Influence of land use and cover on the spatio-temporal analysis of the energy balance in a conservation unit

Abstract

This study employs Landsat satellite imagery, interpolated meteorological data and the Surface Energy Balance Algorithm for Land (SEBAL) to estimate the energy balance and evapotranspiration (ET) within the Itupararanga Environmental Protection Area (Itupararanga EPA), located in the Atlantic Forest biome of Brazil. The results indicate that urban areas show the lowest average daily evapotranspiration (ET24) values, whereas water bodies and vegetated areas have the highest ET24 values. Urban areas also recorded the highest surface albedo (α) values across all years analysed. While there was a general trend of increasing net radiation values over time — leading to higher evapotranspiration rates, with peak values observed in 2021 — this trend does not suggest a direct correlation between net radiation and ET. This underscores the critical role of land cover in modulating water fluxes. Zonal statistical analysis revealed that agricultural areas contributed more to ET than pastures, whereas forests and forestry areas exhibited similar impacts on ET. Land-use changes were found to significantly influence ET; urban areas, in particular, retained more heat and had reduced energy availability for evapotranspiration. This research enhances the understanding of the energy balance within the Itupararanga EPA and provides valuable data to support water resource management and environmental conservation efforts.