Desertification refers to the formation of barren land from the arid land due to many factors which could be climatic or anthropogenic. The climate factors include no rainfall, arid conditions, less water and water bodies, overgrazing by animals and many others.
As a result of these factors, the plants die or are unable to hold the soil. This leads to loosening of soil which causes soil erosion. This converts the fertile land into infertile land and the land becomes barren.
