While the resilience of French vineyards is currently threatened, this paper focuses on the Beaujolais terroir, where the disappearance of vineyards has been qualitatively observed by local stakeholders. A targeted survey was led at three complementary scales. First, we provide an overview of the evolution of agricultural landscapes and practices for the whole Beaujolais area since 1990 from national statistical databases. It shows that the vineyard extent reached a maximum during the 1990s and that significant bifurcation occurred in 2000. Second, we document land use evolution in relation to vineyard abandonment at a more local scale. Three case studies (lower Ardières, Marverand, Merloux) exemplify the main local settings, and the land uses are described over time from an analysis that employed multitemporal photo interpretation. The results quantified the decrease in the vineyard surface extent since 1999: approximately 30% was lost in regular terroirs and 5% was lost in high added-value terroirs. Third, at a fine scale, we explained the precise location of the abandoned parcels regarding the site characteristics (e.g., incoming solar radiation, slope gradient, terroir quality). The results showed differences in evolution patterns between southern and northern Beaujolais. In northern Beaujolais, winegrowers tended to abandon vine parcels that were considered of lower quality; while, in southern Beaujolais, the winegrowers tended to abandon vine parcels in relation to the difficulty of maintenance (remote and steep parcels were preferentially abandoned) or in relation to suburbanization (parcels close to built-up areas were preferentially abandoned).

Le Beaujolais est un vignoble en crise économique depuis la fin des années 1990. Elle se matérialise dans les paysages par une dynamique d’enfrichement qui préoccupe les acteurs locaux. La caractérisation de cette dynamique, nécessaire pour comprendre et endiguer le phénomène, fait face à deux difficultés : (i) théorique, liée à la définition même du terme de friche, et (ii) technique, liée à la quantification et la qualification de l’enfrichement. Un protocole combinant photo-interprétation, inventaire de terrain et entretiens, a été appliqué pour caractériser la diversité des expressions paysagères de l’objet friche et envisager sa polymorphie. Ce travail se concentre sur trois secteurs du Beaujolais viticole afin de dégager les modalités sous-jacentes à l’enfrichement. Une typologie comprenant six types de parcelles en friche a été construite : chaque type présente un impact paysager différent au vu de sa physionomie. Trois filiations temporelles entre les types ont été identifiées : une famille de friches de coteaux, une de plaine dont les ceps ont été arrachés et une de plaine non-arrachés. L’enfrichement a en outre été quantifié et représente en 2017, respectivement, 1,5 %, 8,4 % et 8,7 % de la surface en vignes de la Basse-Ardières, du Marverand et du Merloux en 1999. Ces taux montrent un différentiel entre le nord et le sud du territoire, témoignant d’un vignoble plus résilient en Basse-Ardières (classification en cru) tandis qu’en Marverand et Merloux l’enfrichement est prépondérant.

<p>The landscape structure elements in agricultural catchments (ditches, hedges, pounds etc.) are known to have a major role in hydro-sedimentary transfers. They determine sediments availability, sediment pathways, water and sediments (de)coupling and connectivity patterns from source to sinks. However, linear drainage infrastructures remain often poorly represented in hydro-sedimentary modelling despite their major influence on flows redirection and concentration. Therefore, understanding the link between the catchment landscape structure and the transfer processes at its outlet is still a major challenge. Graph theory has been proved to be a significant tool to investigate sediment connectivity among agricultural catchments as it allows an explicit representation of linear and punctual elements of the landscape.</p><p>Based on a detailed inventory of linear landscape elements and a continuous monitoring of sediment fluxes, we built a new graph theory framework to comprehend sediments transfers in a dense agricultural drainage network in the Beaujolais vineyard (France). It integrates all types of linear infrastructures that might canalize water and sediment fluxes (tracks, ditches and soil bunds) and sediment traps used by winegrowers. From the intersection of the drainage network and a topographic graph, we went for spatial analysis and applied the index of connectivity (IC), to extract effects of (dis)connectivity and to compare several spatial configurations (i.e. topographic graph excluding linear infrastructures). To small catchments (8km²) of the Beaujolais vineyard are compared the effect of different landscape structures on sediment connectivity. Drainage network outlets were extracted to distinguish direct connections to the river in comparison to sediment sinks. The network structure emphasizes a reduction of sediment connectivity on the upper slope unlike on the lower slope where it is increased. Describing sediment structural connectivity through landscape structure analysis allows to identify the drainage infrastructures efficiency and might be of interest in a management perspective.</p>

Drainage infrastructure is an important element of the agricultural landscape, influencing hydro-sedimentary transfers from plots to rivers. The objective of this paper is to demonstrate how the description of the main characteristics of drainage networks allows a better understanding of sediment (dis)connectivity. This study focuses on an 8 km 2 catchment in the Beaujolais vineyards (France) that is characterised by a complex drainage network. We applied methods using field surveys, a geographical information system, and graph theory to map and analyse how such man-made infrastructures may act as barriers, buffers, or shortcuts. The catchment shows dense and complex drainage networks characterised by sediment trapping strategies in the upper slopes, and flow concentration and export in the lower slopes. The results exemplify winegrowers' strategies to disconnect sediments sources from the river to preserve soil resources.