Spatio-temporal evolution of surface water resources in the Brazilian semi-arid: a case study in the Sertão of Pernambuco

ABSTRACT The research analyzed the evolution of surface water in Serra Talhada, Brazil, over 31 years using remote sensing data from Google Earth Engine (GEE). It compared the NDWI and MNDWI indices with MapBiomas data to assess water dynamics in semi-arid regions. Accuracy analysis and the kappa index showed good agreement between datasets, while trend testing revealed significant temporal changes during dry and wet seasons. Despite irregular rainfall patterns, the MNDWI index proved more effective in quantifying surface water, highlighting greater water accumulation during the rainy season. Reservoir construction influenced water distribution, but annual water retention varied throughout the study. The results underscore the importance of strategic planning for reservoirs, particularly considering solar exposure, to ensure long-term water availability. The study emphasizes that sustainable water management is essential for environmental and socioeconomic resilience in semi-arid regions, especially in climate variability and increasing demand for water resources.