Satellite-Based Delineation of the Urban–Rural Interface Using Landscape Heterogeneity Metrics: Evidence from Three Argentine Cities

Urban–rural interfaces are transitional territories characterized by the coexistence of urban, agricultural, and natural land covers. Despite their relevance for territorial planning and environmental management, their spatial delineation remains methodologically challenging due to their dynamic and heterogeneous nature. This study proposes a reproducible remote sensing-based approach for delineating urban–rural interfaces and evaluating their spatial coherence through landscape heterogeneity metrics. The method was applied to three intermediate Argentine cities representing contrasting environmental contexts: Córdoba, Rosario, and Mendoza. Interface areas were identified by combining nighttime light intensity, the Normalized Built-up Area Index (NBAI), and the Normalized Difference Vegetation Index (NDVI) within Google Earth Engine. To evaluate the coherence of the resulting delineations, five alternative interface configurations were generated using different nighttime light thresholds and assessed through landscape metrics describing diversity, interspersion, fragmentation, and spatial structure. The workflow produced spatially coherent candidate interface areas in all three cities, producing spatial patterns consistent with local urban expansion processes. The highest heterogeneity values occurred at different interface extents among cities, with intermediate configurations generally showing the strongest responses. Among the evaluated metrics, Shannon Diversity Index (SHDI) and Interspersion and Juxtaposition Index (IJI) provided the most consistent results. The findings suggest that spatial heterogeneity constitutes a useful criterion for assessing the coherence of interface delineations, while highlighting that maximum heterogeneity does not necessarily correspond to the most operationally suitable boundary for territorial management.