Multiscale comparison of LS factor calculation methods based on diferent fow direction algorithms in Susa Ancient landscape

Topography (LS factor) is one of the most important controlling factors of soil characteristics and geomorphic processes in the landscape. This study was performed in the Susa Ancient site and aimed to compare the estimation of three diferent LS factor calculation methods in which the catchment area was calculated based on seven types of fow direction algorithms using DEM with fve spatial resolutions. For calculating the LS factor, the catchment area attribute was used to calculate the slope length based on the fow direction. Results showed that the catchment area is an entirely scale-dependent attribute and with decreasing the spatial resolution, the statistical values of catchment area increased. At high spatial resolution, the diferent fow direction algorithms despite the diference in the fow distribution to the neighboring cells, but the catchment area attributes calculated based on them, are statistically slightly diferent. By upscaling, the LS factor values calculated in Boehner and Selige and Moore et al. methods increase, whereas in Desmet and Govers method decrease and this change rate indicates that the LS factors calculated by these three methods have the lowest sensitivity to the slope length. At a same scale, the statistics of LS factors calculated based on diferent fow direction algorithms depicted no considerable diferent. The single fow direction algorithms of Rh and D8 cause to calculate the lowest mean values of LS factors at all spatial resolutions. The diference between frequency distributions of the LS factors calculated by these three methods increases with decreasing spatial resolution. The statistical analysis of this study confrms that estimating the LS factor scale and calculation method are more important than the type of fow direction algorithm.

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Opracowanie rekordu ze środków MNiSW, umowa Nr 461252 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2021)