Question

Afforestation help to overcome flood

Answer 1

When trees are taken off, floods often increase because most of the rainwater enters streams and rivers in a very short timeframe. Such high intensity flow is often not usable by human beings and usually flows into the ocean, while also causing soil erosion which leads to loss in soil nutrients. This is why large areas of formerly productive land, where annual rainfall is relatively high, have become desertified once tree cover is removed.

Hope it helps...

Answer 2

Trees help rain seep into soil because living and decaying roots make soil porous by creating a network of well-connected, minuscule channels in the soil. Rainwater seeps into soil with such channels several hundred times faster than it seeps through soil without channels.

Additionally, when plant debris falls on the soil and starts to organically degrade, it helps soil maintain integrity and form small aggregated clumps. These clumps also ensure that soil is porous.

Thus, land under tree cover is more capable of absorbing rainwater. This reduces the volume of water flowing over the surface after a rain event, and thus reduces the volume of water entering rivers and streams. Computational models show that if reforesting is done in 20-35% of the river’s catchment, a 10-15% reduction is seen in flood peak heights after 25 years of forest growth