Numerical Simulation Of The Effect Of Sea Level Rise On The Hydrodynamics Of The Pearl River Estuary

The Pearl River Estuary is located in Guangdong,Hong Kong and Macao in China.It is one of the most economically developed estuaries in China.And it is the general engine of economic development in South China.This is due to its superior geographical location and ecological environment resources in the estuary area,but it also faces many problems that are difficult to solve.For example,the saltwater intrusion during the dry season,the water pollution at the Pearl River Estuary and other problems.The above problems have brought negative effects on the economic and social development of the Pearl River Estuary.In addition,because the Pearl River Estuary is located at the sea-land junction,it is affected by runoff,tide,wave,wind and other factors.Moreover,the Pearl River system is complex,which can be divided into three rivers: the East River,the North River and the West River,and Eight outlets that is Humen,Jiaomen,Hongqili,Hengmen,Modaomen,Jitiimen,Hutiaomen and Yamen flow into the South China Sea,so the hydrodynamic conditions of the Pearl River estuary area are particularly complex.However,because the increase of global average temperature and the melting of a large number of polar glaciers,the global average sea level has risen,which has changed the hydrodynamic environment of the Pearl River Estuary,and it also has a profound impact on the natural environment and the economy and society of the Pearl River estuary.In this paper,FVCOM is used to study the impact of sea-level rise on the hydrodynamic and water environment of the Pearl River Estuary,in order to cope with the future changes in the hydrodynamic environment brought about by sea level rise in the Pearl River Estuary and the subsequent utilization of marine resources.The hydrodynamic model of the Pearl River Estuary and the nearby sea area is established by FVCOM.The data of tide level,current flow velocity and direction,temperature and salinity are compared and fitted.Based on the debugged numerical model,the impact of the sea level rise on the hydrodynamics of the Pearl River Estuary is studied.The results of research indicate: When the sea level rises 1 meter,the tidal range and velocity of the estuary area become larger,the arrival time of the highest and lowest tide levels and the direction of the current flow are 10-20 minutes ahead of schedule.The movement state of the particle track in the waters near the eight outlets basically does not change,but the total length of the particle track increases,the residual current in the waters near the eight outlets decreases,while the residual current in the open sea area increases.When the sea level rises 1 m,the pollutant transport at the eight outlets is weakened,especially at Jiaomen,Hongqili,Hengmen,Hutiaomen and Yamen,where the river channel is narrow and the water depth is shallow.When sea level rises 0.6m,during spring tide,the salinity of surface and bottom layer in the north of the deep trough in the west of Lintin Ocean,the north of Huangmao sea,the outlet of Modaomen waterway increases by 2PSU,during neap tide,the salinity of surface and bottom layer in Modaomen waterway and the north of the deep trough in the west of Lintin Ocean increases by 4PSU,and in the north of Huangmao sea,the salinity of surface and bottom layer increases by 2PSU.When the sea level rises 1m,the surface and bottom salinity in the northern part of the west channel of Lintin Ocean and at the Hongwan channel increase 5PSU.During neap tide,the surface salinity in some areas of Hongwan channel increased by 13 PSU,the surface salinity in the north of the deep trough in the west of Lintin Ocean increased by 6PSU,the surface salinity in the north of Huangmao sea increased by 2 PSU,and the bottom salinity increased slightly compared with the surface salinity.