Effect of Large Scale Reclamation on Hydrodynamic Circulation in Victoria Harbour of Hong Kong

Abstract:

A calibrated threedimensional hydrodynamic model for the Pearl River Estuary is used to study the changes in hydrodynamic circulation in Victoria Harbour due to the existing reclamation and the maximum possible Central reclamation.Compared to the situation in 1975 （before large scale reclamation）,the numerical solutions show the following key changes after reclamation: The peak flow at all cross sections along Victoria Harbour decreases by about 8%~17% with an average value 11.5% in the existing reclamation.The peak velocity in the eastern harbour near Lei Yue Mun decreases after existing reclamation because of the reduction of flow,but it increases in the central and western harbour due to drastic reduction in harbour width.There is a clear twolayer vertical salinity distribution in wet season due to the runoff from the Pearl River,but a quite uniform vertical salinity structure in dry season.Flushing time in Victoria Harbour will increase by about 30% in dry season and 50% in wet season after reclamation due to the flow reduction.In present coastline,the flushing time ranges about 1.5~2.5 days in wet season and 5~7 days in dry season.The tidal flushing rate and flow discharge in the harbour will be practically unchanged after further maximum possible Central reclamation.