Coastal Erosion Research Of Weizhou Island In Beihai, Guangxi Province

With costal zone being the integral part of human life, problems of coastal erosion has aroused people’s attention as it keeps growing worse globally, and about 70% percent of sandy coast in China has already been eroded.Guangxi Province is one of the eleven coastal provinces in China, but the coast in Guangxi is being eroded continuously. Weizhou island locates in Beihai city, Guangxi province. Inhabited and far offshore, regional activity in there is relatively closed.As a result, the influence of costal erosion to the society,environment and economy in Weizhou island can not be ignored.Depended on the Marine public welfare industry project of “Typical island geological disaster monitoring and early warning model research in China ”,this article makes comprehensive investigation on the shoreline of Weizhou island, including large area of exploration、analysis of remote sensing images、measurement of profiles and shorelines、granularity research. Based on the accurate field data obtained therein, and combing previous experience and researches, this article analyzes the current situation and characteristics of the erosion in the shoreline of Weizhou island, and make suggestions about the prevention of coastal erosion in the studied area mentioned above.The study shows that the sandy coast is being eroded entirely while the number of artificial coast grows fastly in the studied area.Long-term and short-term changing features in the studied area is obtained through four times’ repeated measurements and contrastive analysis of the 15 beach profile setted from 2006 to the year of 2013.Long-term characteristics of shoreline profiles change indicate that the east and southwest part of Weizhou island shoreline are seriously eroded, and the southwest coast erodes 0.18m/a; in comparison, the northern shoreline is mildly eroded, and nearby the south bay, the whole shoreline is slightly changed, assuming a weakly erodent and alluvial status. Under the influence of short-term tropical storm, the coastal line is significantly eroded from winter to summer.Based on the above research and discussion, we come to the conclusion that rising sea level globally, storm surge, artificial sanding make up the mean reasons for costal erosion happening in Weizhou island. Artificial dikes and filling sand are recommended to be the best way to prevent erosion.