how landforms created by river give reasons
Answers
Answer:
Meanders are bends in a river that form as a river’s sinuosity increases.
A meander forms when moving water in a stream erodes the outer banks and widens its valley, and the inner part of the river has less energy and deposits silt.
Meanders form a snake-like pattern as the river flows across a fairly flat valley floor.
The sinuosity of a river is a measurement of how much a river varies from a straight line.
Meanders are formed due to lateral erosion and as the erosion increases over the period of time, the meanders in the river again start flowing in the straight line.
Meanders formation is a self-intensifying process where a greater curvature results in more erosion of the bank which in turn results in greater curvature.
Oxbow lakes are an evolution of meanders that undergo extensive deposition and erosion
When the meanders cut from the main course and water accumulates in this pool then it resembles the shape of the oxbow.
Fan-shaped plains:
These are formed in the region where the Tributaries Rivers joins the main river.
These are formed due to the deposition of material carried by the Tributaries Rivers.
These flows come from a single point source at the apex of the fan, and over time move to occupy many positions on the fan surface.
This deposition resembles the shape a Fan like plains
Flood Plains:
These are formed due to the overflows of the river and flood in the nearby areas.
It is an area of low-lying ground adjacent to a river, formed mainly of river sediments and subject to flooding.
Floodplains are made by downstream travelling meanders.
Slit carried by the water gets deposited in flooded areas and formed flat plains on both sides of river.
The Gangetic plain is a flood plain.
Explanation:
Solution :-
1. The river starts to flow through a broad, level plain with heavy debris brought down from upper and middle courses.
2. Vertical erosion has almost stopped and lateral erosion still goes on.
3. The work of the river is mainly deposition, building up its bed and forming an extensive flood plain.
4. Landforms like braided channels, floodplains, levees, meanders, oxbow lakes, deltas etc. can be seen at this stage.