CHARACTERISTICS OF COASTAL EROSION AND DEPOSITION PROCESSES AT NANHUI FORELAND IN THE CHANGJIANG ESTUARY, CHINA

摘要

The Nanhui foreland located between the Changjiang Estuary and the Hangzhou Bay, is the prolongation in south of the Changjiang River Delta. It's the main passage of fresh water and sediment transportation into the Hangzhou Bay and southeast coast. Due to abundant sediment supply of the Changjiang River and with the extension of the Changjiang River Delta to the sea, the sea bed of this area was continually deposited before 1990. Because of the decrease of sediment flux from the Changjiang River after 1990's, the sea bed near the Nanhui foreland has been eroded instead of being deposited. On the other hand, the projects such as land using to accelerate the coastal deposit obstructed from sediment passing, so that the erosion process has been speeded. From now on, some big projects in the Changjiang estuary are under construction, the sediment flux into sea will keep at a low level in history, and the sea bed will be eroded sequentially. This phenomenon should be paid great attention to by the related marine engineering department.