How does vegetation affect interception storage and runoff timing?

How does vegetation affect interception storage and runoff timing?

• A. Vegetation decreases interception storage and accelerates runoff
• B. Vegetation increases interception storage and delays runoff
• C. Vegetation has no effect on interception storage or runoff
• D. Vegetation converts interception storage to surface storage

Answer: (B)

Vegetation stores rain in the canopy and on leaves, branches, and litter as interception storage. That water sits there temporarily, either evaporating back to the air or being released gradually as throughfall, so less rainfall reaches the ground immediately. Because the input to the soil is buffered and released more slowly, the runoff is delayed and the peak discharge is often reduced. In addition, the roughness of vegetation slows surface flow and gives more time for infiltration, further delaying runoff. So vegetation increases interception storage and slows the onset of runoff.

Vegetation stores rain in the canopy and on leaves, branches, and litter as interception storage. That water sits there temporarily, either evaporating back to the air or being released gradually as throughfall, so less rainfall reaches the ground immediately. Because the input to the soil is buffered and released more slowly, the runoff is delayed and the peak discharge is often reduced. In addition, the roughness of vegetation slows surface flow and gives more time for infiltration, further delaying runoff. So vegetation increases interception storage and slows the onset of runoff.