A STUDY ON SEDIMENTATION OF TIDAL MUD FLATS OF CHINA
Ren Meie (Nanjing University)
In China, progressing mud flat is greatly different from receding mud flat in width, morphology of profile, and size of sediment. This is a result of different hydrodynamic conditions. Wide tidal flats on the east coast of Liaotung Peninsula and west coast of Taiwan consist of fine sand and form a special type of flat in China.It is suggested that the following three topics are promising areas for future research:( 1 ) construction of observatory towers or platforms in typical localities for a whole-year measurement of a number of parameters of hydrology and sediment on the tidal flat.( 2 ) source of sediment of mud flatRecent data of clay-mineral assemblage and CaCO3 content confirm the conclusion that on Jiangsu mud flat north of Jianggang, sediments mainly come from the abandoned Huanghe, while material of the mud flat south of Jianggang derives chiefly from the Changjiang. Ca and CaCO3 contents of sediment of the tidal flat west of the Yalujiang mouth show that there sediment is from Yalujiang with little relation to Huanghe. Historical evolution of the Huanghe mouth and Changjiang mouth has exerted influence on sedimentation of mud flats of a wide area. It is a specially interesting topic for detailed studies.( 3 ) biological agent in sedimentation offers a new area for future research. Preliminary data collected from the mud flat of Jiangsu Province show that abundant benthic diatoms and a large number of molluscs and crabs on the flat may play an important role in the sedimentation of mud flats.