Water Quality & Management Flashcards
7 cards from real SAF practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Water Quality & Management flashcards as text
Which chemical indicator is most commonly used to assess nutrient enrichment (eutrophication) in forest streams?
Answer: Total nitrogen and total phosphorus concentrations
Total nitrogen and phosphorus are the primary nutrients driving eutrophication, and their concentrations indicate the degree of nutrient enrichment in aquatic systems.
What is the primary advantage of using a macroinvertebrate index to assess stream health compared to chemical testing alone?
Answer: Biological indices integrate water quality conditions over time rather than at a single point
Macroinvertebrate communities reflect cumulative conditions over weeks to months, providing a time-integrated assessment of water quality that spot chemical sampling cannot capture.
In steep terrain, which erosion process poses the greatest threat to water quality following timber harvest?
Answer: Mass wasting events delivering sediment directly to stream channels
Mass wasting (landslides and debris flows) on steep terrain can deliver massive volumes of sediment and woody material directly to stream channels, causing catastrophic water quality impacts.
What does a Total Maximum Daily Load (TMDL) represent under the Clean Water Act?
Answer: The maximum amount of a pollutant a water body can receive while still meeting water quality standards
A TMDL calculates the maximum amount of a pollutant that a water body can receive from all sources while still meeting applicable water quality standards.
Which watershed characteristic most strongly influences the flashiness (rapid rise and fall) of streamflow after rainfall?
Answer: Percentage of impervious or compacted surfaces and soil infiltration capacity
Impervious and compacted surfaces prevent infiltration, causing rapid runoff that produces flashy hydrographs with high peaks and rapid recession.
When designing a culvert for a forest road stream crossing, the pipe diameter should be sized based on:
Answer: The peak flow from a design storm event, typically a 25- to 100-year recurrence interval
Culverts must pass peak flows from design storm events (typically 25- to 100-year recurrence) without causing road overtopping or failure that would release sediment into streams.
After timber harvesting, stream nitrate concentrations typically respond by:
Answer: Increasing as vegetation uptake is reduced and nitrogen mineralization continues
Following harvest, reduced plant uptake combined with continued microbial nitrogen mineralization causes elevated nitrate that leaches into streams, as documented in classic watershed studies like Hubbard Brook.