Abstract Aquifer structure plays a critical role in controlling groundwater flow through both saturated and unsaturated zones. In remote and rugged terrains, GIS and remote sensing tools are essential for delineating geological structures. This study integrates stereoscopic aerial photograph analysis and GIS-based hill-shading techniques to enhance lineament detection within the Ziria karst system in northern Peloponnese, Greece. By combining these techniques, 1,214 lineaments were identified, revealing structural and erosional features that were not detected using a single approach. Field validation confirmed that lineaments identified by aerial photography corresponded to faults or fracture systems, with a predominant NNW–SSE orientation. Fracture network analysis was subsequently applied to assess structural feature connectivity. The results indicated a low degree of connectivity within the lineament dataset, with isolated (I) features being more prevalent than branching (Y) and intersection (X) nodes. Additionally, detailed karst landform mapping identified 325 karst depressions, where approximately 62.5% of the depressions were in direct association with the identified lineaments. The majority of the remaining karst depressions, while not in direct contact, were predominantly located within zones characterized by high lineament density. The mapped lineaments were ultimately used to refine the boundaries of the karst aquifer, defined by crystalline metamorphic bedrock, and to update the area’s groundwater vulnerability and recharge regimes. The findings emphasize the role of structural control in shaping hydrological systems, offering a robust framework for assessing various hydrogeological aspects and guiding effective groundwater management in tectonically active karst regions.
Nanou et al. (2026) studied this question.