Modelling hillslope soil profiles using a coupled pedogenesis and landform evolution model

Understanding the dynamic evolution of soil profiles on hillslopes is essential for predicting the soilscape response to future climatic changes. In this study, the evolution of soil profiles under different weathering and soil production functions is examined using the State Space Soil Production and Assessment Model (SSSPAM) pedogenesis modelling framework. Four depth-dependent weathering functions, i.e., the exponential, humped exponential, static reversed exponential and the dynamic reversed exponential weathering functions, were examined. The results demonstrate that, depending on the weathering function, the hillslope evolves through different stages. Feedbacks within the soil profile that alter its structure were also observed, and these, too, varied with the weathering function. These insights highlight that soil profile evolution has major implications for landform development and underscore the complexity of pedogenesis. A thorough understanding and quantification of pedogenesis are critical for improving landscape evolution model predictions.