Assessing subnational vulnerability and multi-hazard risk to extreme hydrometeorological events in Central-Northeastern Argentina

Extreme hydrometeorological events (EHEs) represent a growing challenge for central-northeastern Argentina, where climatic variability interacts with structural socio-economic inequalities to shape spatially differentiated patterns of vulnerability and risk. This study develops a subnational‑scale assessment that integrates physical hazard indicators with socio-economic, demographic, and environmental variables to evaluate vulnerability and multi-hazard risk to EHEs at both long-term and short-term timescales.

Risk is evaluated at the subnational scale for 1991–2020 as the interaction between EHE hazards and regional vulnerability. Hazards are derived from ERA5 reanalysis data and examined both individually—distinguishing long-term hazards such as prolonged water excesses and deficits, and short-term hazards including heatwaves, intense precipitation, and flash droughts—and jointly through multi-hazard indices. Individual EHE hazards are evaluated based on their frequency, duration, and intensity. Vulnerability is conceptualized through exposure, sensitivity, and adaptive capacity, using census and geospatial information provided by national agencies. Exposure reflects the spatial overlap between population, crop yields, and critical infrastructure. Sensitivity captures demographic and socioeconomic fragility, as well as environmental susceptibility. Adaptive capacity encompasses healthcare, technological, and educational resources. Individual and multi-hazard risks are then computed by integrating standardized hazard indices with the vulnerability index.

The region exhibits an overall medium level of vulnerability, but with significant spatial contrasts. Central Argentina—including part of the country’s core crop region, where population and economic activity are concentrated—shows medium‑to‑low vulnerability, driven by high exposure yet moderated by low sensitivity and high adaptive capacity. In contrast, central‑northern Argentina—characterized by limited agro‑industrial and technological development—exhibits high vulnerability due to elevated sensitivity and restricted adaptive capacity, despite comparatively lower exposure levels. These patterns reflect broader regional socio‑environmental inequalities, where structural deficits intensify climate impacts. Regarding EHE hazard risks in the study region, heatwaves and long-term extreme precipitation deficits emerge as the highest-ranking risks both locally and regionally, coinciding with elevated hazard levels in the northern and northwestern areas, where vulnerability is likewise greatest. Although the eastern and northeastern areas exhibit the highest hazard levels for intense precipitation and long-term precipitation excesses, the associated risk is moderated by their medium vulnerability. Flash drought risk remains low and spatially restricted. Multi-hazard analysis reveals that the long-term combined risk is the highest and most widespread, whereas the short-term multi-hazard risk is more localized but strongly dominated by heatwaves.

This study provides an integrated framework for understanding subnational vulnerability and multi-hazard risk to EHEs in Argentina. The results show that the socio-environmental conditions act as amplifiers or attenuators of EHE hazards, shaping the resulting risk across the region. Moreover, the dominance of long-term multi-hazard risk indicates that prolonged climatic stresses can intensify the impacts of short-term extremes. These findings underscore the need for differentiated adaptation strategies: reducing exposure in the south through improved land‑use planning, infrastructure development, and climate‑resilient agricultural management, and strengthening adaptive capacity in the north through investments in health, education, and institutional systems. Despite limitations related to data availability and indicator selection, the results offer actionable insights for territorial planning and climate adaptation.