Tendências climáticas na bacia hidrográfica do rio Parnaíba (1994 a 2024): análise por sub-bacias

Abstract

This study analyzes climate trends in the Parnaíba River Basin between 1994 and 2024, aiming to evaluate precipitation, temperature, evapotranspiration, and soil moisture across its sub-basins. CHIRPS data were used for precipitation, and the FLDAS Noah model (FLDAS_NOAH01_C_GL_M) was used for temperature, evapotranspiration, and soil moisture; sub-basin boundaries were obtained from ANA. Annual series were extracted on Google Earth Engine and analyzed in Python; trends were tested using the Mann–Kendall test and Sen’s slope estimator, and the series were standardized using z-scores. The results show no significant trend in precipitation, a statistically significant increase in temperature (+0.025 °C/year), and a significant decrease in soil moisture (slope ≈ −8.9 units/year). Evapotranspiration showed spatial variation, with increases occurring mainly in the western portion of the basin. The study concludes that, despite stable rainfall, the warming and increased atmospheric water loss have reduced water availability, requiring urgent monitoring and adaptation measures tailored to each sub-basin.