What best accounts for the retreating of a waterfall?
1) meandering stream action
2) erosion of the stream bed
The best account for the retreating of a waterfall is the erosion of the stream bed.
Waterfalls are formed when a river or stream flows over a steep drop or a series of rocks, creating a vertical descent of water. Over time, the constant flow of water causes erosion, which is the wearing away of rock and sediment. In the case of a waterfall, erosion occurs primarily at the base of the waterfall, where the force of the falling water erodes and undercuts the underlying rock.
As the stream continues to erode the stream bed, the rocks and sediment are carried away downstream. This process weakens the rock and causes it to collapse under the weight of the waterfall. As a result, the waterfall retreats upstream over time.
While meandering stream action can contribute to the overall erosion of a landscape, it is not directly responsible for the retreating of a waterfall. Meandering streams tend to occur downstream of waterfalls, where the landscape becomes flatter. In these areas, the stream may change its course over time due to erosion and deposition, but it does not directly impact the retreat of the waterfall itself.