Point bar
Also called: Meander bar · Topic: Landforms and their Evolution: Rivers, Groundwater, Glaciers, Waves and Wind · NCERT: Class 11, Ch 6 "Landforms and their Evolution"
Meaning
A point bar is a deposit of mixed sand and gravel on the inner bank of a meander bend in a large river. Water flows slowly on the inside of the bend, so it drops its load there. As the outer bank is worn away, the point bar grows outward and the bend moves. Point bars have an almost even profile and width. Watch out: NCERT says point bars form on the "concave side", but they actually form on the convex (slip-off) bank. They are also called meander bars.
Example
Sandy point bars form on the inner bends of the Burhi Gandak near Muzaffarpur, Bihar.
Don't confuse with
- Undercut bank: this is the outer, concave bank of the bend, which is worn into a steep cliff. The point bar lies opposite it.
- Natural levee: a levee is a ridge along the river banks built by floodwater. A point bar is built inside the channel bend.
Related concepts
- Alluvial fan
- Distributary
- Delta
- Estuary
- Floodplain
- Natural levee
- Meander
- Slip-off slope and undercut bank
- Oxbow lake
- Braided channel