Alluvial plain
An
alluvial plain is a relatively flat and gently sloping
landform found at the base of a range of hills. As the hills
erode due to
weathering and water flow the
sediment from the hills is transported to the lower plain. Various
creeks will carry the water further to a river, lake, bay, or ocean. As the sediments are deposited during flood conditions in the
floodplain of the creek, the elevation of the floodplain will be raised. As this reduces the channel floodwater capacity, the creek will over time seek new, lower paths, forming
meanders (a curving sinuous path). The leftover higher locations, typically natural
levees at the margins of the flood channel, will themselves be eroded by lateral stream erosion and from local rainfall and possibly wind transport if the climate is arid and does not support soil-holding grasses. These processes over geologic time will form the
plain - a region with little
relief (local changes in elevation), yet with a constant but small slope.
*
Alluvium*
Alluvial fan*
Alluvial deposit*A
thorough description of alluvial plains provided by the Regione Emilia-Romagna.
