The characteristics of modern coast erosion-accretion change near the Xiuzhenhe River Estuary

According to the historic map of 1963 and 1984 and the survey result of the coast in 2002,and the flight photo taken by Jiangsu Province Bureau of Surveying and Mapping in 1980 and taken by Shandong Province Bureau of Surveying and Mapping in 1997,and the observation results of the coastal landform in July,2002 and April,2003,the erosion-accretion change characteristic of the coast near the Xiuzhenhe River Estuary can be analyzed.The results show that:the coast in the study area can be divided into five segments:the dune coast in the north of Dongpanjia Village,the bedrock cape coast from Dongpanjia Village to Lanshantou,the estuary coast in the Xiuzhenhe River Estuary,the silty coast from Xiuzhenhe River Estuary to Daxinzhuang and the erosive coast from Daxinzhuang to Hankou.And there are different characteristics in each segmental coast.The dune coast in the north of Dongpanjia Village is now in erosion and average rate of erosion is 6～8 m/a;the bedrock cape coast from Dongpanjia Village to Lanshantou,outside the region impacted of human activities,change little:the low tidal line retreated 40～100 m from 1970 to 1974.In the west of Lanshantou,the coastline retreated 360～540 m from 1963 to 1984.The coastline has been in stability near the artificial sea wall since Lanshan Port built.The change of the coast in the Xiuzhenhe River Estuary are mainly impacted by human activities.The coast from Xiuzhenhe River Estuary to Daxinzhuang is in accretion;the coast from Daxinzhuang to Hankou is in erosion and has been retreated since 1963.Human activities in the study area are mainly building artificial dikes and dredging sands.Building dikes is good to stabilize the coast in certain extent;dredging sand directly aggravate the coast erosion.In the end,we suggest that the interrelated departments should make measure to stop dredging sand and in order to reduce the coast erosion and make the coast stabilization.