It was only a bayou in the ancient time and later on it became a lake for the tide had brought sand to the bayou.After numerous constructions, it became a semi-closed adlittoral lake.

古时为一海湾，挟带泥沙长期堆积形成“泻湖”，又经过历代不断疏浚建设而成为半封闭的水湖泊。