Composite index assessment of climate vulnerability and resilience in subsistence agriculture at the local level

Abstract

Subsistence agriculture is highly vulnerable to climate change, and its resilience is constrained by local conditions and networks, negatively impacting livelihoods, food security, and local culture. In the Biobío region of Chile, subsistence farming is crucial for food security; however, it is expected to be significantly affected by climate change and requires a territorial instrument that systematizes agricultural, environmental, and social information for management and decision-making. This study evaluates the vulnerability and resilience of subsistence agriculture at the municipal level using composite indices. The vulnerability index was developed following the Intergovernmental Panel on Climate Change framework, integrating indicators of exposure, sensitivity, and adaptive capacity. The resilience index considered territorial multifunctionality, institutional interaction, and local territorial management and response capacity. Data were sourced from official records and scientific literature on climate, agricultural production, and territorial characteristics. Nineteen indicators were standardized on a scale ranging from 0 to 1, where higher values represented greater vulnerability or resilience, depending on the index considered. The indices were applied to evaluate 33 municipalities in the Biobío region, and the results were spatially represented. The Biobío region exhibited medium levels of vulnerability (0.594) and resilience (0.418). Coastal municipalities showed the highest vulnerability due to their reliance on rainfed agriculture, low crop diversification, and severe soil erosion. In contrast, mountain municipalities, such as Alto Biobío, exhibited higher resilience, reflecting comparatively greater territorial resilience capacities associated with diversified production systems, irrigation infrastructure, crop rotation practices, and stronger institutional linkages. The resulting indices offer a replicable and integrative methodological framework. Our findings highlight the need for targeted public policies on soil restoration, irrigation modernization, crop diversification, and strengthening local networks to enhance resilience. This approach provides a strategic tool for climate risk planning in rural agricultural territories.