What's the bad landscape effect of more gravel at the bottom of the river?

Affect the landscape effect of the river.

Because the gravel will block the sun, it will have a negative impact on the ecology of fish, thus inhibiting the normal growth of plants at the bottom of the river, thus affecting the landscape effect of the river.

In addition, gravel blocking the depression at the bottom of the river may lead to an increase in the water level at the bottom of the river, causing adverse effects.