古洪水研究的关键是确定古洪水事件的识别标志。洪水可以造成古文化中断,还会在各种文物上留下洪水痕迹。山区河流古洪水产生的平流沉积在沉积层理、沉积体形状、颜色等沉积构造和粒度、分选性、矿物组合等沉积结构方面具有可识别的标志。在洪泛平原区,对古溃口扇采用沉积学、地球物理学方法研究其沉积结构,对确定古洪水事件具有积极意义;通过古洪水所产生的埋藏古树、泥炭及沉积物中花粉的研究也有助于对古洪水事件的识别。
Identification marks are the keys in the paleoflood research. Floods can cause ancient culture discontinuities and flood marks on some culture relics. Slack water deposits of paleofloods in mountain rivers are identifiable in the sediment constructure, such as graded bedding, depositional bodies shape and color, and the sediment texture, such as grain size, sorting and mineral composition. The study of the depositional structure of ancient crevasses splays by means of sedimentology and paleomagnetism is important for the floodplain. While the research on ancient trees, peats and pollens caused by paleoflood is useful to paleoflood discrimination.