Over the last millenia, the Northwestern-Alps have been shaped by human land-use, leading to a progressive openess of the landscape. Landscape opening has strongly affected soil erosion intensities and has generalized this threat to all atitudinal zones within this area. Indeed, paleo-environmental records from lake sediment archives revealed the impacts of both intensity and extensivity of agro-pastoralism activities on soil erosion dynamics. Number of sites have faced the exceedance of tolerable erosion thresholds during transient erosion periods conducting to new degraded steady states of erosion conditions compared to the Early-Holocene initial conditions. However, the drivers causing such intensive erosion periods are still barely quantified, limiting our understanding of the impacts of landscape opening on soil erosion and on its related negative feedbacks on the state of the environment. Here we propose to distangle the drivers of long-term soil erosion dynamics by quantifying the respective impacts of both landscape opening and land-use change on soil erosion. We have investigated thousands of scenarios by coupling a soil erosion model and paleo-environmental proxies of land-cover and land-use change to identify the most reaslitic drivers of erosion dynamics in two alpine lake watersheds over the Holocene period. The results suggest the predominance of the impact of extensive patoralism on soil erosion intensity, over even more intensive land-uses like croplands. Moreover, our results suggest the high sensivity of these alpine sites to rapid land-cover disturbances and/or rapid changes in the land-use practices on the erosion response within their respective watershed. Finally, our results further suggest that landscape opening above or below specific land-use intensity thresholds may significatively influence the sensitivity of soil to rainfall. Coupling models and paleo-environmental proxies should hence open new avenues to assess in a more integrative way the drivers of environmental variables within lake watershed systems over long-term periods by permitting quantification, investigation of scenarios and/or testing hypothesis.