Site Features:

Glossary

1. 7Q10 flow: the lowest average flow for 7 consecutive days which statistically occurs once every 10 years. Please refer to Minimum Instream Flow.
2. Conservation flows:
3. Cover: areas of shelter in the stream channel that provide aquatic organisms protection against predators and a place to rest and conserve energy by providing a reduction in velocity or visability. Examples are logs, undercut banks, boulders, vegetation, etc.
4. Depth: the vertical distance from a point on the stream bed to the water surface.
5. Discharge: volume of water passing through a stream cross-section per unit of time.
6. Fishery: apopulation of fish preferred by anglers.
7. Fluvial generalist: an aquatic species that can use a wide habitat range of depths and velocities.
8. Fluvial specialist: an aquatic species that occupies a narrow habitat range of water depth and velocity; these species are most likely impacted by changes in instream flow.
9. Guilds: agroup of species/life-stages that use similar areas (similar depth, velocity, substrate, cover, and temperature) for spawning, foraging, or refuge across time and space.
10. Habitat suitability curves: graphical description of how a species responds to changes in a habitat characteristic.
11. Mainstem: the main channel of a river system; all tributaries flow into it.
12. Mesohabitat: a section of stream that has similar depth and velocity within a reach. Examples are pools (deep and slow), riffles (shallow, fast), and runs (intermediate).
13. Minimum Instream Flow (MIF): the lowest stream flow required to protect some specified aquatic function; usually defined as the 7Q10 flow, which is less than optimal for aquatic organisms and processes. This is a legal term, not a biological one, and is the basis for issuing water permits in many states.
14. Pocket Run: unique mesohabitat of the North Fork Shenandoah; shallow areas of bedrock interspersed with deeper holes (pockets).
15. Pool: deep, slow current habitats with a concave bedform.
16. Riffle: shallow rapids, with turbulent flow; water surface is broken by substrate that is wholly or partially submerged; convex bedform.
17. Reach: a section of stream with all the mesohabitats present in a segment (see segment); usually 10-15x the average stream width.
18. Run: flat bedform with shallow depth; slightly turbulent flow; water surface is not broken by the bed substrate
19. Spatial: of or pertaining to space; a geographic location; has length, width, and depth.
20. Substrate: physical composition of the stream bottom (silt, sand, gravel, cobble, etc.).
21. Temporal: of or pertaining to time; a period of time.
22. Upper thermal limits: the threshold at which a species cannot survive for an extended period at greater temperatures.
23. Usable habitat: areas of stream in which a species can maintain itself for an extended period.
24. Velocity: distance water moves per unit time (i.e. feet per second).
25. Velocity shelter: physical habitat that provides refuge (i.e. eddies) from high velocity water.
26. Water quality: physical and chemical characteristics of the water like temperature, acidity (pH), and dissolved oxygen (DO).