South Branch Of The Yangtze River Estuary Waters Of Dissolved Oxygen Dynamics Numerical Model Applications

Based on the environment model 'Femme', a 1-D budget model for the southern part of Yangtze estuary has been built, in which three state variables are considered. They are dissolved oxygen(DO, organic matter and salinity. In the estuary ecosystem, DO is decreased with the degradation of organic matter. Inflows include runoff from land, tidal flow, sewage discharge. The seasonal changes of DO, organic matter and salinity in Yangtze estuary have been modeled in this work. And the modeled results showed that in flood season the concentration of DO is lowest in the whole year; and the concentration of DO in summer time is lower than that in winter.The spatial distribution of DO is that the lowest concentration of DO is in the areas where there is much organic matter. The waste water, inflow, temperature and wind are the most important factors that influence the spatial and temporal concentration distribution of DO.