abney: a handheld level, an instrument for
measuring slopes or heights. |
| angle of repose: the maximum slope or
angle at which a material such as soil or loose rock remains stable.
|
| back slope: the shaped transition area
between the road surface and the undisturbed ground on the uphill side of a
road. |
| bank stability: the ability of stream
banks to withstand the erosive forces of water. Bank stability increases in the
presence of deeply rooted plants. |
| berm: a low earth ledge constructed at
the side of a road to divert the direction of flowing water. |
| buffer strip (also leave strip or
buffer): strip of vegetation left intact along a stream or lake during and
after logging. |
| channel: a waterway that contains
moving water either periodically or continuously. A channel has a definite bed
and banks that confine the water. |
| clinometer: a hand level, an instrument
for measuring slopes or heights. |
| corduroy: logs placed over a wet area
to reinforce the natural root mat for the purpose of minimizing the risk of
settlement or foundation failure. |
| culvert: buried pipe or
structure that allows stream flow or road drainage to pass under a road.
Culverts are often round but can be other shapes as well. |
| cut and fill: construction of a road on
undulating ground that is partly excavated and partly filled. |
| fill slope: deliberate placing of
excavated material elsewhere, and dumping material to create roadbeds.
|
| gabion: a woven wire basket filled with
stones of a size that will not pass through the openings in the basket.
Individual baskets are tied together to form retaining walls and erosion
resistant surfaces. |
| geotextile: any permeable textile
material used with soil, rock or any other geotechnical engineering related
material, as an integral part of a man-made product, structure or system,
usually related to the passage of water. |
| groundwater: that part of the
subsurface water that is in the zone of saturation, including underground
streams. |
| height of instrument: the elevation
difference from viewing lens to the ground. |
| nonpoint-source pollution: pollution
from sources that are not specific, such as areas of timber harvesting, surface
mining, and construction. |
| peat: unconsolidated material
consisting of organic matter accumulated under conditions of excessive
moisture. |
| pool: portion of a stream with reduced
current velocity, often with deeper water than surrounding areas and with a
smoother surface. |
| riprap: layer of large, durable
materials (usually rocks) used to protect a stream bank or lake shore from
erosion; may also refer to the materials used. |
| runoff: the part of precipitation and
snowmelt that reaches streams by flowing over the ground. |
| sediment: fragments of rock, soil, and
organic material transported and deposited in bed by water, wind, or other
natural phenomena. The term can refer to any size of particles but is often
used to indicate only fragments smaller than 6 mm. |
| sediment pond: a hole created to divert
sediment laden water, creating enough residence time to allow the solid
material in suspension to drop out, before it is diverted back into a body of
water. |
| sedimentation: deposition of material
suspended in water or air, usually when the velocity of the transporting medium
drops below the level at which the material can be supported. |
| sidecast: road construction material
that is not used for fill and is pushed to or placed on the down-slope side of
the road. Such material may travel long distances down slope before coming to
rest. To so move such material. |
| silt curtain: filter fabric weighted at
the bottom and attached to a flotation device at the top. A silt curtain is
used to isolate an active construction area within a lake or wetland and
prevent silt-laden water from migrating out of the construction zone.
|
| sinkhole: a natural cavity, a hole worn
by water through a rock along a joint or fracture, commonly found in Karst
(limestone) topography. |
| spur: often a short, dead-end road that
leads to a log landing, usually built to a lower standard than the road it
adjoins. |
| stick: a homemade measuring device of a
fixed length used in the stick method of curve layout. |
| streambank: the part of a stream
channel, when seen in cross-section, that restricts the sideways movement of
water at normal flows. It represents a distinct break in slope from the
streambed. |
| tagline: a line of ribbon tied to
branches of trees or shrubs at eye level. It designates the center line of a
proposed road. |
| tensile force: amount of effort to tear
a specific material. |
| trash rack: a screen of logs or a large
metal grate that is placed in front of the inlet end of a culvert to keep large
woody debris from entering. A trash rack can become a source of
blockage. |
| turnout: a widened space in a road to
allow vehicles to pass one another. |
| water bar: a ditch and hump across a
trail or road tied into the uphill side for the purpose of carrying water
runoff into the vegetation, duff, ditch, or dispersion area so it does not gain
the volume and velocity which causes soil movement and erosion. |
| water table: irregular surface of
contact between the zone of saturation and the zone of aeration. |
| wetland: land transitional between
terrestrial and aquatic systems where the water table is usually at or near the
surface or where shallow water covers the land. A wetland has these three
attributes: (1) a predominance of hydric soils (soils that result from wet
conditions); (2) inundation or saturation by surface water or ground water at a
frequency and duration sufficient to support hydrophytic vegetation (plants
adapted to wet conditions); and (3) under normal circumstances, a prevalence of
hydrophytic vegetation. |
