Pollutant Transport Modelling On The North Coast Of Hangzhou Bay

Pollutant transport is an important and basic topic in environmental problems. A comprehensive analysis system of pollutant transport has been developed. The system provides a framework to analyze and tidal current, residual flow, pollutant mixing area and distribution of heavy metal. The hydrodynamic model-POM simulates tide for the transport portion. The model contains an inbeded second moment turbulence closure sub-model to provide vertical mixing coefficients, a sigma coordinate is also used in that the vertical coordinate is scaled on the water column depth. The residual flow and its affected factors are detailed discussed and analysed. The pollutant mixing area is also given out in this study.The comprehensive study shows that on the north coast of Hangzhou Bay, residual flow field is affected by the runoff of the changjiang River, the wind stress and the different tidal moment. The mixing area is influenced both by The exchange of the water body and the turbulence conditions. From the point of pollutant transport, The east port of Jinshan is good for its quickly transportation and its self-purification capacity. Compared with four different tidal moment: at slack water in ebb tide and flood tide, the flood strength and ebb strength, the slack water in flood tide is the best moment for pollutant releasing and transport towards outside of the Bay. Though the results have been verified initially, due to lack of detailed data at residual flow and the trace of pollutant transport for a long period, detailed verifications is, for the Time being, impossible.