SCALES: An Original Model to Diagnose Soil Erosion Hazard and Assess the Impact of Climate Change on Its Evolution

Patrick Le Gouée (1) , Olivier Cantat (1) , Abdelkrim Bensaïd (1) , Alexis Goulet (1) , Daniel Delahaye (1)

1 LETG - Caen - Littoral, Environnement, Télédétection, Géomatique

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 hazard constitute essential documents. 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 temporality when we assessed this hazard. 250 After we proved SCALES was operational in Calvados, we contemplated editing the model in order to achieve an assessment of the erosion hazard within intra-annual time scales. SCALES progressive nature allows us to consider this model as spatially and temporally dynamic. However, the required investment for produce the data in order to decline the model at the monthly and seasonal scales does not allow us to establish a mapping of the soil erosion hazard on a regional level. Consequently, this fine temporal approach must be held for sectors with strong environmental stake. If SCALES can be used in a predictive approach, its structuring and its modularity also give opportunities within a prospective framework. It is what we did, in Basse-Normandie, concerning the topic of the impact of the climate change on the evolution of the cultivated soils susceptibility to erosion by water. In average year at horizon 2100, the results of this new application show that the levels of soil erosion hazard would be comparable with those currently obtained within the one year framework rainy of which the probability of return is once every 4 years. One would thus witness a reinforcement of the soil erosion hazard in average year. We now wish to look further into the prospective application of SCALES starting from the studies which present, in comparable areas, the scenarios of agricultural practices evolution in a near future and a future distance. Our first results and the aim which we propose are altogether in the spirit of the recommendations of the GIEC (2007b) and the European Environment Agency which reminds us the necessity to develop tools to assess the impact of climate change on soils.

Mots clés: Soil; erosion; SCALES; climate change

Domaines: Environnement et Société

Patrick Le Gouée, Olivier Cantat, Abdelkrim Bensaïd, Alexis Goulet, Daniel Delahaye. SCALES: An Original Model to Diagnose Soil Erosion Hazard and Assess the Impact of Climate Change on Its Evolution. Intech. Soil Erosion Studies, Intech, pp.227-252, 2011, 978-953-307-710-9. ⟨10.5772/23501⟩. ⟨hal-00703107⟩