Streams & Rivers

Mississippi river

Largest US river by discharge & drainage area

Missouri river

Largest US river by length

Amazon river

Largest global river by discharge at mouth

Nile river

Longest global river

Watershed

All land and water bodies in an area that drains into river

Stream Order - Strahler Ordering

Requires 2 streams of the same number to make a larger number

Baseflow

Stream discharge when usual groundwater is only source of water

Perennial

Flows year-round, below water table, base flow

Intermittent

Flows occasionally, at water table, stream water from springs and surface runoff

Ephemeral

Flows occasionally after rain, above water table, surface sources

Floodplain

Land next to stream that is modified by floods that occur less frequently than average flood discharges

Bankfull discharge

Water fills active channel

Wetted channel

Area of wetted stream bed

Heterogeneity of floodplain

Little patches of land separated by water

Channel pattern - straight

Associated with constrained or channelized reaches

Sinuous - meandering

Broad alluvial plains

Sinuous Braided

Always changing, unconstrained reaches

Sinuosity

Measured as thalweg length//valley length

Thalweg

Main thread of flow

Pools

Low gradient, little surface turbulence

Riffles

Moderate gradient, turbulent water

Rapids

High gradient, turbulent

Runs

Slow moving water

Hyporheic zone

Area below water where surface and ground water mix

Parafluvial zone

Subsurface water later of stream

Groundwater exchange

Erosional fronts force water into parafluvial

Embeddedness

degree to which larger particles are buried by finer sediment

Sedimentation

Fine sediment fills interstitial spaces in streambed

Advection

Location of tracer changes

Dispersion

Convention of tracer changes