B.F. Bachelor of Forestry Forest Hydrology and Watershed Management 1

Question 1

What is 'interflow' (also called subsurface stormflow) in a forested watershed?

Accepted Answer

Water that moves laterally through the soil above an impeding layer and discharges into a stream during or shortly after rainfall

Answer

Water that evaporates directly from the soil surface during dry periods

Answer

Deep percolation of water into bedrock aquifers

Answer

The portion of precipitation intercepted by the forest canopy

Question 2

Which process describes the uptake of soil water by tree roots and its subsequent release as vapor through leaf stomata?

Accepted Answer

Transpiration

Answer

Infiltration

Answer

Percolation

Answer

Capillary rise

Question 3

What does the term 'evapotranspiration' (ET) represent in a watershed water balance?

Accepted Answer

The combined water loss through soil evaporation and plant transpiration

Answer

The total volume of water stored in the soil at field capacity

Answer

Runoff generated exclusively by snowmelt events

Answer

Streamflow measured at the watershed outlet during dry seasons

Question 4

In the variable source area concept, where does overland flow (saturation excess runoff) most commonly originate in a forested watershed?

Accepted Answer

From saturated areas near streams, seeps, and concave hollows

Answer

From ridge tops and upper slopes where soils are thin

Answer

Uniformly across the entire watershed surface

Answer

Only from recently harvested clear-cut areas

Question 5

What is a 'riparian buffer strip' and why is it important in watershed management?

Accepted Answer

A vegetated zone along stream banks that filters runoff, stabilizes banks, and protects water quality

Answer

A planted windbreak along ridge lines to reduce wind erosion

Answer

A gravel-lined channel designed to increase stream velocity

Answer

A cleared strip of land used to create firebreaks near waterways

Question 6

What is the primary hydrological effect of forest harvesting (clear-cutting) on annual water yield from a watershed?

Accepted Answer

Water yield increases because transpiration losses are greatly reduced

Answer

Water yield decreases because exposed soil absorbs more rain

Answer

Water yield remains unchanged because precipitation is unaffected

Answer

Water yield decreases due to increased surface albedo after harvest