Considering that karst caves, underground rivers, and dissolution fractures in shallow carbonate formation in the Sichuan Basin are extremely developed, leakage, failure and plugging difficulties are easy to occur in the drilling process. The TDEM was used to carry out the exploration of hidden karst geological bodies in well QM2, and the quasi-three-dimensional inversion based on lateral constrain was used to invert the TDEM data. Three NW trending anomalous bands were identified in the lower Triassic Jialingjiang Formation within the range of drilling, consisting of seven relatively low-resistivity anomalous zones. Under the guidance of TDEM quasi-three-dimensional inversion resistivity data, the low-resistivity karst development area is avoided, and the specific drilling location of well QM2 is determined. No karst cave and underground river were drilled in the later drilling process of well QM2, as well as no instability phenomenon occurred. It indicates that the TDEM detection results are consistent with the actual drilling, and the quasi-three-dimensional TDEM inversion interpretation data based on lateral constraints is reliable and can accurately detect the buried karst in the wellsite.

To address the challenges of high cost, complex deployment, and difficulties in real-time early warning for small landslides near residential areas, a portable and low-cost high-frequency monitoring device based on Micro-Electro-Mechanical Systems (MEMSs) was developed, and an advanced warning algorithm based on anomaly intensity factors was constructed. The device is easy to install and can collect and transmit data to the cloud in real time. Equipped with edge computing capabilities, it can independently analyze data in the absence of network connectivity and transmit real-time early warning information to terminals within a range of 5 km. To verify the performance of the system, a large-scale outdoor landslide simulation test site was constructed, where slope failure was induced through artificial rainfall to obtain the complete process data from deformation to failure. The experimental results demonstrate that the proposed early warning algorithm effectively identified different stability levels, providing warnings up to 13 s prior to catastrophic failure, confirming the high sensitivity and reliability of the device. This study offers a cost-effective and efficient approach to landslide monitoring and early warning, with notable prospects for broader implementation in practice.

The increase in thermal infrared brightness temperature and infrared emissivity observed during rock loading provides important insight into the physical mechanisms underlying thermal infrared anomalies associated with geological hazards, including earthquakes, landslides and rockbursts. However, the relationship between rock emissivity and brightness temperature is strongly influenced by the surrounding radiative environment, and how background radiation affects this relationship remains insufficiently understood. From the perspective of remote-sensing physics, this study investigates the influence of background radiation on the emissivity–brightness temperature relationship at the surfaces of multiple rock types. Experiments involving background-radiation measurements and rock-emissivity retrievals were conducted under different environmental conditions, and a physical relationship between background radiation and rock-surface brightness temperature was established. The results show that (1) the background radiation in the outdoor environment is mainly derived from the cold sky background, while the background radiation in the indoor environment tends to be close to the body radiation; and (2) in the indoor environment, the change in the emissivity is almost incapable of causing a brightness temperature response, and it is difficult to realize emissivity inversion, while in the outdoor environment, the mapping relationship between brightness temperature and emissivity is more relevant. Based on these findings, we developed an experimental configuration combining a movable chamber that opens to expose the loading platform to the sky with a multi-angle remote sensing observation loading platform designed to reduce structural obstruction. This configuration enables switching between enclosed and open-air conditions without relocating the loading platform and increases the contribution of cold sky background radiation to the radiation incident on the rock surface. The proposed experimental configuration may improve the reliability of laboratory thermal infrared rock-mechanics experiments and facilitate the investigation of stress-induced thermal infrared responses in rocks.