Virginia Erosion and Sediment Control
Inspector Exam fully solved graded A+
Erosion Impact Area - correct answer ✔✔ area of land NOT ASSOCIATED with a current land-
disturbing activity but contributing to sedimentation
How much more soil loss occurs from construction sites versus natural soil erosion rates?
Agricultural land? - correct answer ✔✔ 1000 times more than the average natural soil erosion
rate.
20 times more than agricultural land.
What are 4 erosive forces? - correct answer ✔✔ wind
water
ice
gravity
Name and define 5 stages of soil erosion. - correct answer ✔✔ Raindrop- 90% of total soil
erosion
Sheet- the soils ability to infiltrate water is exceeded and it runs in sheet flow (about 100 ft
before concentrating), how sediment gets transported
Rill- when sheet flow begins to concentrate, velocity and turbulence increase, but easily
repaired
Gully-when rills converge, larger than rill and usually requires heavy equipment to repair
Channel- large volume of water increases the gully, vertical sides are observed or for an existing
streambed when structural integrity is destroyed
, What are the factors of rainfall impact? - correct answer ✔✔ Kinetic energy is dependent on
rainfall amount/intensity, raindrop diameter, and raindrop velocity
What are two damaging effects of rainfall impact? - correct answer ✔✔ Causes soil compression
which reduces infiltration
Mainly occurs in May-Sept which is when disturbance is most active
4 factors influencing erosion - correct answer ✔✔ climate
groundcover (influenced by humans)
soil properties
topography (influenced by humans)
What percent reduction occurs from vegetative cover? - correct answer ✔✔ 90-99%
What are soil properties? - correct answer ✔✔ Structure (particles adhere)
Texture (size)
Bulk density (how tightly packed)
% organic matter
infiltration (into soil)
permeability (through soil)
What is K factor? - correct answer ✔✔ the susceptibility of a particular soil to erosion
developed by permeability, soil texture, soil structure, and organic matter content
low K factor is low erodibility (0-0.23), and high is (0.37 +)
Inspector Exam fully solved graded A+
Erosion Impact Area - correct answer ✔✔ area of land NOT ASSOCIATED with a current land-
disturbing activity but contributing to sedimentation
How much more soil loss occurs from construction sites versus natural soil erosion rates?
Agricultural land? - correct answer ✔✔ 1000 times more than the average natural soil erosion
rate.
20 times more than agricultural land.
What are 4 erosive forces? - correct answer ✔✔ wind
water
ice
gravity
Name and define 5 stages of soil erosion. - correct answer ✔✔ Raindrop- 90% of total soil
erosion
Sheet- the soils ability to infiltrate water is exceeded and it runs in sheet flow (about 100 ft
before concentrating), how sediment gets transported
Rill- when sheet flow begins to concentrate, velocity and turbulence increase, but easily
repaired
Gully-when rills converge, larger than rill and usually requires heavy equipment to repair
Channel- large volume of water increases the gully, vertical sides are observed or for an existing
streambed when structural integrity is destroyed
, What are the factors of rainfall impact? - correct answer ✔✔ Kinetic energy is dependent on
rainfall amount/intensity, raindrop diameter, and raindrop velocity
What are two damaging effects of rainfall impact? - correct answer ✔✔ Causes soil compression
which reduces infiltration
Mainly occurs in May-Sept which is when disturbance is most active
4 factors influencing erosion - correct answer ✔✔ climate
groundcover (influenced by humans)
soil properties
topography (influenced by humans)
What percent reduction occurs from vegetative cover? - correct answer ✔✔ 90-99%
What are soil properties? - correct answer ✔✔ Structure (particles adhere)
Texture (size)
Bulk density (how tightly packed)
% organic matter
infiltration (into soil)
permeability (through soil)
What is K factor? - correct answer ✔✔ the susceptibility of a particular soil to erosion
developed by permeability, soil texture, soil structure, and organic matter content
low K factor is low erodibility (0-0.23), and high is (0.37 +)
