Fluvial terrace is an abandoned floodplain with a long, narrow stairs that is formed when the river flowed at a higher level than at present. Fluvial terrace consists of two parts; a tread, which is the flat surface at the upper side of fluvial terrace, and a scarp, which is the steep slope connecting the tread to the downside. Fluvial terrace is divided into Rock terrace and Gravel terrace according to structure materials, and it is also classified as Tectonic terrace and Climate terrace according to causes of formation.