How does deforestation cause flooding and droughts?
In recent years countries in the dry tropics have had worsening droughts, alternating with devastating floods. Forests control the run-off of rivers; typically 95 percent of rain reaching the ground is trapped in the soil by virtue of the elaborate spongelike network of roots in the forest floor, and then released slowly through the dry months When the trees are destroyed and the roots die, the soil dries and cracks in the hot sun, and water rushes off the land.Massive flooding results and precious top soil is washed into rivers. Tropical forests can receive in an hour as much rain as London expects in a wet month, and a single storm on deforested land has been found to remove 185 tonnes of topsoil per hectare. In February 1988, 300 people died in mudslides in Rio de Janeiro, Brazil, as a direct result of deforestation. In Thailand in 1988, 450 people died and property valued at $400 million was damaged following indiscriminate commercial logging. In 1978 in India a flash flood inundat
