Evolution Pattern And Countermeasures Of Beach Erosion In The ChangJiang (Yangtze) Estuary

The coast which is the important zone existing the land-ocean interactions lies between two kinds of different landforms-ocean and continent. The estuarine beach is a special part of the coast. There are much high-denseness economic constructions and high-strength developments in the area of estuarine coast. Just for these reasons, the region has happened huge changes and the beach erosion is just an important change in estuary.Beach erosion is a prevalent natural phenomenon and a kind of natural calamities in estuary. It is an important content in researching estuary. Since the late 20th centuary, the velocity of the coastal line extending to the sea has been slower. Especially since from 1960, the condition of coastal line movement has reversed, now there are 70 percents of sandy coast and almost open silt-muddy coast being in erosion. Since 1980's, many literates have done much researches on open coast erosion and delta coast erosion. We have got some valuable achievements. But compare with foreign achievements and beach erosion becoming serious day by day, we should do much to improve research level not only in range but in profundity.This paper selects the complicated Changjiang estuary as the discussed object. By the way of using GIS and DEM, qualitative research combined with quantitative research, we have done some preliminary work.The work not only enriches the intension of estuarine and coastal research but provides scientific decisions for the sustaining development in the Changjiang estuary and the other similar estuaries.By the preliminary research, we get some recognition: While the North Branch is becoming extinct, the South branch the South and North Channel are in the steadily developing period. In comparison with the historical materials, we get the latest pattern of the beach erosion in the Changjiang estuary.According to the different facts influencing the beach erosion, we think there are four types of the beach erosion in Changjiang estuary. After researching the typical region, we raise some models of the beach erosion according to the section planes.Based on these, the paper discusses the evolution direction of the beach erosion. At last, we raise some countermeasures to manage the beach erosion in the typical region.