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 stream order classification system is most commonly used in watershed analysis for forestry applications?
Answer: Horton-Strahler ordering system
The Horton-Strahler ordering system assigns numerical orders to stream segments based on tributary junctions and is standard for watershed analysis.
Thermal pollution in streams adjacent to harvested areas is primarily caused by:
Answer: Loss of riparian canopy shade allowing solar radiation to heat water
Removal of riparian canopy exposes stream surfaces to direct solar radiation, causing significant temperature increases that stress cold-water fish species.
What is the recommended minimum width for a riparian buffer zone on perennial streams in most state forestry BMP guidelines?
Answer: 50 feet on each side
Most state BMP guidelines recommend a minimum 50-foot buffer on each side of perennial streams, though wider buffers are recommended on steeper slopes.
The parameter 'biochemical oxygen demand' (BOD) in water quality testing measures:
Answer: The amount of oxygen consumed by microorganisms decomposing organic matter
BOD measures the oxygen consumed by microbial decomposition of organic matter over 5 days at 20°C, indicating the degree of organic pollution in water.
Skid trails should be located to minimize water quality impacts by:
Answer: Following contours or at grades less than 10% with frequent water bars
Contour or low-grade skid trails with water bars prevent concentrated flow and reduce erosion by diverting runoff before it gains velocity.
Which type of stream crossing causes the least aquatic habitat disruption when properly installed?
Answer: Bridge with no in-stream footings
Bridges with no in-stream footings span the entire channel, preserving stream hydrology, fish passage, and aquatic substrate without channel modification.
What is the primary purpose of a water bar on a forest road or skid trail?
Answer: To intercept and divert runoff off the road surface before it gains erosive velocity
Water bars are diagonal drainage structures cut across roads and trails to intercept concentrated runoff and redirect it into vegetated areas before erosion occurs.