SCIENTIA GEOGRAPHICA SINICA ›› 2015, Vol. 35 ›› Issue (11): 1482-1488.doi: 10.13249/j.cnki.sgs.2015.011.1482

• Orginal Article • Previous Articles     Next Articles

The Applicability of LS Factor Value from Different Algorithms in Wohushan Reservior Basin

Gang HU1,2(), Hui SONG1, Xing-jun SHI3, Xu-liang ZHANG1, Hai-yan FANG2   

  1. 1. Department of Geography, Normal College of Qingdao University, Qingdao, Shandong 266071, China
    2. Key Laboratory of Water Cycle & Related Land Surface Processes, Chinese Academy of Sciences, Beijing 100101, China
    3. College of Physics, Qingdao University, Qingdao, Shandong 266071, China
  • Received:2014-06-18 Revised:2014-09-19 Online:2015-11-20 Published:2015-11-20

Abstract:

The Universal Soil Loss Equation (USLE) model and its principal derivative and the Revised Universal Soil Loss Equation (RUSLE) model have been widely used in the past decades. However, the use of USLE and RUSLE has been limited by the inability to generate reliable estimates of the LS factor. Several different LS factor algorithms from the previous studies were briefly summarized in this article and their applicability was evaluated in Wohushan reservoir basin. According to the Agriculture Handbook No. 703 and 537 of US Agriculture Department, the LS-values in McCool's table are the same as the LS algorithms in USLE/RUSLE. Although there is some regional heterogeneity in the specific regional applications for LS calculations, the difference is very limited within a certain slope length and slope gradient. Based on these reasons, the LS-values from McCools are primarily preferred as the reference value. There are four basic LS algorithms which were Remortal, Moore, Desmet and B?hner used to be compared with reference value. In addition, two revised algorithms, i.e. the improved iterative Remortal algorithm and complex algorithm, were presented. The slope-length exponent (m) in the former algorithm was revised from low rill/interrill ratio class to moderate class. The complex algorithm was composed of L-factor and S-factor from different research, of which the latter was from the above mentioned improved algorithm of Remortel and S-factor was made up of S algorithm from McCool and that of Liu BY. In this article, the LS values of the six above algorithms were compared with that of McCools by RMSE (the Root Mean Square Error), the correlation coefficient and the slope of the regression equation. The results indicated that, other than the improved algorithm of Remortel and the complex algorithm, the LS-value obtained by different algorithms are all less than that of reference value. It is also found that the optimal algorithm in the study area is the improved iterative algorithm of Remortel, followed by both the AML program of LS factor from RUSLE Version 4 of Remortel and the complex algorithm. The B?hner’s algorithm could also be used in this area. However, the algorithms from Moore and Desmet were recommended not to use in the study area because of their relatively higher RMSEs and relatively poor correlation coefficients.

Key words: LS factor, Remortel algorithms, Wohushan reservoir, soil erosion model

CLC Number: 

  • S157/TP306