GIS-based multi-criteria territorial suitability assessment for insect farms: a case study for North Italy

Although environmental sustainability and economic feasibility frameworks have been developed to evaluate the impact of insect farms, significant studies on the development of territorial suitability methods specifically tailored to insect production have not yet been performed. This work proposes a GIS-based multi criteria decision making analysis to evaluate the suitability of a territory to the installation of insect farms. A case study developed specifically for black soldier fly Hermetia illucens (HI) insect farms in Emilia-Romagna region (North Italy) is presented. This is an area which, due to its agro-industrial nature and the consequent large production of related waste and by-products, is an optimal candidate for the installation of insect farms. Nine physical, environmental, and economic criteria were assessed. A raster spatial layer for each criterion was obtained, and their values were standardised. The criteria were weighted using the analytical hierarchical process, based on expert opinion recorded via an online questionnaire. The resulting weights were used to combine the single criterion maps using a weighted linear combination procedure and generate, after reclassification, the final suitability map. This map indicates the areas suitable for insect farms at the local level and provides indications for estimating suitability at regional and provincial level. The results showed that 56.2% of the study area was deemed unsuitable, and 43.8% was determined suitable for an HI insect farm; best locations were found around the main agro-industrial centres of the Po valley. The proposed methodology can be easily adapted to other breeding models, insects or study areas and adds valuable information in the development of guidelines for industrial-scale insect farms.