Numerical Study of Residence Time in Daliaohe Estuary

Residence time is an essential transport time scale in estuary, and it was calculated for five boxes in Daliaohe Estuary during dry, normal and rainy seasons using a three-dimensional convection-diffusion model based on FVCOM. The results show that the tracer would take about 25 days to get to the river mouth during the dry season, 14 days for the normal season, but only 8 days are needed for the rainy season. The runoff condition has a significant impact on residence time. The initial release time of the tracer also influences the residence time greatly, and the difference of residence time between the maximum ebb and flood tide could reach 7 days. The results can provide reference for researching the pollution process and the ecological restoration in Daliaohe estuary.