CF CF Watershed & Soil Conservation 1 — Questions and Answers
Question 1: What is the primary purpose of a best management practice (BMP) related to stream crossings in forestry operations?
- Prevent sediment delivery and protect water quality at stream crossings (Correct answer)
- Maximize log transport efficiency
- Reduce road construction costs
- Increase stream flow velocity
Correct answer: Prevent sediment delivery and protect water quality at stream crossings
Stream crossing BMPs such as properly sized culverts and bridging prevent sediment from entering streams during timber harvesting operations.
Question 2: Which soil property most directly determines a site's susceptibility to compaction from heavy logging equipment?
- Soil texture and moisture content (Correct answer)
- Soil pH
- Cation exchange capacity
- Soil color
Correct answer: Soil texture and moisture content
Fine-textured soils (clay and silt) at high moisture content are most vulnerable to compaction because water reduces inter-particle friction and pore space collapses under load.
Question 3: What is the function of a broad-based dip (BBD) on a forest road?
- Divert surface water off the road surface before it gains erosive velocity (Correct answer)
- Provide a vehicle turnaround area
- Reduce road gradient to legal limits
- Mark the road centerline for navigation
Correct answer: Divert surface water off the road surface before it gains erosive velocity
Broad-based dips are drainage structures built into forest roads that interrupt surface water flow and redirect it into stable vegetated areas before it erodes the roadbed.
Question 4: Which equation is most widely used in the US to estimate annual soil erosion from forest and agricultural land?
- Universal Soil Loss Equation (USLE) (Correct answer)
- Darcy's Law
- Manning's Equation
- Moody Chart
Correct answer: Universal Soil Loss Equation (USLE)
The USLE estimates average annual soil loss as a function of rainfall erosivity, soil erodibility, slope length/steepness, cover management, and support practices.
Question 5: A riparian buffer strip in a harvested watershed primarily reduces which water quality concern?
- Sediment delivery and nutrient loading to streams (Correct answer)
- Stream temperature increase in winter
- Groundwater salinization
- Dissolved oxygen reduction in deep water
Correct answer: Sediment delivery and nutrient loading to streams
Riparian buffers filter overland flow, trapping sediment and retaining nutrients before they reach stream channels.
Question 6: What does 'peak flow' refer to in watershed hydrology?
- The maximum discharge rate in a stream following a storm event (Correct answer)
- Average annual streamflow
- The rate of evapotranspiration from a watershed
- Groundwater table depth
Correct answer: The maximum discharge rate in a stream following a storm event
Peak flow is the highest flow rate observed in a stream during or immediately after a precipitation event and is critical for flood prediction and culvert sizing.
CF CF Watershed & Soil Conservation 1
What is the primary purpose of a best management practice (BMP) related to stream crossings in forestry operations?