Virginia Erosion and Sediment Control
Inspector Exam Questions and Correct
Answers
Erosion Impact Area
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?
1000 times more than the average natural soil erosion rate.
20 times more than agricultural land.
What are 4 erosive forces?
wind
water
ice
gravity
, Name and define 5 stages of soil erosion.
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?
Kinetic energy is dependent on rainfall amount/intensity, raindrop diameter, and
raindrop velocity
What are two damaging effects of rainfall impact?
Causes soil compression which reduces infiltration
Mainly occurs in May-Sept which is when disturbance is most active
4 factors influencing erosion
climate
Inspector Exam Questions and Correct
Answers
Erosion Impact Area
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?
1000 times more than the average natural soil erosion rate.
20 times more than agricultural land.
What are 4 erosive forces?
wind
water
ice
gravity
, Name and define 5 stages of soil erosion.
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?
Kinetic energy is dependent on rainfall amount/intensity, raindrop diameter, and
raindrop velocity
What are two damaging effects of rainfall impact?
Causes soil compression which reduces infiltration
Mainly occurs in May-Sept which is when disturbance is most active
4 factors influencing erosion
climate
