GIS multi-threat models for agricultural land in the Nouvelle-Aquitaine region (France). A methodology of composite indicators to support targeted policies

Abstract

Food sovereignty is yet again a global and local priority. Nevertheless, the useful agricultural area continues to decrease. Land take is leading to increasing pressure on farmland, which is threatened by different phenomena - such as natural risks and demographic dynamics-. Farmland is therefore threatened by a number of different factors. A multi-criteria approach is needed to consider many factors and their interactions. Nevertheless, scientific understanding of the multi-threat approach is still limited when it comes to understanding the issue of agricultural land pressure. Thus, this research implements a multi-criteria evaluation workflow to develop multicriteria models of land threat on agricultural land based on four composite indicators: land take, energy competitiveness, natural and anthropogenic hazards, and demographic decline. These indicators are synthetized in a global multi-criteria model of agricultural land pressure. The study area is the Nouvelle-Aquitaine Region, the largest French region with 9 functional urban areas and 1,597,720 agricultural plots (39,458.2 sq.km). This research is entirely based on open data according to the INSPIRE Directive, using Geographic Information Systems (ArcGIS Pro). Results show high threat level in 242,525 plots (14.93 % of agricultural area) and very high levels in 380,202 plots (20.75 % of agricultural area). Land take and natural hazards definitively contribute to the threat level. The study reveals that plots under threat tend to be smaller than less threatened ones. Results can help local authorities develop targeted strategies to maintain the region's agricultural land and productive capacity. This contribution is scalable and replicable to other regions and countries.