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• Anticlockwise hysteresis type was the dominating hysteresis type. • Complex hysteresis type generated more sediment than either of three other types. • Antecedent rainfall dominated clockwise type, along with time lag for complex type. • Intraday rainfall and sediment separately dominated clockwise and anti-clock types. • Largest patch index and grassland separately dominated complex and other types. This study aims to quantitatively evaluate the effects of hydrological and landscape characteristics on suspended sediment concentration and discharge (SSC-Q) hysteresis. Runoff and sediment data of 405 flood events were collected from 10 basins in Wudinghe River basin on the Loess Plateau of China. Hysteresis analysis is a key tool for the interrogation of transport of sediment, which have been shown to be important within catchments. It can provide insight into catchment function, allowing the development and testing of process-based hypotheses. The principal components and corresponding explanatory power were extracted quantitatively from hydrological and landscape characteristics via principal component analysis (PCA) and redundancy analysis (RDA), respectively. The most common hysteresis type was anticlockwise. The proportions of the total event sediment loads for different hysteresis types were not always generally correlated to the frequency of the corresponding events. Furthermore, the composition and explanatory power of controlling principal components varied among clockwise, anticlockwise, figure-of-eight, and complex hysteresis types. For hydrological principal components, the antecedent precipitation, intraday precipitation, and sediment principal components controlled clockwise, anticlockwise, and figure-of-eight hysteresis types, which had explained 47.03%, 58.82% and 52.05% of the variation of hysteresis index, respectively; the antecedent precipitation and time lag principal component controlled complex hysteresis type and accounted for 28.22% and 34.65% of the variation of hysteresis index, respectively. For landscape principal components, grassland principal component dominated clockwise, anticlockwise, and figure-of-eight hysteresis types, and accounted for 95.00%, 69.70%, and 92.00% of the variation of hysteresis index, respectively. Largest patch index principal component controlled complex hysteresis type and accounted for 100% of the variation of hysteresis index. Therefore, within this catchment, whereas hysteresis patterns varied due to all of the hydrological and landscape variables to some extent, precipitation, suspended sediment, area of grassland, and the largest patch area had stronger impact on hysteresis dynamics. [ABSTRACT FROM AUTHOR]

Although soil erosion and land use change have long been focuses in carbon research, the combined influence of soil erosion and vegetation rehabilitation on aggregate stability and the associated soil organic carbon (SOC) and total nitrogen (TN) remains unclear. The current study evaluated the effects of soil erosion on aggregate stability and the associated SOC and TN dynamics in relation to vegetation rehabilitation after the implementation of the “Grain-for-Green” project in the hilly Loess region. A check dam sediment sequence was dated using 137 Cs activity and erosive rainfall events. The SOC and TN in the bulk soil and aggregate fractions were measured in soils from rehabilitated grasslands and sloping croplands and in sediments retained by the check dam. The results showed that vegetation rehabilitation led to 78%, 27% and 9% average increases in the macroaggregate amount, mean weight diameter (MWD) and mean geometric diameter (MGD), respectively. In addition, rehabilitation resulted in the highest SOC and TN concentrations and contents in macroaggregates among all the aggregate size fractions. Soil erosion facilitated the modification of the aggregate size distributions along with soil mineralization and induced the incorporation of deeper SOC-poor soils during transport. These processes resulted in the aggregate-associated SOC and TN concentrations and contents in the sediments being significantly lower than those in the eroding sloping cropland soils. The highest reductions were found in microaggregates, which exhibited decreases of 48% and 44% for SOC and TN, respectively. Moreover, reaggregation and gully soils incorporated during soil erosion led to higher values of macroaggregate amount and aggregate stability at depositional sites than those at eroding sloping cropland sites in this study. Our study contributes to the understanding of the effects of soil erosion and vegetation rehabilitation on SOC and TN dynamics, which is crucial for understanding the restoration efficiency in soil erosion control and ecosystem security evaluation. [ABSTRACT FROM AUTHOR]

• Splash erosion affected the redistribution of soil particles and SIC. • The redistribution of splashed material and SIC varied with soil type. • SIC had sorting and enrichment characteristics. Splash erosion caused by raindrops is the first stage of water erosion that detaches and transports soil particles. As an important component of soil particles, soil inorganic carbon (SIC) contains little information on its redistribution during splash erosion. In this study, two soils, purple soil and loess, were selected and placed in a soil tray with a diameter of 20 cm at the center of a splash tray, and a rainfall simulator was used to simulate three raindrop energies in experiments to investigate the migration of soil particles and SIC. The results showed differences in the amount and selective migration of splashed material between the soils, which was evident in the obvious sorting of the particle size of purple soil with distance and the insignificant change of loess soil. The SIC sorting characteristic performed differently in the two soils, that is, the SIC content of purple soil increased with particle size, while that of loess was the opposite. The enrichment and depletion of SIC during splash erosion varied with soil type, and differed from the general enrichment of soil organic carbon (SOC). The SIC enrichment ratio (ER IC) of purple soil was generally > 1, whereas the ER IC values of loess were < 1. In addition, multiple linear regression (MLR) models were established to predict the SIC content of splashed material. Rainfall splash plays an important role in SIC migration and may further affect the carbon cycle. These preliminary results provide a basis for further study of SIC response to rainfall splash. [ABSTRACT FROM AUTHOR]