CEP Field Survey & Data Collection 3 — Questions and Answers
Question 1: When collecting sediment cores from a lake for paleoecological analysis, the primary purpose is to:
- Measure current nutrient loading rates
- Reconstruct historical environmental conditions using proxies (Correct answer)
- Assess benthic macroinvertebrate communities
- Determine current water column stratification
Correct answer: Reconstruct historical environmental conditions using proxies
Sediment cores preserve pollen, diatoms, charcoal, and chemical proxies that allow reconstruction of past vegetation, climate, and disturbance history.
Question 2: A field crew is using a quadrat method to estimate plant species cover. What does a 25% cover estimate in a 1-m² quadrat indicate?
- 25% of plants in the quadrat belong to that species
- The species occupies 0.25 m² of the quadrat's ground surface (Correct answer)
- The species has 25 individual stems per quadrat
- The species canopy is 25 cm tall on average
Correct answer: The species occupies 0.25 m² of the quadrat's ground surface
Cover estimates the proportion of the ground surface (or quadrat area) occupied by the vertical projection of a species' aerial parts.
Question 3: Which type of aerial photography is most useful for identifying surface drainage patterns and subtle topographic features in an environmental survey?
- True-color vertical photography
- Oblique near-infrared photography
- Stereoscopic black-and-white vertical photography (Correct answer)
- Thermal infrared imagery
Correct answer: Stereoscopic black-and-white vertical photography
Stereo pairs of black-and-white vertical photos allow three-dimensional viewing that reveals subtle relief and drainage patterns better than single-image color photos.
Question 4: A field environmental planner observes soil with mottles showing strong brown and gray colors. This most likely indicates:
- High organic matter accumulation
- Periods of seasonal saturation and oxidation-reduction cycling (Correct answer)
- Deep well-drained sandy loam
- Recent alluvial deposition
Correct answer: Periods of seasonal saturation and oxidation-reduction cycling
Mottles (redoximorphic features) of orange/brown iron oxidation and gray iron reduction indicate fluctuating water table and periodic anaerobic conditions.
Question 5: Which data collection approach is best suited for assessing cumulative noise impacts along a proposed highway corridor?
- Single-event spot measurements at one receptor
- Long-term continuous noise monitoring at multiple representative receptors (Correct answer)
- Instantaneous sound level readings during peak traffic only
- Indoor noise measurements with windows closed
Correct answer: Long-term continuous noise monitoring at multiple representative receptors
Cumulative noise assessment requires Leq and Ldn metrics derived from continuous monitoring at representative sensitive receptors over extended periods.
Question 6: When using a flow meter to measure stream discharge, the mid-section method calculates discharge by:
- Multiplying total stream width by average depth and average velocity
- Summing the products of subsection width, depth, and velocity across the cross-section (Correct answer)
- Dividing total flow area by the number of velocity measurements
- Using the Manning equation with channel slope and roughness
Correct answer: Summing the products of subsection width, depth, and velocity across the cross-section
The mid-section method divides the channel into vertical subsections and sums (width × depth × velocity) for each to obtain total discharge.
Question 7: A field team collects ambient air samples using Summa canisters. The primary target analytes for this method are:
- Particulate matter (PM2.5 and PM10)
- Volatile organic compounds (VOCs) (Correct answer)
- Total suspended solids
- Heavy metals in airborne dust
Correct answer: Volatile organic compounds (VOCs)
Summa canisters are evacuated stainless-steel vessels used specifically for collecting and preserving VOC samples per EPA Method TO-14A/TO-15.
CEP Field Survey & Data Collection 3
When collecting sediment cores from a lake for paleoecological analysis, the primary purpose is to: