Page "Deforestation" Paragraph 22

Shrinking forest cover lessens the landscape's capacity to intercept, retain and transpire precipitation.

Instead of trapping precipitation, which then percolates to groundwater systems, deforested areas become sources of surface water runoff, which moves much faster than subsurface flows.

That quicker transport of surface water can translate into flash flooding and more localized floods than would occur with the forest cover.

Deforestation also contributes to decreased evapotranspiration, which lessens atmospheric moisture which in some cases affects precipitation levels downwind from the deforested area, as water is not recycled to downwind forests, but is lost in runoff and returns directly to the oceans.

According to one study, in deforested north and northwest China, the average annual precipitation decreased by one third between the 1950s and the 1980s.