GIS-Based Geothermal Favorability Mapping and Geological Consistency Assessment in the Lower Kura Basin

Abstract

The Lower Kura Basin is a tectonically active sedimentary region of Azerbaijan where geological and hydrogeological conditions may favor geothermal fluid circulation. This study develops a Geographic Information Systems (GIS)-based multi-criteria framework for regional geothermal favorability mapping by integrating five spatial criteria: land surface temperature (LST), fault density, slope, drainage density, and elevation. LST was derived from cloud-masked Landsat 9 Collection 2 Level-2 surface-temperature products acquired during summer 2025, while the topographic and hydrological criteria were prepared using a 30 m digital elevation model. All thematic layers were standardized to a common 30 m grid and reclassified into five favorability classes using explicitly defined classification rules. Criterion weights were determined using the Analytic Hierarchy Process (AHP), and the resulting pairwise comparison matrix yielded a consistency ratio of 0.024, indicating acceptable internal consistency. LST and fault density received the highest weights because they represent surface thermal expression and potential structural controls on subsurface fluid circulation, respectively, whereas slope, drainage density, and elevation were treated as secondary or indirect criteria. The baseline model identified 3681.9 km2, corresponding to 27.71% of the study area, as having high or very high geothermal favorability. Two alternative weighting scenarios were subsequently evaluated to assess the sensitivity of the model to criterion weights. Despite substantial changes in the weighting scheme, 3624.0 km2 (27.27% of the study area) consistently remained within the high or very high classes across all three scenarios and were therefore interpreted as robust geothermal favorability zones. Geological consistency was assessed through spatial comparison with regional geological evidence and mapped mud-volcano occurrences, while faults were not treated as an independent validation dataset because fault density was included as a model criterion. The proposed framework supports the identification of priority areas for further geothermal investigation and may contribute to the broader development of clean and renewable energy resources in Azerbaijan. The identified zones represent priority areas for further geological, hydrogeological, geophysical, geothermal-gradient, and exploratory investigations rather than confirmed geothermal resources.