Multicriteria environmental vulnerability modeling in hydropower basins of the southern Amazon using the AHP–Delphi approach

Hydropower development in the Amazon intensifies land use changes and environmental pressures, especially where multiple dams operate and exert cumulative influence. Understanding how these dynamics affect environmental vulnerability is essential for territorial planning. This study assesses environmental vulnerability in the areas of influence of the São Manoel and Teles Pires hydroelectric plants, located in the southern Amazon, integrating land use dynamics, climate variability, topographic conditions, vegetation, and anthropogenic factors. A multi-criteria decision analysis (MCDA) using the Analytic Hierarchy Process (AHP) and the Delphi method was combined with geoprocessing and land use change modeling (CA-ANN) to analyze vulnerability in 2013 and 2023 and project conditions for 2050. The CA-ANN model demonstrated high predictive performance (Kappa = 0.8432; overall accuracy = 90.23%), enabling simulations for future land use. Forest loss and the expansion of agricultural and pasture areas between 2013 and 2023 resulted in an increase in vulnerability classes from moderate to very high, particularly in areas with highly dissected and rugged terrain, shallow soils, and recurring fire activity. The projection for 2050 indicates a spatial redistribution of vulnerability, with a tendency toward intensification in areas associated with high rainfall, intense relief dissection, and low vegetation cover. These findings highlight the interdependence between land conversion processes, precipitation patterns, and geomorphological stability, reinforcing the need for strategic conservation actions, such as the implementation of Environmental Protection Areas (APAs) to mitigate cumulative impacts and maintain the ecological and operational resilience of the hydroelectric system.