Alluvial fan

An alluvial fan is a fan-shaped deposit of soil and rocks. It forms where a fast-flowing river spreads out over a flat plain. They are usually found in between mountain ranges that are crumbling away. If it rains a lot, the fan area will usually flood.

 Alluvial plain 
An alluvial plain is a mostly flat landform where sediment is deposited over time. The cause is the same: one or more rivers coming from highland regions. A floodplain is  the smaller area over which the rivers flood at a particular period of time, and the alluvial plain is the larger area, where floodplains have shifted over geological time.

Related pages
River delta

References

Other websites

Irrigation in the alluvial fan of Punata, Bolivia
Irrigation in the alluvial fan of Garmsar, Iran
Flood recession cropping in the alluvial fan of Okavango, Botswana
Irrigation in alluvial fans in Baluchistan
Irrigation of alluvial fans 

Category:Geology
Category:Landforms
Category:River deltas