<p>Subsidence is a well-documented issue in the El Bajío region of central Mexico, particularly in Querétaro City, where regional ground sinking has been observed since the 1970s, primarily due to groundwater overexploitation. However, over the past decade, localized surface deformations and earth fissures have emerged in the city’s northwestern sector, an area that, before 2000, was used for agriculture and shrublands and hosted banks of volcanic materials. Since then, the area has experienced rapid urbanization, including residential, industrial, and commercial development, as well as the construction of new roads. Beginning in 2014, residents began reporting ground deformations, cracks in buildings and infrastructure, sinkholes, and water leaks. To investigate these phenomena, we conducted geological assessments through field campaigns, UAV-based photogrammetry, and Ground Penetrating Radar (GPR) surveys between 2022 and 2024 across five study sites. This paper presents findings from two of those sites, where the subsurface is composed of unconsolidated volcaniclastic deposits. UAV photogrammetric data revealed vertical displacements ranging from 0.15 to 1.2&#xa0;m, while GPR results confirmed that the deformations are shallow, localized, and driven by ongoing erosion and compaction of loose materials, further aggravated by heavy traffic loads and water infiltration. Notably, the affected areas coincide with former volcanic material banks that were subsequently filled and developed for road infrastructure. Our findings indicate that the observed ground deformations are primarily the result of anthropogenic activities, rather than regional subsidence processes.</p> Graphical Abstract <p>The graphical abstract summarizes an assessment conducted to identify the origin of newly formed superficial deformation zones in a study area in Mexico. This investigation integrates UAV-based and Ground Penetrating Radar (GPR) surveys with geological data and is presented through four key components. First, the geographical context includes regional and local scales. A location map illustrates Querétaro Citys urban expansion since 2003 (shaded in grey), outlines the study area (red rectangle), and shows changes in Land Use and Land Cover (LULC) along with geological and anthropogenic factors linked to surface deformation. Second, one of the observed problems is depicted with an image showing a sinkhole in a main road. Third, the methodology combines: (a) geological fieldwork to map and interpret exposed geological units; (b) seasonal UAV photogrammetric surveys conducted over three years (2022–2024) at five sites to generate Digital Surface Models and orthomosaics for monitoring deformation; and (c) multi-frequency GPR surveys at three locations to detect subsurface discontinuities that may contribute to instability. Fourth, the findings focus on two of the five monitored sites, where similar deformation patterns were observed. These are linked to the inadequate compaction of fill material used to reclaim abandoned open-pit quarries composed of volcaniclastic deposits. Roads built over these reclaimed sites are now showing signs of surface rupture and displacement, confirmed by satellite imagery. The study concludes that the observed ground deformation at these sites is not due to natural subsidence but rather to human-induced ground instability. This suggests a high risk of continued surface rupture, emphasizing the importance of considering anthropogenic factors in urban development planning.</p> <p></p>