Discussion
Validation of model
results
The CSLE model has been used widely on the Loess Plateau (Kou et al.,
2020; Wei et al., 2021; Wu et al., 2016; Zhang et al., 2020), and
advances in remote sensing data resolution and geographic information
system technology have vastly improved model applicability and accuracy.
Current assessments of soil erosion models typically use measurements
based on field monitoring and isotope tracer techniques, often relying
on depleted radionuclide inventories to simulate medium/long-term soil
redistribution rates. Other remote sensing means use high-resolution
aerial imagery to assess erosion severity in a
qualitative/semi-quantitative manner (Fischer et al., 2018). Due to the
lack of detailed historical field observation data in this study, we
collated the results of published papers in the study area and compared
them to our model results. Huang et al. (2020) used the CSLE model to
assess soil losses in the Jiuyuangou watershed from 1970 to 2015, drew
soil erosion modulus grading maps (1977, 2004, and 2015), and analyzed
the effects of land use and slope on soil erosion. We compared the soil
erosion modulus in 2015 with our results for the slope classification
statistics (Figure 8a), carried out a correlation analysis based on this
comparison, and calculated the correlation coefficient
(R2) and Nash coefficient (NSE) using the previous
data as the verification value. The results of both studies differed for
slopes less than 15° (MRE=68.13%) but were more consistent for slopes
greater than 15° (MRE=10.84%). The difference is acceptable due to the
different calculation methods used for the T factor. In Figure 8b, the
R2 (0.93) and NSE (>0.8) indicate
credible model results. We also compared our results with the soil
erosion assessment conducted by Wang (2018) in the Wuding River Basin
from 2000 to 2014, which reported that weak erosion dominated the
watershed (88.35% of the total watershed area), consistent with this
study.