1. Weathering and erosion of rocks and soil: As water flows over land, it can break down rocks and soil through processes such as abrasion, hydraulic action, and weathering. The resulting sediment is then carried away by the river.
2. Deposition from glaciers and ice sheets: When glaciers and ice sheets melt, they can release large amounts of sediment into rivers. This sediment can include rocks, boulders, and fine-grained material such as silt and clay.
