Abstract: [Purposes]Aiming at the problems associated with concealed illegal open-pit mining activities,such as strong concealment,difficulties in evidence collection,and high accuracy requirements for mineral resource quantification, this study proposes an integrated identification method combining multiple technologies.These include UAV LiDAR surveying,USV-based underwater topographic mapping,ground-penetrating radar (GPR)detection,GNSS measurement,and geological investigation.[Methods] Taking a suspected illegal mining case in XY county,Jiangsu province as an example,high-precision digital elevation models were acquired using UAV LiDAR,underwater terrain data of water-filled pits were obtained with a USV-mounted single-beam bathymetric system,and the thickness and bottom boundaries of backfilled areas were detected via GPR.Comprehensive analysis was conducted incorporating historical remote sensing images,enabling precise delineation of the extent and depth of illegal excavation.The volume of the suspected illegally mined ore body was estimated using the geological block method,combined with rock physico-mechanical property tests,leading to an accurate determination of the quantity of illegally extracted mineral resources.[Findings]The research demonstrates that this method achieves precise verification of mineral resource volumes across the entire space of illegal open-pit mining areas,integrating land and water surfaces as well as above-ground and subsurface dimensions.[Conclusions]The results are objective,scientific,and reliable.The proposed method can provide robust technical support for law enforcement supervision and judicial identification.

Key words: illegal mining, mineral resources assessment, multi-technique integration, UAV LiDAR, underwater bathymetric survey, ground penetrating radar