Floodplain Processes

Floodplain ProcessesFloodplain ProcessesKaren Hall

NC Stream Restoration Institute

North Carolina State University

FloodplainsFloodplains

Floodplains are depositional and erosional areas adjacent to streams where the active channel spills during flood events (bankfull events).

Floodplain FormationFloodplain Formation

Lateral accretionVertical accretion

2001 2003

2004 2005

Floodplain FormationFloodplain Formation

Lateral accretionVertical accretion

Floodplain FunctionsFloodplain Functions

Sediment StorageFloodwater Storage/Peak Flow ModerationGroundwater RechargeChannel Stability/Erosion PreventionWater Quality Habitat

Suspended sediment in coastal waters following period of exceptionally heavy rainfall in the mid-Atlantic states, 1999. (Photo courtesy of ODU 2003)


Sediment StorageFloodwater Storage/ Peak Flow ModerationGroundwater RechargeChannel Stability/Erosion PreventionWater QualityHabitat

Changes in HydrographsChanges in Hydrographs

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10

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0 20 40 60 80

Time (hours)

Stre

am F

low

(cf

s)

Rural

Urban



HydrologicHydrologic CycleCycle







Floodplain Processes

Documents

active channel spills

hydrographs50 stream

flood events bankfull

coastal waters

erosional areas adjacent

photo courtesy of odu

heavy rainfall

midatlantic states