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The growing problems of soil erosion and sedimentation due to plantation and construction activities highlight the importance of reliable information on sediment sources with the objectives of designing and implementing targeted management practices. However, reliable information is unavailable for mountainous catchments in southern China. Accordingly, the fingerprinting approach was adopted to quantitatively identify sediment sources in a typical mountainous catchment disturbed by plantation and construction activities in the Dadingshan catchment, Guangdong Province, China. Sensitivity tests were conducted to evaluate the effect of correction factors on the modified model. The results indicated that geochemical elements could be applied for identifying sediment sources within the study catchment. However, the coarse sediment in the catchment posed challenges to the conservative behaviour of tracers. The findings suggested that the primary sediment source is exposed subsoil (51.5 ± 10.0%), followed by plantation topsoil (35.3 ± 16.2%) and wind farms (13.2 ± 10.2%). The mean goodness‐of‐fit value for all sediment samples was 87.1 ± 5.7%. The sediment contributions of various sources varied significantly due to differences in the extent and intensity of human intervention and the main erosion type of each source. Sensitivity analysis revealed that considering the assumption of source normality improved the source apportionment accuracy. However, particle size correction and tracer within‐source variability weighting in the modified mixing model resulted in unusual estimates of the source contributions. This contribution highlights the significance of considering uncertainties in key fingerprinting‐related aspects and emphasizes the need for implementing sediment control strategies in degraded forest environments. [ABSTRACT FROM AUTHOR]

• Impacts of slope shapes on the spatial variation of soil erosion were investigated by using 137Cs. • The relationships between slope shape and soil erosion rates were established. • The soil erosion rate fluctuates with slope length periodically. • The change in the soil erosion rate with slope length in a straight slope shape can be described by the cosine function. • To provide theoretical reference for soil erosion control on sloping farmland with different slope shapes. Slope shape has an important influence on soil erosion. However, the distribution of erosion and deposition on sloping farmland with different shapes is still unclear. This severely restricts the soil loss evaluation and protection of Mollisol resources in northeast China, where sloping farmland (<10°) accounts for 60 % of the cultivated land. In this study, the 137Cs technique combined with wavelet analysis theory was employed to study the spatial distribution characteristics of erosion–deposition rates along three slopes with straight, convex, and concave shapes in northeast China. The results indicated that the average erosion rates of the three slopes were in the following order: convex > straight > concave. The soil erosion and deposition rates fluctuated along the slope length. The primary fluctuation periods in the straight slope, convex slope and concave slope were 45.1 m, 55.0 m, and 40.4 m, respectively. Three relationships of coupled effects of slope gradient and slope length on straight, convex and concave slope were established and verified. It can be concluded that the relationship between the soil erosion rate and slope length was not simple monotonous but showed a certain periodic fluctuation, which was related to the change in transport capacity of runoff on the slope. The change in the erosion–deposition rate with slope length in a straight slope shape can be described by the cosine function. The cumulative soil erosion–deposition rates along the slope had very significant binary power function relationships with both slope length and gradient on convex and concave slopes. The coupled effects of slope gradient and length on soil erosion–deposition for different slope shapes should be fully considered for soil erosion prediction. This study could provide theoretical support for improving erosion prediction models and a scientific basis for the rational arrangement of soil and water conservation measures on slopes at appropriate locations. [ABSTRACT FROM AUTHOR]

[Display omitted] • Compound wind-water erosion was estimated by using 137Cs. • The contributions of wind and water erosion to compound erosion were distinguished. • The water erosion rate was greater than the wind erosion rate on all slopes. Compound erosion is always more intense than singular wind or water erosion in arid and semiarid areas. However, the contribution of different exogenic agencies to compound erosion is difficult to determine. A quantitative study of the proportion of wind and water erosion in compound erosion is necessary to gain insight into and predict compound erosion. In this study, eight slopes with different aspects on a hill were selected in Jingbian County on the Chinese Loess Plateau, which is located in the crisscrossing water-wind erosion region. Compound wind-water erosion was estimated by using 137Cs tracing technology. The contributions of wind and water erosion to compound erosion were distinguished by using two methods, including the revised universal soil loss equation (RUSLE) model and the compound erosion slope divergence characteristics (SDC) method, respectively. The results showed that the northwest windward slope had the highest total erosion rate (76.43 t ha−1 a-1) on all eight slopes with different aspects. The contribution of wind and water erosion to compound erosion partitioned by using the RUSLE model was consistent with that partitioned by using the SDC. The water erosion rate was greater than the wind erosion rate on all slopes. The wind erosion rate was the greatest on the upper part of the northwest slope, which was 27.94 t ha−1 a-1 or 31.38 t ha−1 a-1, as estimated by using SDC method and the RUSLE model and accounted for 36.56 % and 41.06 % of the average annual erosion rate, respectively. The percentage of water erosion was 63.44 % and 58.94 %, respectively. The mutual validation of these two methods provided reliable relative amplitudes of wind and water erosion for compound erosion studies and provided a basis for the quantitative understanding and prediction of compound erosion. [ABSTRACT FROM AUTHOR]