Page 98 - Science class 4

2. By growing grass and
trees

Grass is a plant which
spreads its roots. It

covers the topsoil and
holds it in such a way that

even the strongest of
winds cannot blow it
away. Trees with long

roots, grown in rows, also
hold the soil together and

prevent soil erosion.

3. By constructing dams and embankments

During flood, rivers wash away a lot of topsoil. To prevent this
damage, strong dams and embankments are built at places where

water strikes against the banks. Dams are built across the rivers to

control the force of flood waters. Walls of rocks and stones built
against the banks are called embankments. When the water flow is

slow, it cannot cause much damage to the soil.

Dams reduce soil erosion