CEPSCI Soil Science and Erosion Fundamentals 2

Question 1

What role does organic matter play in soil erodibility?

Accepted Answer

Organic matter decreases erodibility by improving soil aggregate stability, water-holding capacity, and infiltration

Answer

Organic matter binds soil particles into stable aggregates that resist raindrop impact and runoff, and it improves infiltration, both of which reduce erosion.

Question 2

Which soil horizon is typically most vulnerable to erosion when exposed by construction grading?

Accepted Answer

The B or C horizon subsoils exposed after topsoil stripping

Answer

Subsoil horizons (B and C) typically have poor structure, low organic matter, and high clay content, making them more erodible and difficult to revegetate than topsoil.

Question 3

What is 'soil erodibility' as measured by the K factor in the USLE?

Accepted Answer

The susceptibility of soil to detachment and transport by rainfall and runoff

Answer

The K factor quantifies how easily a specific soil type is detached by rainfall and transported by runoff, integrating texture, structure, organic matter, and permeability.

Question 4

What is the effect of vegetative cover on soil erosion rates?

Accepted Answer

Vegetation dramatically reduces erosion by intercepting rainfall, binding soil with roots, and slowing runoff

Answer

A well-established vegetative cover can reduce erosion by more than 99% compared to bare soil by intercepting raindrop energy, increasing infiltration, and binding soil particles with roots.

Question 5

What is 'gully erosion' and why is it significant on construction sites?

Accepted Answer

Advanced-stage erosion where rills merge into large, deep channels that cannot be crossed by equipment, indicating severe loss of soil

Answer

Gully erosion represents extreme concentration of runoff that has cut deeply into the soil, removing large volumes of material and potentially destabilizing adjacent areas.

CEPSCI - Certified Erosion Prevention and Sediment Control Inspector Practice Test

CEPSCI - Certified Erosion Prevention and Sediment Control Inspector Practice Test

CEPSCI Soil Science and Erosion Fundamentals 2