CWD Hydrology & Soils 3

Question 1

Which soil texture class retains the most water and is most likely to develop hydric characteristics in a flat landscape?

Accepted Answer

Silty clay

Answer

Silty clay has very fine particles with high surface area and low permeability, retaining water longest and promoting anaerobic conditions.

Question 2

What is 'episaturation' as defined in wetland hydrology?

Accepted Answer

Saturation from above due to perched water on a restrictive layer

Answer

Episaturation occurs when water perches above a restricting layer in the soil profile, saturating the zone above while unsaturated conditions exist below.

Question 3

A soil has a matrix chroma of 1 with 20% distinct mottles of chroma 4. What does this pattern indicate?

Accepted Answer

The soil experiences alternating wet and dry conditions with redox cycling

Answer

Low-chroma matrix with higher-chroma mottles indicates redoximorphic features from cyclic wetting and drying with iron oxidation-reduction.

Question 4

Which USDA soil order is most commonly associated with hydric soils in freshwater wetlands of the eastern United States?

Accepted Answer

Histosols

Answer

Histosols are organic soils formed under prolonged saturation and are the most commonly designated hydric soils in eastern freshwater wetlands.

Question 5

What is the significance of a 'drift line' as a wetland hydrology indicator?

Accepted Answer

It shows debris deposited by receding floodwaters, indicating past inundation

Answer

Drift lines are accumulations of water-transported debris (leaves, sticks, sediment) left behind as floodwaters recede, indicating the extent of recent inundation.

(CWD) Certified Wetland Delineator Practice Test

(CWD) Certified Wetland Delineator Practice Test

CWD Hydrology & Soils 3