Sol erosion is caused by various factors including wind, water and improper land use. In most African countries, it is usually a combination of all these in addition to overgrazing in pastoral areas. Soil erosion is a big problem because when the top rich soil is eroded, agriculture is hindered. This has an adverse effect on the economy, and has led to severe droughts around the world. Read on about this from www.omafra.gov.on.ca/english/engineer/facts/87-040.htm.