Landscaping compromises for land degradation neutrality: The case of soil erosion in a Mediterranean agricultural landscape

Abstract : Soil erosion is the primary process driving land degradation. Using multiple scales of management to minimize soil erosion is crucial to achieve land degradation neutrality targets within the Sustainable Development Goals agenda. Land management (LM) influences both on-site and off-site erosion on the event-scale and over the long-term. However, each LM differs in effectiveness depending on the temporal scale considered. In order to understand how LM effects internal and external catchment dynamics, we apply LandSoil, a physically based landscape evolution model, to evaluate 7 LM scenarios over long- (30 years) and short-terms (event scale). LM scenarios included changes in land use and/or landscape structure. Under current LM, mean surface soil erosion was similar to 0.69 +/- 39.10(-3) m over 30 years. In contrast, a single extreme event (435 mm/24 h) in January resulted in similar to 0.62 +/- 3.10(-3) In loss and similar to 0.04 +/- 2.10(-3) m if it occurred in October. Heterogeneous patterns of erosion and deposition developed after 30 years, whereas extreme events dominantly showed soil loss and high catchment connectivity. Effectiveness of LM in erosion mitigation and sediment trapping differed according to temporal and spatial scales for each scenario. We concluded that multiple temporal and spatial scales must be incorporated in order to adaptively manage land degradation and meet neutrality targets.