Land use/land cover (LULC) analysis is fundamental in sustainable development planning and landscape interpretation. The study explores the potential of the proposed harmonization of LULC geodata from SMOS (Portugal) and SIOSE (Spain), and updated with Sentinel-2. The spatial scope is the transboundary Lower Guadiana (SW Iberian Peninsula), where the aim is to assess the formation of new land uses and landscapes linked to renewable energies. It was found that the LEAC methodology (Land and Ecosystem Accounts, EEA), showed an adequate detection of flows and changes, with consistent and coherent results, typical of a homogeneous mapping system.