The impacts of tide on the flow division at the apex of the Pearl River Delta.

Wei Zhang, Jing Du

Wednesday 1 july 2015

11:30 - 11:45h at Amazon (level 1)

Themes: (T) Water engineering, (ST) River and coastal engineering

Parallel session: 9C. Coastal engineering

This paper aims to quantify the tidal impact on subtidal discharge distribution at the bifurcations in the Pearl River Delta in different bathymetries. The Pearl River Delta (PRD) is a dynamically complex estuarine system located in the northern continental shelf of the South China Sea. Over past years, accelerated anthropogenic activities, such as sand excavation and reclamation, have exerted great pressure on the bathymetry in the Pearl River Delta. Thus the hydrodynamics changed obviously in this region. A 2-D flow numerical model covered the entire Pearl River Estuary was established to simulate the hydrodynamics driven by river discharge and tides in the delta channel network. The model was forced with tides at open sea boundaries and with measured river discharge at upstream locations. The model validation of water surface elevation and discharge are in reasonable agreement with the observational data, suggesting that the model is robust enough to capture the physical dynamics in the PRD. Results of distribution of river discharge indicate that in the whole PRD the tidal impact increases seaward and with the changes of underwater topography, this impact is more apparent. In general, the effect of tides is to hamper the discharge division that would occur in the case without tides.