FIGURE 5(a) Landscape before deforestation
Oxygen released by vegetation
Evapotranspiration
Trees protect soil from heavy rain. Leaf litter enriches soil.
Infiltration of water
Water table
Low run-off
Cultivated land
Steady river flow
Tree roots hold soil and maintain a stable water table.
FIGURE 5(b) Landscape after deforestation
Plantation crops
Evapotranspiration decreases.
Reduced infiltration
Grazing
Wind removes topsoil.
Land slippage
Roads destabilise hillsides.
Erosion
Water table rises.
Heavy rain leaches nutrients from topsoil.
Gullies form.
Silt blocks rivers.
TOPIC12 Geographical concepts and skills 269
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