CESSWI Soil Properties and Site Characterization Flashcards
6 cards from real CESSWI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CESSWI Soil Properties and Site Characterization flashcards as text
Which USDA soil texture class is generally considered the most erodible by water?
Answer: Silt loam
Silt loam soils are highly erodible because silt particles detach easily under raindrop impact and are readily transported by sheet flow.
What does the letter 'D' represent in NRCS Hydrologic Soil Group (HSG) classification?
Answer: Very slow infiltration rate — highest runoff potential
HSG D soils have very slow infiltration rates (typically clay-rich or shallow over impervious layers) and generate the highest surface runoff.
The Universal Soil Loss Equation (USLE) factor 'K' represents what soil property?
Answer: Soil erodibility
The K factor in USLE quantifies a soil's susceptibility to detachment and transport by rainfall and runoff, based on texture, organic matter, and permeability.
A soil with a Unified Soil Classification of 'CH' is best described as:
Answer: Fat clay with high plasticity
In the Unified Soil Classification System, CH denotes fat (high-plasticity) clay, which swells when wet and shrinks when dry, posing stability and erosion challenges.
Which field test is commonly used on a construction site to estimate soil permeability in the field?
Answer: Double-ring infiltrometer test
The double-ring infiltrometer measures the rate at which water infiltrates the soil surface, giving a field estimate of saturated hydraulic conductivity.
On a construction site soil report, a 'dispersion' problem refers to which condition?
Answer: Soil particles that deflocculate in water, making it highly erodible
Dispersive soils have clay particles that repel each other in water, causing the soil to erode internally (piping) or on the surface at very low shear stresses.