stations during high and low tides corresponded well with the discharge of the Makou station. In flood seasons, the Modaomen Estuary is river dominated, and the flood is the main forcing agent which controlled the morphological evolution of the mouth bar. With the flushing of the flood, both the east and west channels devolved, especially the east channel, suggesting that the east channel was the main path for the flood releasing. The flushing of the flood on the Jiaobeisisha was also significant, especially the coastal barrier in a north-south direction can be easily separated. Under the effects of the flood flushing, the sub-distributaries of the west channel originally formed.