Integrated Geophysical Characterization of Hot Dry Rock Resources in the Gonghe Basin, Qinghai, China

Hot dry rock (HDR) represents a promising form of clean and renewable geothermal energy, with substantial global potential to support the transition to low-carbon energy systems. Among the most prospective regions for HDR development in China is the Gonghe Basin in Qinghai Province. However, the basin's complex subsurface geological conditions present significant challenges for the accurate assessment of HDR resources.This study proposes a multi-scale integrated geophysical framework for HDR characterization, combining gravity, magnetic, magnetotelluric (MT), ambient noise tomography, and time-frequency electromagnetic methods. Multi-source geophysical datasets were systematically processed, calibrated with available borehole data, and interpreted through inversion modeling to construct a three-dimensional geological-geophysical model of the study area.The results reveal the spatial distribution, burial depth, and thermal-structural properties of HDR reservoirs, identifying a high-potential zone with reservoir temperatures exceeding 200 °C. The integrated approach effectively addresses the limitations of individual geophysical methods, significantly enhancing the accuracy of HDR reservoir identification and parameter estimation. This study demonstrates the feasibility and effectiveness of integrated geophysical techniques in HDR exploration, offering a robust technical basis for future development in the Gonghe Basin and similar geothermal environments worldwide.