CWD Atypical Situations & Problem Wetlands Flashcards

What is a 'problem area' wetland in the context of the 1987 Wetland Delineation Manual?

Answer: A site where standard delineation procedures may lead to incorrect determinations

Problem areas are sites where standard three-parameter procedures may not yield accurate determinations, requiring modified assessment approaches.

How should a delineator approach a site that has been recently drained or ditched?

Answer: Assess pre-disturbance conditions using soil profiles, aerial photos, and hydric soil indicators

For recently drained sites, delineators use soil morphology, historical aerial photography, and hydric indicators to assess pre-disturbance wetland conditions.

What are 'perched water' conditions and why do they create atypical situations for delineators?

Answer: Water held above an impermeable layer that may produce temporary saturation not apparent at the surface

Perched water tables occur above impermeable subsurface layers and can create seasonal saturation that is difficult to detect without monitoring wells or careful soil assessment.

Which tool is most useful for documenting historical wetland conditions in an atypical situation?

Answer: Historical aerial photography

Historical aerial photography can reveal prior wetland conditions before disturbance, filling data gaps in atypical situations where current field indicators are absent.

What is a 'seasonally flooded flat' and why is it considered a problem area for delineation?

Answer: A flat area subject to brief seasonal flooding that may or may not meet wetland hydrology criteria

Seasonally flooded flats have brief or variable inundation making it difficult to determine whether wetland hydrology duration criteria are consistently met.

In prairie pothole regions, what condition creates the greatest difficulty in applying standard delineation methods?

Answer: Extreme wet and dry cycles that obscure normal wetland indicator patterns

Prairie potholes experience boom-and-bust wet/dry cycles driven by climate variability, making hydrology indicators highly variable and difficult to assess in dry years.