The paper is based on suspended sediment yield data from 3763 stations and bed load data from 295 stations. Within plain regions a distinct maximum of erosion and sediment yield occurs in the tropical and subtropical zones. Statistical analysis indicates that the principal factors controlling the zonal distribution of erosion are runoff amount and land cultivation. The latter varies considerably in different natural zones. Topographic and geologic controls on the erosion rates are discussed. For small streams, the influence of zonal factors is less pronounced, and azonal factors (topography, geology) are more important. Taking into consideration all the available data, two principal models of erosion may be suggested: natural and natural-anthropogenic
