a bedload
Mostly By water from river.... than Air, Glaciers etc.
they are deposited by sediment
Sediment deposited by flowing water
Riverbeds are typically made of a combination of soil, sediment, rocks, and other natural materials that have been eroded and transported by the flowing water. The composition of a riverbed can vary depending on factors such as the type of rock in the area, the speed of the water, and the amount of sediment carried by the river.
runoff
Mud in a river forms when sediment, such as sand, silt, and clay, gets eroded from the riverbanks or surrounding areas and gets transported by the flowing water. When the water slows down or the river floods, the sediment settles to the bottom, creating mud.
Sediment that is carried by a stream along the bottom of its channel.
Sediment transported in a stream can cause abrasion by acting as a kind of sandpaper, physically rubbing against and wearing away the surface of rocks and other materials in the stream's bed and banks. The force of the moving water and sediment can increase the rate of abrasion, particularly in areas with high sediment loads or fast-flowing currents. Over time, this abrasion can result in the erosion and shaping of the stream's channel.
This is called erosion. Erosion is the process in which water carries particles of sediment over land, gradually wearing away the surface and transporting the sediment to new locations. This can result in changes to the landscape over time.
An example of a sediment found along a stream is sand. Sand particles are typically larger than silt or clay and are commonly found in streambeds or along the banks of rivers and streams. They are transported by the flowing water and deposited when the flow velocity decreases.
Sediment and runoff are both components of erosion. Sediment refers to the particles of soil and rock that are eroded and transported by water, while runoff is the flow of water over land that can carry sediment and other pollutants. Both sediment and runoff can have detrimental effects on water quality and ecosystems.
Moving water in a river can pick up sediment and carry it along in a suspended load. This includes small particles like silt and clay that are held up and transported within the flow of the water.