What best accounts for the retreating of a waterfall?
Only one answer is right
1) meandering stream action
2) erosion of the stream bed
Is the answer number 1?
http://www.world-of-waterfalls.com/what-happens-to-a-waterfall-over-time.html
To determine the correct answer, we need to understand the process of waterfall retreat. Waterfall retreat refers to the gradual backward movement of a waterfall over time. As water flows off the edge of a waterfall, it can erode the underlying rock, causing the waterfall to migrate upstream.
Out of the two options provided, number 1 states "meandering stream action" while number 2 states "erosion of the stream bed."
While erosion of the stream bed could contribute to the retreat of a waterfall if it is actively undercutting the waterfall's base, the primary factor responsible for waterfall retreat is actually meandering stream action.
When a stream or river meanders, it creates curves in its course, and the water tends to erode the outer edges of these curves, known as cutbanks, while depositing sediment on the inner edges, known as point bars. Over time, the meandering action can cause the waterfall to migrate upstream as the erosion on the outside of the meander bend undermines the downstream section of the waterfall, resulting in its retreat.
Therefore, the correct answer is number 1) meandering stream action.