Dawanggang beach dynamic analysis and ecologic reconstruction

Dawanggang,occurring as a sand bar(built up by the Luanhe River in the past time) adjacent to the Jing-Tang harbor,is located on the northwestern coast of the Bohai Sea.Since the Luanhe River changed its course to the north and also because of the construction of the Jing-Tang harbor wave dam to prevent sand accumulation,continental silt supply to the sand bar from the river has decreased and as a result,Dawanggang has been severely eroded and retreated.The authors use yearly beach monitoring data,multi-period aero-satellite pictutes interpretations and previous information to give a conclusion that mean annual erosion rate of the Dawanggang beach was-0.61～-5.30 m/a during the period of 1987-2009,and the erosion rate was the largest at the northeast end of Dawanggang adjacent to the wave dam of the Jing-Tang harbor,but the southwest end was stable due to artificial solidification.The authors also worked out a plan for ecologic reconstruction of the Dawanggang beach according to differences of erosion at different beach sections.