Environmental Engineering Reference
In-Depth Information
Riparian:
Refers to the interface between freshwater habitats and the terrestrial
landscape.
River in-stream energy systems:
These systems tend to be smaller than their tidal
counterparts; however, many possess similar designs. Unlike tidal facili-
ties, river systems produce electricity only from flows in one direction.
Roller cone bit:
Drill bit that drills by crushing the rock with studded rotating cones
attached to the bit.
Rotten tree:
A live tree of commercial species that does not contain a saw log now
or prospectively primarily because of rot (that is, when rot accounts for
more than 50% of the total cull volume).
Rough tree:
(1) A live tree of commercial species that does not contain a saw log
now or prospectively primarily because of roughness (that is, when sound
cull, due to such factors as poor form, splits, or cracks, accounts for more
than 50% of the total cull volume). (2) A live tree of noncommercial species.
Roundwood:
Wood cut specifically for use as a fuel.
Roundwood products:
Logs and other round timber generated from harvesting
trees for industrial or consumer use.
Run-of-river hydroelectric plant:
A low-head plant using the flow of a stream as it
occurs and having little or no reservoir capacity for storage.
Runoff:
Water from rain, melted snow, or agricultural or landscape irrigation that
flows over a land surface into a water body.
S
Salinity:
A measure of the quantity or concentration of dissolved salts in water.
Salvable dead tree:
A downed or standing dead tree that is considered currently or
potentially merchantable by regional standards.
Saplings:
Live trees 1.0 inch through 4.9 inches d.b.h.
Secondary wood processing mills:
Mills that use primary wood products in the man-
ufacture of finished wood products, such as cabinets, moldings, and furniture.
Seismic:
Pertaining to, of the nature of, or caused by an earthquake or earth vibra-
tion, natural or man-made.
Seismicity:
Refers to the phenomenon of earth movement. Also, the frequency, dis-
tribution, and intensity of earthquakes.
Seismometer:
Electrical device that is used on the surface and within wellbores to
measure the magnitude and direction of seismic events.
Self-potential:
In geothermal systems, a measure of currents induced in the subsur-
face because of the flow of fluids.
Septic tank:
A tank in which the solid matter of continuously flowing sewage is
disintegrated by bacteria.
Sequestration:
Annual net rate at which a tree removes carbon dioxide from the atmo-
sphere through the processes of photosynthesis and respiration (kgCO
2
/tree/
year).
Shade effects:
Impact on residential space heating and cooling (kgCO
2
/tree/year)
from trees located within approximately 15 m (50 ft) of a building (near
trees) so as to directly shade the building.
