Virginia Erosion and Sediment Control
Inspector Exam Questions and 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
groundcover (influenced by humans)
soil properties
topography (influenced by humans)
-What percent reduction occurs from vegetative cover? - -90-99%
-What are soil properties? - -Structure (particles adhere)
Texture (size)
Bulk density (how tightly packed)
% organic matter
infiltration (into soil)
permeability (through soil)
Inspector Exam Questions and 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
groundcover (influenced by humans)
soil properties
topography (influenced by humans)
-What percent reduction occurs from vegetative cover? - -90-99%
-What are soil properties? - -Structure (particles adhere)
Texture (size)
Bulk density (how tightly packed)
% organic matter
infiltration (into soil)
permeability (through soil)
