Towards estimates of future rainfall erosivity in Europe based on REDES and WorldClim datasets
The policy requests to develop trends in soil erosion changes can be responded developing modelling scenarios of the two most dynamic factors in soil erosion, i.e. rainfall erosivity and land cover change. The recently developed Rainfall Erosivity Database at European Scale (REDES) and a statistical approach used to spatially interpolate rainfall erosivity data have the potential to become useful knowledge to predict future rainfall erosivity based on climate scenarios. The use of a thorough statistical modelling approach (Gaussian Process Regression), with the selection of the most appropriate covariates (monthly precipitation, temperature datasets and bioclimatic layers), allowed to predict the rainfall erosivity based on climate change scenarios. The mean rainfall erosivity for the European Union and Switzerland is projected to be 857 MJ mm ha−1 h−1 yr−1 till 2050 showing a relative increase of 18% compared to baseline data (2010). The changes are heterogeneous in the European continent depending on the future projections of most erosive months (hot period: April–September). The output results report a pan-European projection of future rainfall erosivity taking into account the uncertainties of the climatic models.
- Rainfall erosivity in Europe & Switzerland is estimated to increase by 18% in 2050.
- Rainfall erosivity will increase in 81% of the study area and decrease in the rest.
- R-factor projections include the uncertainty of climatic models.
- Highest R-factor increase is projected in Northern & Central Europe.
- Erosivity is a driver for soil erosion, floods, natural hazards & land use change.
The objective of this study is to estimate the expected change in rainfall erosivity and its impact on soil erosion in Europe during the first half of the 21st century based on the updated IPCC climate change scenarios This study focuses on the R-factor changes without considering the impact of climate change on land/ vegetation cover. Compared to previous studies that used approximation equation based on annual (or monthly) precipitation, this study use as input the high-temporal-resolution Rainfall Erosivity Database at European Scale (REDES) and climatic data derived from the WorldClim database, which is set of global climate grids with a spatial resolution of about 1 km2.
The overall increase of rainfall erosivity in Europe by 18% until 2050 are in line with projected increases of 17% for the U.S.A. The predicted R-factor dataset can be used for applying climate change scenarios in soil erosion models. The predicted mean increase in R-factor is expected also to increase the threat of soil erosion in Europe. However, climate change might substantially affect land cover and land use, which might counterbalance or enhance some erosional trends. In order to predict soil erosion trends in the future these feedbacks between rainfall erosivity and land use/land cover need to be considered. The most prominent increases of R-factors are predicted for North-Central Europe, the English Channel, The Netherlands and Northern France. On the contrary, parts of the Mediterranean basin show a decrease of rainfall erosivity.
The authors found that erosivity will decrease in the Mediterranean (less rainfall) and increase in Central & Northern Europe (more summer storms).