Erosion is a common term that has a negative connotation to it. Erosion occurs when the sediment moves from one place to another for one reason or another. One way for erosion is when water causes the sediment to be washed away or down river by force from the flow of the water. It can usually be seen if water moves sediment without being in a river.
However, the water is usually moving in the same path or rut. Another kind of erosion is when sediment is taken out of the soil because a farmer has planted on this same soil for many years. Now, the soil does not contain any nutrients because the plants needed it to grow, so the farmer would have to move.