Evapotranspiration, land cover, and climatic factors in southeastern Mexico and Central America

Abstract Evapotranspiration is a vital component of the hydrological cycle, returning approximately 65% of precipitated water to the atmosphere, influenced by soil characteristics and vegetation cover. Understanding its spatial and temporal distribution is essential for grasping climatic phenomena, cloud formation, and the impacts of various land uses. This study analyzed the spatiotemporal variation of evapotranspiration (ET) and its relationships with precipitation (P), temperature (T), and the Enhanced Vegetation Index (EVI) in southeastern Mexico and northern Central America over 20 years (2002–2021). Satellite data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor were used to analyze ET and EVI, complemented by gridded climate data for P and T. The study considered subregions characterized by distinct vegetation types, including tropical evergreen forests, tropical dry forests, pine-oak forests, and grasslands. The results indicate that the T trend is a significant driver of increasing ET in the region. Although the P variation did not show a significant trend, decreases in precipitation were negatively correlated with both EVI and ET. A subregional analysis revealed that tropical evergreen forests exhibited the highest ET values, peaking in February and July. Mixed oak-pine forests reached their maximum ET from May to September, while tropical dry forests showed clear seasonality, with peaks from June to September and minima from December to April. This seasonality is closely linked to the annual plant growth cycle and interannual and seasonal precipitation patterns. These results highlight the complex interactions between climatic factors and evapotranspiration across different vegetation types.