The processes that are both artificial denudation and artificial accumulation to original geomorphy were uninterrupted, and original geomorphy was eroded by floodwater. 我国绝大多数挡水工程仍是各种土料堆筑而成,它们在抵御洪水突袭时,常有渗漏穿孔险情发生而使人措手不及。
A flood is an overflow of water that submerges land which is usually dry. The European Union (EU) Floods Directive defines a flood as a covering by water of land not normally covered by water. In the sense of "flowing water", the word may also be applied to the inflow of the tide.