MONITORING THE DIFFUSION OF SUSPENDED SEDIMENTS AND STABILITY OF TIDAL RADIAL SAND RIDGES AREA USING MULTI-SATELLITE REMOTE SENSING DATA IN THE NORTHERN OF CHANGJIANG RIVER DELTA, THE SOUTH YELLOW SEA

摘要

Based on 10 Landsat TM tapes and images and MSS images, 10 NOAA tapes and images and 1 SAR image from 1973 to 1997, the diffusion of suspended sediments and the change of tidal radial sand ridges in the northern of Changjiang River delta, the South Yellow Sea were analyzed. The results showed that the diffusion of suspended sediments in this area are controlled by tide and net current and submarine topography. The distribution of suspended sediments has close relationship with submarine topography. The old Huanghe River and Changjiang River are main sediment supply in the formation of radial sand ridges. The evolution of the radial sand ridges can be divided into three stages since Yellow River changed its channel northward and went into the Bohai Sea. The radial sand ridges in the northern part of Jiangsu beach are famous for their special extension of sand ridges. They are dynamic geomorphologic system unusually in the world. It is hard to survey these sand ridges normally for the complicated landform and varied hydrodynamic environment. There are many sediment sources flowing into the area, which include sediments from modern river flux, beach and edge of sand ridges erosion, sediments re-suspension of sub-marine old delta and bottom of tidal trough etc., and continental shelf sand. The suspended sediment and its distribution are an important factor affecting the evolution of modem sand ridges, especially for re-suspended sediments. The paper is mainly to research the distribution and diffusion of sediments in the special area and its evolution using multi-satellite remotely sensed data.