Rejuvenation River!

RIVER REJUVENATION

river is to be rejuvenated when the base level that is flowing down to, is lowered. this can happen by uplift of land, or by a sea or lake that it is flowing into becoming lower. that makes the river suddenly start eroding its bed vertically faster as it gains gravitational potential energy. that causes effect such as meanders cut down as gorges, steps where river suddenly starts flowing faster, & terraces derived from old floodplains. Rejuvenation terrains usually have complex landscape, because remnants of older landforms are locally preserved. parts of flodd pains may be preserved as terraces along the downcutting stream channels. Meandering streams often become entrenched , so a product of older river system is found with step, very pronounced "V" shaped valley. Rejuvenation result from causes which are dynamic, eustatic / static in nature.

I. DYNAMIC : dynamic rejuvenation may be caused by the epeirogenic uplift of a land mass. there movements are either associated with neighbouring orogenic movements.

II. EUSTATIC : this rejuvenation results from the causes which bring worldwide decrease in sea level, & 2 types of such rejuvenation are recognized.

DIASTROPHIC EUSTATISM : it is the change in sea level due to variation incapacity of ocean basins.

GLACIO-EUSTATISM : is the change in sea level due to withdrawal of water into the oceans occupying the accumulation of successive ice sheet.

CHANGES OF STATIC :
- decrease in land
- increase in runoff because of rainfall
- increase in stream volume through acquisition of new drainage by stream diversion.