Assessment & Monitoring Methods Flashcards
7 cards from real CSM practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Assessment & Monitoring Methods flashcards as text
A bioassay is used in stormwater assessment programs primarily to evaluate which characteristic?
Answer: Toxicity of stormwater to aquatic organisms
Bioassays use living organisms (e.g., Daphnia, fathead minnow) to assess the acute or chronic toxicity of stormwater or receiving water samples.
In a watershed assessment, what does the term 'effective impervious area' (EIA) represent compared to total impervious area (TIA)?
Answer: Impervious surfaces directly connected to the storm drain system
EIA includes only those impervious surfaces hydraulically connected to the drainage network, which is a better predictor of stormwater runoff volume and stream impacts than TIA.
Which remote sensing tool is most commonly used to delineate impervious surfaces and measure land cover changes in a watershed?
Answer: Satellite or aerial multispectral imagery
Multispectral satellite or aerial imagery allows analysts to classify land cover types, including impervious surfaces, vegetation, and water, across large watershed areas.
A stormwater manager reviews a stage-discharge rating curve for a stream monitoring station. What condition would cause the curve to be unreliable?
Answer: Shifting channel bed due to scour and deposition
A stage-discharge rating curve assumes a stable relationship between water surface elevation and flow; shifting bed conditions alter channel geometry and invalidate the curve.
Which biological indicator is most commonly used to assess stream health impacts from stormwater in the US?
Answer: Benthic macroinvertebrate community index (B-IBI)
Benthic macroinvertebrate index of biotic integrity (B-IBI) scores are widely used because these organisms integrate long-term stream conditions and are sensitive to stormwater-related stressors.
During a dry-weather screening inspection of a storm drain system, what would constitute a potential illicit discharge finding?
Answer: Stormwater flowing in the channel after 72 hours of dry weather
Flow observed at a storm drain outfall more than 72 hours after the last rainfall event is a strong indicator of an illicit non-stormwater discharge connection.
What is the purpose of a 'control watershed' in a paired watershed stormwater study?
Answer: It remains untreated to provide a baseline for comparing changes in the treatment watershed
A control watershed with no management interventions allows researchers to account for natural variation and climate effects when evaluating BMP effectiveness in the paired treatment watershed.