**4.4 Discussions**

The climate change which has been observed in Europe from the pre-industrial to the current period resulted in an increase of temperatures in the order of 1°C and in a modification of rainfall distribution: +10% to +40% in Northern Europe during the 20th century and -20% in the South (EEA, 2008). On a world scale, we may not evade a climate warming in the order of 2 to 3°C by 2100 (Séguin, 2010).

Available data of the climate change effects on soils are very insufficient in European countries (EEA, 2008). However, according to some work, It seems that this leads to an

SCALES: An Original Model to Diagnose Soil Erosion Hazard

obtained deserve to be well examined.

hazard constitute essential documents.

temporality when we assessed this hazard.

Mortlock, 1993).

Boardman, 1995).

**5. Conclusions** 

and Assess the Impact of Climate Change on Its Evolution 249

increase of soils sensitiveness to erosion by water in Northern European areas on account of an increase of the rainfall frequency and intensity (Boardman, 1990; Boardman and Favis-

Nevertheless, this increase could be minimized under the influence of a modification of the vegetative cycles in the natural and cultivated areas (Ellis et al., 1990 ; Wheeler et al., 1993). We thus notice a significant progress of phenology in Europe (Séguin, 2010). In addition, a CO 2 multiplication by 2 at the end of the 21st century may lead to a 20 to 30% increase of photosynthesis (Séguin, 2010). The sensitiveness to erosion may even be lowered by

However, it is impossible to foresee the agricultural practices evolution for the 21st century because we know well yet the interactions between climate change and agricultural practices. Besides, agriculture depends on political direction and socio-economic contexts. In these conditions, it is not totally unrealistic to consider the climate change impact on the soils sensitiveness on erosion if we base on the current agricultural practices. This choice may also be justified by the fact that, in Europe, agricultural production systems are characterized by a large geographic stability (Seguin, 2010). In addition, the results we

Our work shows that the increase of erosive pressure on the cultivated soils which is forecast for an average year by 2100 would correspond to a scenario which the current frequency is one out of four. The fragility of cultivated soils may therefore be more important and more continuous over time. Although these results for a normal year are given, we must not forget that the climatic variability in a distant future may have consequences as harmful as the deep-rooted trend. Besides, it should be reminded that two climatically similar years may reach different erosive solutions (Favis-Mortlock and

SCALES model helps to propose high spatial and temporal resolution custom-built scenarios of the climate change impact on the evolution of soils sensibility to erosion by water by 2100. Nevertheless, these data can only be produced on a local scale. However, our work is in the spirit of the European Environment Agency which reminds us the necessity to

Soil erosion is a major and growing cause of soil deterioration in many European countries. The main issue is that we must no longer consider soil as a renewable natural resource. Whatever the scale of intervention, the territorial structures need to have spatially spread information in order to overcome or prevent soil erosion. In this regard, maps of erosion

Our goal was multiple when we developed SCALES model. Firstly, the point was to prove that it was reasonable to foresee a regional scale model and map while we have detailed local scale data. Then, we wanted to limit the model applicability to the European oceanic areas which are marked by a mutual pedoclimatic situation and a territorial dividing into agricultural parcels. Besides, our idea was to consider the soil erosion hazard within these parcels which are area sources: assuming that in this geographic context the erosion is more controlled by agricultural units rather than the environment where they dwell. We eventually had to take into consideration the weight of agricultural practices through their

conservative agricultural practices (Hulme et al., 1993; Zhang et al., 2009)

develop tools to assess the impact of climate change on soils (EEA, 2008).

Fig. 14. Soil erosion hazard for current period and for 2100 at monthly scale.

Fig. 14. Soil erosion hazard for current period and for 2100 at monthly scale.

increase of soils sensitiveness to erosion by water in Northern European areas on account of an increase of the rainfall frequency and intensity (Boardman, 1990; Boardman and Favis-Mortlock, 1993).

Nevertheless, this increase could be minimized under the influence of a modification of the vegetative cycles in the natural and cultivated areas (Ellis et al., 1990 ; Wheeler et al., 1993). We thus notice a significant progress of phenology in Europe (Séguin, 2010). In addition, a CO 2 multiplication by 2 at the end of the 21st century may lead to a 20 to 30% increase of photosynthesis (Séguin, 2010). The sensitiveness to erosion may even be lowered by conservative agricultural practices (Hulme et al., 1993; Zhang et al., 2009)

However, it is impossible to foresee the agricultural practices evolution for the 21st century because we know well yet the interactions between climate change and agricultural practices. Besides, agriculture depends on political direction and socio-economic contexts. In these conditions, it is not totally unrealistic to consider the climate change impact on the soils sensitiveness on erosion if we base on the current agricultural practices. This choice may also be justified by the fact that, in Europe, agricultural production systems are characterized by a large geographic stability (Seguin, 2010). In addition, the results we obtained deserve to be well examined.

Our work shows that the increase of erosive pressure on the cultivated soils which is forecast for an average year by 2100 would correspond to a scenario which the current frequency is one out of four. The fragility of cultivated soils may therefore be more important and more continuous over time. Although these results for a normal year are given, we must not forget that the climatic variability in a distant future may have consequences as harmful as the deep-rooted trend. Besides, it should be reminded that two climatically similar years may reach different erosive solutions (Favis-Mortlock and Boardman, 1995).

SCALES model helps to propose high spatial and temporal resolution custom-built scenarios of the climate change impact on the evolution of soils sensibility to erosion by water by 2100. Nevertheless, these data can only be produced on a local scale. However, our work is in the spirit of the European Environment Agency which reminds us the necessity to develop tools to assess the impact of climate change on soils (EEA, 2008).
