Geospatial Assessment of Urban Expansion Dynamics Integrating GHSL Data, Remote Sensing, GIS, and Spatial Metrics: Evidence from Zliten Municipality, Libya (2000–2025)

Abstract

Urban expansion is a multidimensional process involving changes in spatial organization, directional growth, dispersion, and morphological structure; however, these dimensions are often assessed independently, limiting an integrated understanding of urban transformation. This study develops an integrated geospatial framework to characterize urban expansion dynamics in Zliten Municipality, Libya, during 2000–2025. Multi-temporal built-up surfaces were derived from the Global Human Settlement Layer (GHSL) using Google Earth Engine and analyzed through complementary measures of growth, centroid displacement, directional expansion, spatial dispersion, and morphological complexity. Results indicate a total urban expansion of 26.40 km², with a compound annual growth rate of approximately 2.94%. Despite substantial growth, the urban centroid shifted by only 0.889 km, indicating limited displacement of the overall urban mass. The eastern sector dominated directional expansion (21.56%), while the resultant net growth vector was oriented SSE (158.5°). Shannon entropy increased from 0.685 to 0.737, indicating greater spatial dispersion, whereas a fractal dimension of 1.5436 reflects increasing morphological complexity. These findings demonstrate that Zliten’s urban transformation extends beyond areal growth to encompass spatial redistribution, directional reorganization, dispersion, and morphological restructuring. The framework provides a transferable basis for diagnosing complex urban growth dynamics and supporting evidence-based spatial planning in medium-sized, data-limited coastal cities.