QUESTIONS WITH DETAILED VERIFIED ANSWERS (100%) | ALREADY
GRADED A+
Principles of ESC - Correct Answer -1. Erosion Control
2. Sediment Control
ORDER IS RELEVANT
1st Line of Defense - Correct Answer -Vegetative Eroision Control
- inexpesive
- easy to install
2nd Line of Defense - Correct Answer -Structural Sediment Control
- expensive
- Requires Maintenance
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,Contour Line - Correct Answer -a line on a map connecting points on a land surface that are the same
elevation above sea level
Sheet Flow - Correct Answer -a shallow layer of water flowing more or less uniformly over the land.
Can effectively transport sediment particles kept in suspension from the action of falling raindrops in a
disturbed area.
Concentrated Flow - Correct Answer -A result of the depth of sheet flow and irregularities in the soil
surface (low spots, depressions, rocks, plant stems, roots, etc.).
Runoff starts in tiny rills and then expands into large gullies, aquiring more energy to detach and
transport soil particles.
> water volume = > velocity and turbulence = > soil dislodged
Suspended soil particles strike and abrade the soils surface like sandpaper, causing more soil particles
to detach and mobilize, further increasing abrasive force.
The energy of runoff is a function of? - Correct Answer -- Slope gradient
- Slope length
- Volume of runoff
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,Water Quality Impacts of Runoff and Envronmental Implications - Correct Answer -2nd most prevalent
source of water quality impairment in VA's estuaries (Agriculture is #1)
- sediment shades lower layer of waterway, killing aquatic vegetation, so less oxygen in water creating
death :(
- sediment plugs gills suffocating critters, introduces toxins into bodies of animals
- sediment smothers reefs, oyster beds, spawning beds, etc. when it settles
- economy hurt due to decreased commercial fishing yields
Contour Interval - Correct Answer -the interval between contour lines on a map or the altitude the
interval represents
contour lines close together = small contour interval = steep slope
contour lines further apart = large contour interval = not as steep
Cut and Fill - Correct Answer -the excavating of material in one place and the depositing of it nearby
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, if a contour map runs R to L, an existing line (dashed) to the left of the proposed line (solid) represents a
cut; an existing line to the right of the proposed line represents a fill
Drainage - Correct Answer -always flows perpendicular to contour lines
Valleys and Swales - Correct Answer -a long low area of land, often with a drainage way, river or stream
running through it, which is surrounded by higher ground
represented by contours that point towards higher numbers
Ridge - Correct Answer -a long narrow hilltop or range of hills
represented by contours that point toward lower numbers
Summit - Correct Answer -the highest point or top of something especially a mountain
usually have a spot elevation for the highest point
depression/sinkhole - Correct Answer -a low area in a landscape without a clear drainage way, sinkholes
map drain through an underground system (karst system)
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