Human activity and related land use change are the primary cause of accelerated soil erosion, which has substantial implications for nutrient and carbon cycling, land productivity and in turn, worldwide socio-economic conditions. Here we present an unprecedentedly high resolution (250 × 250 m) global potential soil erosion model, using a combination of remote sensing, GIS modelling and census data. We challenge the previous annual soil erosion reference values as our estimate, of 35.9 Pg yr−1 of soil eroded in 2012, is at least two times lower. Moreover, we estimate the spatial and temporal effects of land use change between 2001 and 2012 and the potential offset of the global application of conservation practices. Our findings indicate a potential overall increase in global soil erosion driven by cropland expansion. The greatest increases are predicted to occur in Sub-Saharan Africa, South America and Southeast Asia. The least developed economies have been found to experience the highest estimates of soil erosion rates.

Since eroded sediments are produced from different sources distributed throughout a basin, sediment delivery processes at basin scale have to be modelled by a spatially distributed approach. In this paper a new theoretically based relationship is proposed for evaluating the sediment delivery ratio, SDR { , of each morphological unit, i, into which a basin is divided. Then, using the sediment balance equation written for the basin outlet, a relationship between the basin sediment delivery ratio, SDR W and the SDR t is deduced. This relationship is shown to be independent of the soil erosion model used. Finally, a morphological criterion for estimating a coefficient, /3, is proposed. Les processus d'apport de sédiments à l'échelle du bassin versantRésumé Comme les sédiments sont produits dans différentes zones (sources des sédiments) réparties à travers un bassin versant, les processus d'apport de sédiments qui se déroulent dans ce bassin versant doivent être simulés par un modèle mathématique utilisant des données réparties dans l'espace. Dans la présente étude, les auteurs proposent d'abord une nouvelle équation théorique permettant d'estimer le coefficient de production de sédiments SDR ( de chacune des unités morphologiques selon lesquelles le bassin versant a été divisé. Ensuite, en utilisant l'équation de bilan des sédiments relative à l'exutoire du bassin, les auteurs établissent une relation entre le coefficient d'apport de sédiments du bassin versant SDR W et le coefficient SDR { . On peut démontrer que cette relation est indépendante du modèle mathématique utilisé pour estimer l'érosion. Enfin, un critère morphologique est proposé pour estimer un coefficient, (3.

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