In recent years nearly all of organizations concerned in United States and Europe have paid much attention to the application of new techniques and methods to study of soil erosion. American scientists are making effort to develop new general soil loss equation, in which the role of gromorphologist will be more stressed. Many researchers attempt to substitute soil shearing resistance for K factor in USLE. Since the calculated rainfall intensity and kinetic energy of rainfall obtained by existing methods tend to be lower than those of natural rainfall, some researchers try to design more efficient equipment which can be used to make direct measurement of kinetic energy of natural rainfall. Some progress has also been made in studying the relationship between kinetic energy and shape of rainfall drop.Thorough study on the relation of soil crust to soil erosion has become a key link to the forecast of soil erosion. Whether rills are developed or not is another key to estimating the amount of soil erosion on slopes.Establishment of mathematic model for soil erosion has attracted much attention of researchers since 1970's, but unfortunately no important breakthrough has been made upto now.
