5 Discussion
From the above results, the original SCS-CN method did not exhibit good
calibration and validation performances for the three plots in the XDG
watersheds, it still underestimated multiple soil loss events, and it
also performed poorly when applied to the plots of CBG watershed.
Although Huang et al.(2006) and Huang et al.(2007) method with the
single factor of slope and soil moisture were considered respectively,
could enhance the performance to some extent, the improvement is
limited. Overall, the above three methods did not perform as well as the
proposed method. The superior performance of the proposed method
suggests it can accurately predict runoff for different vegetation using
the optimized (calibration) parameter for the six plots in the XDG and
CBG watersheds. The results also provide some insight into the physical
processes represented by incorporating slope, soil moisture, and storm
duration factors in the proposed method, which eliminated the major
shortcomings of the traditional SCS-CN model.