recurrence interval:
The reciprocal of the annual probability of exceedance of a
hydrologic event (also return period, exceedance interval).
regime:
The condition of a stream or its channel with regard to stability.
A stream is in regime if its channel has reached an equilibrium
form as a result of its flow characteristics. Also, the general
pattern of variation around a mean condition, as in flow regime,
tidal regime, channel regime, sediment regime, etc. (used also
to mean a set of physical characteristics of a river).
regime change:
A change in channel characteristics resulting from such things
as changes in imposed flows, sediment loads, or slope.
regime channel:
Alluvial channel that has attained, more or less, a state of
equilibrium with respect to erosion and deposition.
regime formula:
A formula relating stable alluvial channel dimensions or slope
to discharge and sediment characteristics.
reinforced-earth
A retaining structure consisting of vertical panels and
bulkhead:
attached to reinforcing elements embedded in compacted
backfill for supporting a streambank.
reinforced revetment:
A streambank protection method consisting of a continuous
stone toe-fill along the base of a bank slope with intermittent
fillets of stone placed perpendicular to the toe and extending
back into the natural bank.
relief bridge:
An opening in an embankment on a floodplain to permit
passage of overbank flow.
retard (retarder
A permeable or impermeable linear structure in a channel
structure):
parallel with the bank and usually at the toe of the bank,
intended to reduce flow velocity, induce deposition, or deflect
flow from the bank.
revetment:
Rigid or flexible armor placed to inhibit scour and lateral
erosion. (See bank revetment).
riffle:
A natural, shallow flow area extending across a streambed in
which the surface of flowing water is broken by waves or
ripples. Typically, riffles alternate with pools along the length of
a stream channel.
riparian:
Pertaining to anything connected with or adjacent to the banks
of a stream (corridor, vegetation, zone, etc.).
li
Previous Page
