Delineating reservoir area using geologic remote sensing analysis, Jizan (Saudi Arabia): Implications for geothermal exploration

Jizan Province is considered one of the potential geothermal areas in Southwest Saudi Arabia. However, the prospective geothermal reservoir is still not delineated and the geothermal energy reserve is not estimated properly. Therefore, this study aims to delineate the geothermal prospect area using remote sensing-based analysis. Permeable areas, the high anomaly of Land Surface Temperature (LST), and the existence of granitic rock were the parameters used in the remote sensing analysis. Digital Elevation Models (DEM) SRTM and Landsat 8 images were used as the data source. Automatically- and manually-extracted structural lineaments supported by fractures/faults interpretation were integrated to generate a final map of the permeable areas defined in the study area (with three main permeable zones; Zones 1, 2 and 3). The average value of five LST maps and the Natural Different Building Index (NDBI) were used to investigate the high anomaly of LST. Final fuzzy logic integration of the defined permeable area, high LST anomaly, and the existence of granitic rock allowed a unique opportunity for the delineation of the prospective geothermal reservoir area. Remote sensing results were validated using the field-based studies performed in the same area. Three zones are suggested as prospective geothermal potential areas (Zones A, B, and C), where Zone A is the most favourable due to its estimated largest area and is interpreted to belong to the same geothermal system as Zone C. This study improves the understanding of the prospective geothermal reservoir area in Jizan based on the delineation of high permeable zones, and high anomaly LST. The spatial distribution of radiogenic elements in the rock units is also considered an indicator of the heat source of the geothermal system.