Question

which of the following changes to the local hydrologic cycle will result if large areas of land experienced clear - cutting?
a transpiration of water from vegetation will increase.
b evaporation of water from the soil will increase.
c runoff from watersheds will decrease.
d siltation of local streams will decrease.

Explanation:

• Option A: Clear - cutting removes vegetation. Transpiration is the process by which water is lost from plants. With fewer plants, transpiration will decrease, not increase.
• Option B: When there is clear - cutting, the soil is more exposed. Sunlight can reach the soil more directly, and there is less canopy cover to block wind. These factors lead to an increase in the evaporation of water from the soil.
• Option C: Clear - cutting reduces the ability of the land to absorb water (since there are fewer roots and less vegetation to slow down water infiltration). This results in an increase in runoff, not a decrease.
• Option D: Clear - cutting can lead to soil erosion. As the soil is eroded, more sediment (silt) is carried into local streams, increasing siltation, not decreasing it.

Answer:

B. Evaporation of water from the soil will increase.