EROSION is the removal and simultaneous transportation of earth materials from one location to another by water, wind, waves, or moving ice. DEPOSITION is the placing of the eroded material in a new location. All material that is eroded is later deposited in another location.
Erosion and deposition are occurring continually at varying rates over the earth’s surface. Swiftly moving floodwaters cause rapid local erosion as the water carries away earth materials. Deposition occurs where flood waters slow down, pool or lose energy in other ways and the materials settle out. Similarly, wind erosion can occur from exposed areas such as fields, tailings and desert areas when the wind is strong and the materials are deposited when the wind diminishes. Another factor that controls the amount of erosion is the ease with which material can be dislodged. Hard granites erode very slowly while soft silts and sands erode very quickly. Vegetation that holds soils in place can decrease significantly the rates of erosion from water and wind.