Rivers erode and shape the ground as they flow through it over time.

After this, what is the name for the soil carried down the river, and what is it useful for?

The soil carried down the river is called sediment. Sediment can be made up of different particles and materials such as sand, silt, clay, and organic matter. It is useful for various purposes, including the formation of fertile floodplains, which are agricultural areas with nutrient-rich soil ideal for growing crops. Sediment can also contribute to the replenishment of beaches, deltas, and wetlands, helping to maintain diverse ecosystems and protect coastal areas from erosion. Additionally, sediment can be used in construction, as it provides a resource for making concrete and fill material.