Changing of shoreline during the Late Quatemary in relationship with geodynamics and their affect to the coastal environment of the Red River

Abstract

In many years, changing of shoreline has caused a lot of difficulties for the sustainable development of socio-economics in the coastal zone of the Red River delta. Here, in after the Flandrian transgression, accretion process of expanding delta has continuously deve1oped. The eroded sections of shoreline appeared at the beginning of the Twentieth century (1905). The most intensive segment is in Hai Hau district. The Erosion re1ated mainly to the lack of sediment caused by exogenous and human activities. Affect of endogenous process to erosion is very weak. The Erosion in Hai Hau has continuously developed because sediment at the Red River mouth is mainly being transported to the SW to the depth of 5-25m, 62 percent of which is transported cross-shore. In order to use land effectively in the coastal zone, at intensive eroded shorelines geotechnical measures have to be applied such as strong sea dyke and groins. In case of areas typhoon landing at the spring tide, people in the vu 1crable areas at the coast have to move to safe areas.