Definition of Entrenched Meander:-
It is a winding, sinuous valley produced by the degradation of a stream with trenching into the bedrock by downcutting. (Strahler)
Could you identify/differentiate an entrenched meander from a flood plain Meander? Yes, you can.
1. Entrenched meanders doesn’t have any Ox-bow lake.
2. The river valley where an entrenched meandering continued must be deeper than an alluvial plain meander.
Let’s understand why such differences exist?
Tectonic disturbance:- Actually entrenched meanders are formed due to the tectonic disturbance i.e., upliftment of underlying river bed. When this happens the river gains its eroding power, rejuvenation, and it tries to reach its base level again and so starts to deepen the valley floor, instead of sideward erosion like an alluvial river. This cutting produces a steep-walled inner gorge. On either side of the gorge will be the former floodplain, now a flat terrace high above river level.
“Valley-bottom floodplains are not attractive for human settlements.” Why?
1. Valley-bottom floodplains, i.e., river terraces that formed behind an entrenched meander are made of very hard rocks. Not easy to till the land, unlike alluvial terraces.
2. Causes of downcutting and terrace formation include a period of uplift or a change in climate that affects the amount of runoff and sediment the river receives. Often they may be subject to annual flooding.
Thus, entrenched meanders are more aesthetically pleasing, but for human survival and living, alluvial meanders have no substitute.
If you have any questions/suggestions feel free to ask, by comments.