Erosional plains are developments on the Earth’s surface caused by natural weathering of glacier activity, wind movement or water (sea, river & stream) torrent and are subdivided on the basis of the type of erosional agent. Here we will discuss the glacial plain, wind-eroded plain & alluvial plain. Erosional plains are likely to develop on landscapes that are relatively flat with low height elevations and shallow depressions. Some plains may develop below sea level but not higher than the surrounding region; this is a result of endogenetic factors and diastrophic movements.
Types of Erosional Plains
Alluvial Plain
The alluvial plain is an erosional plain that occurs from weathering caused by water currents in the sea, river or stream. Fluvial (water) movement comes from higher land regions and wear away landmasses to produce low relief plains. This is what is known as the alluvial plain. These landforms are made up of the deposition of sediment over a long period of time from the fluvial movement to form alluvial soil. An alluvial plain is characterized by its relatively flat and gently sloping landform and is normally formed at the base of a range of hills. Continuous fluvial weathering of these hills is what causes sediments to move and spread across lower levels to produce this type of plain. These plains are formed mostly by slow running rivers, as slower fluvial movement picks up less sediment off the river floor causing more particles to settle and develop into an alluvial plain. Areas where more particles are dropped off are sometimes referred to as flood plains, and the particles that settle are called alluvium.