Rivers are strong forces that change the land around them. They mainly do this through two main activities: erosion and deposition. Let’s break these down into simpler terms.

Erosion

As rivers move, they have energy that wears away the land next to them. This happens in a few ways:

1. Hydraulic Action: The rush of water can knock loose dirt and rocks from the riverbanks.
2. Abrasion: Tiny bits of rock and sand that the river carries hit against the banks and the riverbed, slowly wearing them away.
3. Attrition: Rocks and pebbles bump into each other, making them smaller and smoother.

For example, rivers can cut through mountains, forming deep valleys that look like a V shape in their early stages.

Deposition

When a river slows down, it starts to drop off the dirt and rocks it has been carrying. This can happen when:

1. The river’s speed decreases: This can occur at bends in the river or when it meets a larger body of water.
2. It has less sediment to carry: After heavy rain, rivers might drop some of the extra dirt and rocks they have.

Some places formed by deposition include:

• Alluvial fans: These form where a river spreads out from a narrow area onto flat land.
• Deltas: These are found where rivers end, and they build up dirt to make new land.

Both erosion and deposition are important for shaping the land, creating many different features that we see in nature.