Soil erosion analysis of human influence on the controlled basin system of check dams in small watersheds of the Loess Plateau, China

An observability–controllability model of periphery (COMP) is presented based on the system theory. A soil erosion analysis approach is deduced based on the COMP and applied to the quantitative analysis of human influence on soil erosion from the controlled area of Check Dam Shipanmao in the hilly and gully region of the Loess Plateau in China. The controlled area of the check dam is regarded as a basin system. The system input, the system state and the system output of the basin system model are determined as the four erosive rainfall indexes (the maximum rainfall intensity in 30 min, the rainfall erosivity, the rainfall amount and the average rainfall intensity), the areas of four measures of soil and water conservation (the dam land area, the terrace area, the woodland area and the grassland area) and the layer amount of sediment deposited behind the check dam, respectively. Compared with traditional methods, the approach presented in this study is more practical and rational. The presented approach has a strong ability of analyzing the change trend of the human influence intensity in the controlled basin system of the check dam.