Erosion is a natural process by which rock and soil are broken loose from the earth’s surface at one location and moved to another. Soil erosion forms and changes land by wearing down mountains filling valleys, and making rivers appear and disappear. Erosion is usually a slow and gradual process that occurs over the course of thousands or millions of years. However the rate of erosion can be speeded up by such human activities as mining.
How erosion occurs?
Ero0sion begins with a process called weathering. In this process, various environmental factors break rock and soil into smaller pieces and loosen them from the earth’s surface. Other major agents of weathering include chemicals; living organisms; the movement of air, ice, and water; and heat from the sun.
Effects of erosion
Erosion can be both helpful and harmful.it benefits people by contributing to the formation of soil through the breaking up of rock. It causes rich soil to be deposited on the valley floors and at the mouths of rivers. Soil erosion also has produced some of the world’s spectacular geogical formations. One of the most harmful effects of erosion is that it robs farmland of productive topsoil. For this reason it is one of the leading threats to the food supply. Eroded soil can clog irrigation ditches, ponds, and reservoirs.
Although erosion is a natural process, people can influence the extent to which it occurs. Soil erosion increases, for example, when land is cleared and cultivated, because tress and other plants shield soil from wind and rain. Their roots and wastes material from previous plants also help to hold soil in place. Farmers can therefore reduce soil erosion by keeping idle fields planted with such thickly growing cover crops alfalfa or grass. Many farmers also decrease soil erosion through the use of no till and conservation till age techniques, in which wastes from the previous crop remai9n on the soil surface.