Water Soil Erosion Evaluation in a Small Alpine Catchment Located in Northern Italy: Potential Effects of Climate Change

Abstract

Water erosion and evaluation of the average annual soil loss considering the potential effects of climate change are the focus of this study, based on the application of two empirical models, the RUSLE (Revised Universal Soil Loss Equation) and the EPM (Erosion Potential Method), to an Italian case study. A small mountain basin, the Guerna creek watershed, is located in the Central Southern Alps (Lombardy, Southern Alps, Bergamo), and it has been affected in the past by flooding and erosion events, which stressed the hydraulic weaknesses of the study area. Three different future climate scenarios were built for the middle of this century (from 2041 to 2060) on the basis of CORDEX data and Representative Concentration Pathways (RCP) set by the IPCC (Intergovernmental Panel on Climate Change) future scenarios: RCP 2.6, RCP 4.5, and RCP 8.5. As concerns climate, precipitation and air temperature are the variables used in the empirical models. On the other hand, potential effects on land use were also considered. Computed soil loss of 87 t/ha/year and 29.3 t/ha/year was achieved using the RUSLE equation and EPM method respectively, without considering the potential effects of climate change. The results achieved showed that climate change impacts on water erosion may not be negligible even by the middle of the current century (the annual average soil loss could change by 6–10% on a basin scale), and a major role is being played by seasonality in rainfall peak intensity.

Keywords

• water erosion
• soil loss
• climate change
• empirical models
• RUSLE
• EPM