Characteristics and Exploration of the Geomorphological Evolution of Lingdingyang Estuary in Recent Decades

Abstract

Based on the underwater topographic data of Lingdingyang since 1970s, the new characteristics of the evolution of the swale in Lingdingyang estuarine bay were analysed and the causes of the evolution were discussed. The results indicated that the West Shoal silts eastward and southward, and its spreading speed gradually slows down after 1985. Area in the north of the West Shoal decreases gradually and the in the south of the West Shoal the shoal area increases gradually. Recently, in the north of the Middle Shoal scour occurred, while in the south silt is the primary evolution. The - 5m contour line of East Shoal has little variation, and the swale surface area is also decrease gradually. The average annual erosion and deposition of the East, Middle and West Shoals of Lingdingyang has a certain correlation with the annual average sediment discharge of the main hydrological stations upstream. The correlation of the West Shoal is the best, Due to the high intensity of reclamation, the channels of in the west of Lingdingyang extends significantly to the sea. The runoff channels in the West moves downward, and the sedimentation center of the West Shoal tends to moves southward.