Referring to fluvial contexts, processes, and products. The form of an alluvial channel (cut in alluvium) reflects the load and discharge of the river rather than the bedrock. Dade (2000) Geomorph. 35, 1 relates sediment grain size and transport mode to the channel pattern of a river. An alluvial fan is a triangular landform; its shape results from the river swinging back and forth during aggradation while the apex is fixed at the point where the river emerges from the uplands. Arzani (2012) ESPL 37, 7, 726 finds that alluvial fans in Iran developed their geometry mainly in response to different weathering intensities of their catchment bedrock lithologies. See also Pope et al. (2008) Geomorph. 94, 1–2. An alluvial cone, similar in origin, tends to have a steeper slope.

Alluvial filling is sedimentation from fluvial channels. During low water, alluvial flood plains are mostly dry, but when most of the flood plain is swamped, coarse material is transported short distances, temporarily deposited, and picked up during the next flood. Major controls on alluvial flood plains include sediment, flow regime, and differing base levels (O’Connor et al. (2003) Geomorph. 51, 1–3). Alluvium is a general term for deposits laid down by present-day rivers, characterized by sorting (coarser alluvium is found in the upper course of rivers; finer in the lower courses), and stratification (coarse material is overlain by finer). Alluvial landforms include deltas, river beds, and flood plains.