Explanation

Main erosion types: sheet erosion (thin layer of topsoil removed uniformly), rill erosion (small channels form), gully erosion (deep channels that cannot be filled by tillage), and wind erosion.

Gully erosion is severe in southeastern Nigeria, destroying farmland, roads, and buildings. Causes include deforestation, improper drainage, and heavy rainfall on exposed soil.

Prevention: afforestation, terracing, contour plowing, cover crops, and proper drainage. Erosion removes fertile topsoil, reducing agricultural productivity and causing environmental damage.