What is the process known as when topsoil is removed by wind or water?

The process of topsoil being removed by wind or water is known as soil erosion. This occurs when natural forces, such as wind and water, wear away the soil surface, particularly the fertile top layer, which is essential for plant growth. Soil erosion can happen gradually or as a result of heavy rainfall or strong winds, leading to a loss of nutrients and lower soil quality. By understanding soil erosion, students can appreciate the importance of preventing practices that contribute to this phenomenon, such as deforestation, overgrazing, and poor agricultural methods.

The other options refer to different processes. Desertification involves the degradation of land in arid and semi-arid areas, usually due to climate change and human activities. Pollution pertains to the introduction of harmful substances into the environment, harming both ecosystems and human health. Salinization refers to the accumulation of salts in soil, which can adversely affect plants but does not specifically involve the physical removal of soil. These contextual differences highlight why soil erosion is the most accurate term for the removal of topsoil by wind or water.