Local Sensitivity Analysis of the LandSoil Erosion Model Applied to a Virtual Catchment

Abstract In this study, we assessed the sensitivity analysis of the LandSoil model (Ciampalini et al., 2012), a landscape evolution model simulating soil erosion at fine spatial resolution (1–10 m) and midterm temporal scales (10–100 years). Our aim was to determine the most significant variables in the model and identify the crucial parameter combinations through their interaction. The methodology we adopted consists of a local sensitivity analysis, also termed “one-factor-at-a-time,” calculating soil loss on a topographical entity—a virtual hillslope—inspired by the virtual catchment framework proposed by Cheviron et al. (2010, 2011). Afterward, a multicategory analysis was set to control the effects and hierarchy of hydrological factors, soil-terrain parameters, and the main topographical configurations of the catchment (i.e., hillslope profile). The results show the classical predominant relevance of rainfall amount (no rain means no water erosion). In a second level, the results highlight the interactions between parameters such as soil roughness, soil crusting, and soil cover responsible for sediment production function, and the influence of the topography describing water flow at the catchment scale.