Integrated SBAS-InSAR, Land-Cover Transformation, and Seismic Analysis for Assessing Urban Surface Deformation in the Abuja Basement Complex, Nigeria

Surface deformation in rapidly urbanizing basement complex environments reflects the combined influence of geological conditions, anthropogenic transformation, environmental variability, and episodic seismic processes. This study develops an integrated framework combining Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR), multi-temporal land use/land cover (LULC) analysis, and seismic ground-motion assessment to investigate urban surface deformation across the Abuja Municipal Area Council (AMAC) and adjoining parts of Bwari Area Council, Nigeria. A total of 175 Sentinel-1 ascending Interferometric Wide (IW) acquisitions from 2017–2024 were processed using SBAS-InSAR to derive line-of-sight (LOS) deformation patterns. Landsat-derived LULC datasets for 2004, 2014, and 2024 were classified using Maximum Likelihood Classification, while seismic observations associated with the 2018 (ML 3.0) and 2024 (ML 3.2) events were evaluated using ground-motion prediction equation (GMPE)-assisted peak ground acceleration (PGA) and peak ground velocity (PGV) indicators. Results reveal a heterogeneous deformation field dominated by negative LOS displacement responses, with a mean LOS deformation velocity of −2.284 mm/yr and persistent deformation hotspots around Mpape, Katampe, Maitama, and Kubwa. Temporal analysis indicates increased deformation variability during seismic observation periods; however, rainfall-controlled assessment suggests that these responses reflect combined geological, hydrological, anthropogenic, and seismic influences rather than exclusively earthquake-induced displacement. Spatial analysis identified moderate associations between LOS deformation and seismic ground-motion indicators, with correlations of ρ = 0.56 for PGA and ρ = 0.63 for PGV. LULC analysis reveals substantial urban expansion, with built-up areas increasing from 8.4% in 2004 to 34.7% in 2024, while vegetation declined from 39.0% to 17.3%. Statistical analysis indicates significant effects of LULC category, geological substrate, and their interaction on deformation variability (p < 0.001). The findings demonstrate that deformation within the Abuja Basement Complex reflects a multifactor system influenced by geological structures, urban transformation, environmental variability, and episodic seismic processes, providing an improved framework for urban geohazard assessment.