Defensive barriers would not necessarily require heavy investment; they could be mounds of sand several meters high located along and near the shoreline. In fact, in some areas of the US and other countries, only extensive dune fields and vegetated areas are used to separate buildings from the seashore.
防护性堤岸并不要求大手笔投资；它们可以是近岸地区几米高的沙堆。事实上，美国和其他国家的一些地区都使用纯粹的沙丘和植被区来分隔建筑和海岸。