Depositional Landforms produced in the Middle Part of River

  Depositional Landforms produced in the Middle Part of River 

When the river enters the plains after descending from the mountainous region, the amount of water in it has increased.  The velocity of the river also decreases as the slope of the river valley suddenly decreases.  In such a situation, erosion of the banks starts to increase more than the river bed.  More deposition than erosion is the predominant feature found in the intermediate part of the river.  The following landforms are composed in this part of the river.

1.Alluvial Fan and Alluvial Cone - When a mountain river enters the plain, the river begins to be unable to drain the depression as soon as the slope is low.  As a result, the river spreads its riverbed in a semicircular form outside the mountainous region known as the alluvial fan.  Almost all the rivers originating from the Rockies and Andes mountains
alluvial fan are composed.  In the foothills of the Himalayas several alluvial fan have formed the Bhavar region in the northern part of the Gangetic plain.
At times, alluvial fans become quite high and sharply shielded due to the accumulation of high river weights, called alluvial cones .  Alluvial cones are usually formed in semi-arid regions.  Several advanced alluvial cones can be seen in the foothills of the San Juan Mountains of America.

2. River Meanders - The word miyandar is derived from the Turkish river 'miyandar' In adulthood the river flows like a snake without flowing straight, which is called Meandering.  Due to the slow speed, the transport power of the river in the plains is so eroded that it diverts its stream instead of eliminating the obstacles in its path by erosion.  The river's own depression begins to block its path.Once the path of the river is diverted, then this process will not stop.  The reason for this is that the water flowing in the curve causes erosion on its outer or concave edges and greater deposition on the inner or convex edges of the curve.  Due to this, the water is deep and concave at the concave edges and the water at the convex edges is less deep and the stream is slow.  As a result, the eroded edge retracts and the deposited edge moves to the valley floor.  By this action, the winding of the river increases, which is called the river Visarp . 

3. Oxbow Lake - As river eruptions get larger, the wings of the eruptions get closer to each other .  River a short distance away Sets a long path for manifold.  When a flood occurs, the river cuts its narrow cervix and becomes straight.  The diagonal twist is left separately.  The ends of the severed erysipelas are filled with sand, mud and silt called Gokhur Lake or Chhadan Lake.  The shape of this lake is like the hoof of a cow.  It is also called Dead Lake, because over time it becomes dry and filled with sediments.

Landforms produced in the lower Part of River Valley

Due to negligible slope and low speed, the ability of the river to bear the load in this last part is greatly reduced.  In this part the river deposits the most and the erosion is negligible.  The landforms formed in the lower part of the valley are as follows

1. Braided River - The river in the lower part is unable to carry the river, so it starts to deposit the depression flowing on its own bottom. The stream of the  river begins to be blocked.  As a result, the river starts to flow in several streams.  These currents are separated from each other by sandblasts.  Such a river, which is trapped by many streams, is called a cave .

2.Natural Levees and Flood Plains - River when floods occur during the rainy season.  The water starts flowing out of its edges.  At the time of flood, both the amount of water in the river and the power of carrying the river are increased.  On flooding, the river becomes unable to transport so much of the alluvial and starts to deposit the rivers.  A thick layer of depression begins to freeze on the banks of the river because friction near the coasts.  (Friction) has the lowest water speed.  After repeated this sequence for many years, tall mounds are seen on the banks of the river which are called natural embankments .  Often these embankments are one or two meters high above the water level of the river, but sometimes their height is also higher than the roofs of nearby houses.  Natural embankments are sometimes artificially elevated and fixed.

3. Delta - The river has attained its base level before falling into a sea or lake.  At this time his power is very weak and velocity is very slow.  The river deposits all its remaining rivers at the mouth.  Due to the blockage of this depression, the river does not flow as a main stream, but instead flows into several small distributaries.  These branches also begin to deposit the load at their mouths.  Thus a triangular topography is formed over a vast area near the mouth, which is called delta .

This triangular form is called delta because the shape of the delta of the Nile River resembles the Greek word delta ().  The Ganges-Brahmaputra delta (1,25,000 sq km) is the largest delta in the world.  Not all rivers of the world form deltas.