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Indirect alterations of rivers Human activities within the drainage basin but outside of the river corridor, such as changes in land cover, that affect inputs to the
river corridor
Instream flow A specified minimum discharge within the active channel
Introduced species Non-native plants and animals accidentally or deliberately
introduced to a river corridor; invasive introduced species are those that dramatically increase in population densities and geographic range after introduction
Lag time The time between a change in a control variable(s) and the response of
some component of the river ecosystem
Legacy effect Historical human alterations that continue to influence river
ecosystems
Legacy sediment Sediment that accumulates within a river corridor as a result of
historical human activities, such as sediment filling the backwater of an abandoned dam
Natural flow regime The characteristics of the hydrograph present prior to intensive human alteration of a watershed; commonly described in terms of magnitude, frequency, duration, timing, and rate of change of flow
Natural (historical) range of variability The temporal variations in specified
river parameters under natural conditions; for example, the range of active channel width through time within a particular river segment, assuming that channel
width will vary in response to variations in water and sediment inputs
Natural sediment regime The characteristics of sediment inputs, transport, and
storage present prior to intensive human alteration of a watershed
Nutrient spiraling Nutrients such as nitrogen and phosphorus are displaced downstream as they complete a cycle through the generalized compartments of water,
particulates, and consumers; spiraling length refers to the downstream distance
required for one complete cycle or, for organic carbon, as the distance between
its entry into the river corridor and its oxidation
Particulate organic matter Organic matter carried in rivers is distinguished by
size as fine particulate organic matter (0.45 μm–1 mm) and coarse particulate
organic matter (>1 mm)
Physical integrity A set of active river processes and landforms such that the river
corridor adjusts to changes in water and sediment inputs within limits of change
defined by societal values
Process domains Spatially discrete portions of a landscape or river network that
are characterized by distinct suites of geomorphic processes
Reference conditions Natural or reference conditions typically refers to the characteristics of the river ecosystem present prior to intensive human manipulation
of the environment within the watershed and the river corridor
Resilience The persistence of the river ecosystem and its ability to absorb external
changes and maintain the same relationships between biological populations or
physical parameters
Resistance The ability of a river ecosystem to resist changes in form and process
caused by disturbance
Glossary
Indirect alterations of rivers Human activities within the drainage basin but outside of the river corridor, such as changes in land cover, that affect inputs to the
river corridor
Instream flow A specified minimum discharge within the active channel
Introduced species Non-native plants and animals accidentally or deliberately
introduced to a river corridor; invasive introduced species are those that dramatically increase in population densities and geographic range after introduction
Lag time The time between a change in a control variable(s) and the response of
some component of the river ecosystem
Legacy effect Historical human alterations that continue to influence river
ecosystems
Legacy sediment Sediment that accumulates within a river corridor as a result of
historical human activities, such as sediment filling the backwater of an abandoned dam
Natural flow regime The characteristics of the hydrograph present prior to intensive human alteration of a watershed; commonly described in terms of magnitude, frequency, duration, timing, and rate of change of flow
Natural (historical) range of variability The temporal variations in specified
river parameters under natural conditions; for example, the range of active channel width through time within a particular river segment, assuming that channel
width will vary in response to variations in water and sediment inputs
Natural sediment regime The characteristics of sediment inputs, transport, and
storage present prior to intensive human alteration of a watershed
Nutrient spiraling Nutrients such as nitrogen and phosphorus are displaced downstream as they complete a cycle through the generalized compartments of water,
particulates, and consumers; spiraling length refers to the downstream distance
required for one complete cycle or, for organic carbon, as the distance between
its entry into the river corridor and its oxidation
Particulate organic matter Organic matter carried in rivers is distinguished by
size as fine particulate organic matter (0.45 μm–1 mm) and coarse particulate
organic matter (>1 mm)
Physical integrity A set of active river processes and landforms such that the river
corridor adjusts to changes in water and sediment inputs within limits of change
defined by societal values
Process domains Spatially discrete portions of a landscape or river network that
are characterized by distinct suites of geomorphic processes
Reference conditions Natural or reference conditions typically refers to the characteristics of the river ecosystem present prior to intensive human manipulation
of the environment within the watershed and the river corridor
Resilience The persistence of the river ecosystem and its ability to absorb external
changes and maintain the same relationships between biological populations or
physical parameters
Resistance The ability of a river ecosystem to resist changes in form and process
caused by disturbance
Glossary