In general waders, habitat insides the cofferdam needs to contained three kinds of landscape element, which is body of water, vegetation and bare flats.

• 围堤内湿地植被覆盖率大于60%25或水面小于总湿地面积20%25后，鸻鹬基本不出现，必须含有水域、植被和裸地三种景观要素。