Flood pulse concept

[1] The annual flood pulse is the most important aspect and the most biologically productive feature of a river's ecosystem.

This pulse of water is the primary driver of high productivity and decomposition rates as it moves nutrients in and out of the system and is good breeding ground for many species of estuarial organisms.

[6] When the water starts receding, the moving littoral reverses, concentrating nutrients and contributing to phytoplankton growth.

Flood plain systems also serve as migration routes, hibernation spots, and spawning locations for many species.

River floodplain systems can be both natural and man-made; the latter occur when dams and levees create a flood plain.

Through ecosystem alterations such as dams, debris removal, channelization, levees, navigation, irrigation, contamination, logging, fire suppression, species introduction, and agricultural runoff, humans have contributed to the destruction of wetlands and the extinction of species.

[4][5] The flood pulse concept is one of three primary models describing large river ecosystems.

Ganges River Delta
The Ganges River Delta, the largest intertidal delta in the world, is an example of river system exhibiting lentic and lotic characteristics that can be described by the flood pulse concept. As seen in this photograph, the tributaries and distributaries of the Ganges and Brahmaputra Rivers deposit huge amounts of silt and clay that create a shifting maze of waterways and islands in the Bay of Bengal .