Agricultural/Bioengineering Soil and Water Conservation Engineering 2 — Questions and Answers
Question 1: Which dimensionless number is used to predict whether channel flow is laminar or turbulent?
- Froude number
- Reynolds number (Correct answer)
- Manning number
- Weber number
Correct answer: Reynolds number
The Reynolds number compares inertial forces to viscous forces and determines the flow regime.
Question 2: In terracing, the term 'terrace interval' refers to:
- Width of the terrace channel
- Vertical or horizontal distance between consecutive terraces (Correct answer)
- Slope gradient of the terrace ridge
- Spacing between drain outlets
Correct answer: Vertical or horizontal distance between consecutive terraces
Terrace interval is the vertical or horizontal spacing between adjacent terraces on a slope.
Question 3: The SCS curve number method is used to estimate:
- Evapotranspiration
- Direct runoff from rainfall (Correct answer)
- Groundwater recharge
- Soil organic matter loss
Correct answer: Direct runoff from rainfall
The SCS (now NRCS) curve number method relates rainfall to direct runoff based on land use and soil type.
Question 4: Which soil texture has the greatest water-holding capacity?
- Sandy soil
- Loamy soil
- Clay soil (Correct answer)
- Gravelly soil
Correct answer: Clay soil
Clay soils have fine particles with large total surface area and small pore spaces, enabling high water retention.
Question 5: Check dams are installed in gullies primarily to:
- Increase stream velocity
- Trap sediment and reduce gully head advance (Correct answer)
- Provide irrigation water storage
- Aerate the soil profile
Correct answer: Trap sediment and reduce gully head advance
Check dams reduce flow energy, trap sediment, and slow the upstream advance of gully erosion.
Question 6: The Penman-Monteith equation is used to calculate:
- Soil bulk density
- Reference evapotranspiration (Correct answer)
- Hydraulic conductivity
- Sediment transport capacity
Correct answer: Reference evapotranspiration
The Penman-Monteith equation combines energy balance and aerodynamic factors to estimate reference ET.
Agricultural/Bioengineering Soil and Water Conservation Engineering 2
Which dimensionless number is used to predict whether channel flow is laminar or turbulent?