The size and complexity of large floodplains result from the hydroclimatic and tectonic settings required to produce large rivers with copious sediment supplies and adequate accommodation space, and also from certain scale-dependent processes. Water and sediment exchanges with the channel determine the construction and preservation of floodplain landforms. The intensity of plant colonization as well as physical and chemical changes to the accumulated sediment, play important roles in stabilizing floodplain sediment, affecting its residence time and geomorphology. These features, together with the time available for the adjustment of tectonic, climatic, or eustatic changes, affect the geometry and behavior of large-river floodplains. © 2013 Elsevier Inc. All rights reserved.