Yangtze Delta Saltwater Intrusion

Saltwater intrusion regular and influence factor in Changjiang estuary are analyzed by field data, based on the previous study.A 2-D depth-integrated numerical model is developed to compute saltwater intrusion. By the field data process, the longitudinal salinity gradient is reduced from down to up, varied horizon salinity diffusion coefficient is adopted accordingly. The result of salinity verification is fitted with the observed data.Neap tide and spring tide in flood season and dry season are respectively computed in Changjiang estuary by the model. Saltwater intrusion in each passage is analyzed, the effect of discharge and tide can be gained. At mouth bar of estuary, saltwater intrusion in channel and bar is also analyzed.The computation results are able to reproduce essential features of tidal current and water intrusion in Changjiang estuary.