Gravity is the main driving force behind river flow. It pulls water from higher elevations to lower elevations, causing it to flow downhill and form rivers.

Straight river patterns are relatively rare in nature. Rivers typically exhibit meandering, braided, or dendritic patterns due to various factors such as slope, sediment load, and underlying geology.

Erosion is the process by which a river wears away its bed and banks through the action of flowing water and sediment transport.

Clay is not typically considered a river sediment as it is very fine-grained and easily suspended in water. Sand, gravel, and silt are more common types of river sediments.

Deposition is the process by which a river drops its sediment load, typically when the flow velocity decreases. This can occur at various locations along a river, such as the inner banks of meanders, downstream of rapids, or at river deltas.

Climate directly influences river discharge and sediment supply, but it is not a direct factor in shaping river morphology. Slope, sediment load, and underlying geology are the primary factors that determine a river's morphology.

Meandering is the lateral movement of a river channel over time, resulting in a sinuous pattern. It is a common river pattern observed in many parts of the world.

Canyons are typically formed by fluvial processes, but they are not considered riverine landforms. Floodplains, deltas, and meanders are all landforms directly associated with rivers.

Transportation is the process by which a river carries sediment downstream. It occurs through various mechanisms, including bedload transport, suspended load transport, and dissolved load transport.

Groundwater flow is not a type of river discharge. River discharge refers to the volume of water flowing in a river, which is primarily composed of base flow, storm flow, and flood flow.

Thalweg is the term used to describe the longitudinal profile of a river, representing the deepest part of the river channel.

Abrasion is not a type of river erosion. River erosion typically occurs through headward erosion, lateral erosion, and vertical erosion.

Avulsion is the term used to describe the process by which a river's course changes over time, typically involving the abandonment of an existing channel and the formation of a new one.

Forest is not a type of riverine habitat. Riffles, pools, and runs are common riverine habitats that support diverse aquatic life.

Sorting is the process by which a river's sediment load is sorted and deposited based on particle size and density. Finer sediments are typically transported farther downstream, while coarser sediments are deposited closer to the source.