CONCLUSIONS

In this study, the SWAT model was successfully applied to a Mediterranean watershed in south Portugal in areas under desertification risk to evaluate the effect of the current land management (BAU) on SE rates under present and future climatic scenarios. SE susceptibility maps allowed to appreciate the role played by a combination of relevant factors in determining SE rate, highlighting the suitability of SWAT model as a valid tool for simulating the impacts of climate variability on streamflow and sediment load and for creating extremely useful tool of land management for expert and not experts of the land management sector. Overall, our data show that future CC in the study area will create on average drier and warmer conditions with a slight increase in extreme events which will result in a very variable spatial distribution of areas under different SE risk, going from areas were SE will diminish compared to the actual climatic conditions and areas where the problem will further increase. The fact that the majority of these areas is currently under managed land cover, requires immediate attention ad adequate measures. This kind of tool might be of great help to inform and raise awareness in farmers, animal breeders and land owner. Results also underlined that, although the changing climate might exacerbate the conditions in the areas more at risk, in several areas of the basin SE rates with the actual conditions are already beyond the recommended threshold to maintain a sustainable equilibrium between soil formation and soil loss, posing serious risk of desertification in the near future.
Supplementary materials . Supplementary information related to the article is given in the following supplementary file (to be added by the journal).
Author contributions . The idea of the work was conceived by Gianluigi Busico, Micòl Mastrocicco and Simona Castaldi, the data processing was made by Gianluigi Busico, Silvia C.P. Calvalho and Eleonora Grilli. The original draft was produced by Gianluigi Busico and while the quality data control was made by Eleonora Grilli and Silvia C.P. Calvalho. Final review, visualization and writing were completed by Micòl Mastrocicco and Simona Castaldi.
Competing interests . The authors declare that they have no conflicts of interest.