Estimation of the Spatiotemporal Distribution of Soil Carbon Fluxes in the Conceição do Coité Region (Bahia, Brazil) Using Remote Sensing Data

Resumo

As climate change worsens, it is essential to seek efficient climate monitoring strategies and develop low-cost, broad-coverage models to assess carbon dioxide (CO₂) fluxes in semiarid ecosystems. This study proposed to estimate the spatiotemporal dynamics of carbon flux (CO₂flux) in soils of the semiarid region, in the municipality of Conceição do Coité (Bahia, Brazil), between 2020 and 2024. Data from Sentinel-2 satellite images were used, processed in Google Earth Engine, integrating the NDVI and PRI indices. The data were evaluated in two climatic periods: rainy period (RP) and dry period (DP). Overall, the average soil carbon flux indices between each climatic period, across the years studied, were 0.172 for RP and 0.112 for DP. The results revealed that CO₂flux is directly related to the rainfall regime, with higher values in wetter years, such as 2021, and a significant drop in 2023 and 2024. The Caatinga vegetation responded positively to the rainfall, resulting in higher rates of carbon sequestration in areas with vegetation cover. Adapted to the conditions of the semi-arid climate, the cultivation of Agave sisalana, widespread in the studied region, has the potential to contribute to the reduction of greenhouse gas emissions and the recovery of degraded areas. The study also showed that remote sensing data can be considered a low-cost strategic tool for environmental monitoring associated with CO2 fluxes in soils and for the implementation of actions aligned with the Sustainable Development Goals (SDGs). In the context of the current climate crisis, reduced carbon flux in water deficit scenarios may contribute to a decrease in the carbon sink potential of soils, weakening their role as a climate regulator.