Spatial analyses with Geographic Information Systems: development of land suitability assessment methods for agricultural facilities and nature-based solutions

This study develops and tests GIS-MCDA methodologies for land suitability in Emilia-Romagna, Italy, focusing on an aquaponic systems and nature-based solutions (NbS). The first objective involves determining optimal locations of an innovative integrated multi-trophic aquaponic systems, while the second addresses NbS for the maximisation of carbon sequestration across urban, peri-urban and agricultural zones with three specific NbS. For the aquaponic system analysis, the region was divided into 50 × 50 m grid cells, each of them was assigned a suitability score from 0 to 8. Here, a score of 0 indicates unsuitability, 1 represents minimal suitability and 8 denotes maximum suitability. A significant portion of the assessed area was deemed unsuitable for aquaponic facilities. However, over 86.4% of the suitable areas received scores of 6, 7, or 8, highlighting the overall high potential of the Emilia-Romagna region for aquaponic development. The NbS analysis was tailored to maximise carbon sequestration. Each environmental zone was subdivided into 30 × 30 m cells, assigned suitability values from 1 (least suitable) to 5 (most suitable). Findings suggest that street tree NbS are most suitable for urban areas, green spaces area NbS for peri-urban areas and buffer strip NbS for agricultural areas. The results offer a strategic framework for sustainable spatial planning, allowing policymakers to identify optimal locations for implementing new NbS. The robustness of the models was validated using sensitivity analyses, confirming the reliability of the proposed methodologies.