CWD CWD Atypical Situations & Problem Wetlands 2 — Questions and Answers
Question 1: What is a 'problem area' wetland in the context of the 1987 Wetland Delineation Manual?
- A wetland located within a protected conservation area
- A site where standard delineation procedures may lead to incorrect determinations (Correct answer)
- A wetland that is physically difficult to access
- A site with elevated pollutant concentrations
Correct 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.
Question 2: How should a delineator approach a site that has been recently drained or ditched?
- Classify it as upland automatically due to lack of standing water
- Assess pre-disturbance conditions using soil profiles, aerial photos, and hydric soil indicators (Correct answer)
- Apply only vegetation criteria since soils are disturbed
- Defer entirely to the state agency for determination
Correct 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.
Question 3: What are 'perched water' conditions and why do they create atypical situations for delineators?
- Water held above an impermeable layer that may produce temporary saturation not apparent at the surface (Correct answer)
- Water found only in elevated mountain wetland systems
- Groundwater contaminated by surface runoff pollutants
- Tidal water that occurs above mean high tide elevation
Correct 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.
Question 4: Which tool is most useful for documenting historical wetland conditions in an atypical situation?
- Soil pH meter readings
- Historical aerial photography (Correct answer)
- GPS coordinate data
- Canopy densiometer readings
Correct 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.
Question 5: What is a 'seasonally flooded flat' and why is it considered a problem area for delineation?
- A permanently flooded area with stable year-round water levels
- A flat area subject to brief seasonal flooding that may or may not meet wetland hydrology criteria (Correct answer)
- A coastal area flooded only during major storm events
- A farmed field with year-round irrigation applied
Correct 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.
Question 6: In prairie pothole regions, what condition creates the greatest difficulty in applying standard delineation methods?
- Absence of any recognizable soil horizons
- Extreme wet and dry cycles that obscure normal wetland indicator patterns (Correct answer)
- Permanent deep water with no emergent or aquatic vegetation
- Exclusively upland soil types throughout the landscape
Correct 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.
CWD CWD Atypical Situations & Problem Wetlands 2
What is a 'problem area' wetland in the context of the 1987 Wetland Delineation Manual?