Blog
Geophysical Techniques for Landslide Detection and Monitoring
Geophysical Techniques for Landslide Detection and Monitoring
Dr. Sanjay Rana
Introduction
Landslides are one of the most common natural disasters, affecting several regions worldwide. Landslides result in loss of life, property damage, and destruction of infrastructure. Early detection and monitoring are crucial to mitigate the impact of landslides. Geophysical techniques have been widely used in the identification and assessment of landslide hazards. This paper provides a technical overview of the use of geophysical techniques for landslide detection and monitoring.
Geophysical Techniques:
Geophysical techniques involve the study of the physical properties of the earth to identify subsurface anomalies or changes in the natural environment. These techniques are non-invasive and can provide information on subsurface features without the need for drilling, excavation, or other invasive methods. The following are some of the commonly used geophysical techniques in landslide detection and monitoring:
1. Ground Penetrating Radar (GPR):
GPR is a non-destructive geophysical technique that uses radar pulses to image the subsurface. It can be used to identify the internal structures and composition of the subsurface. In landslide monitoring, GPR can be used to detect changes in slope morphology, soil stratification, and the presence of subsurface voids or cavities.
2. Electrical Resistivity Tomography (ERT):
ERT is a geophysical technique that measures the electrical resistivity of subsurface materials. It can be used to detect changes in moisture content, density, and porosity of subsurface materials. In landslide monitoring, ERT can be used to identify the zone of weakness or failure plane, which can serve as early warning signs for landslide events.
3. Seismic Refraction:
Seismic Refraction is a geophysical technique that measures the velocity of seismic waves through the subsurface. It can be used to identify changes in subsurface structures, such as fracture zones, faults, or cavities. In landslide monitoring, seismic refraction can be used to detect changes in the subsurface layers and the presence of potential sliding zones.
4. MASW:
The use of Multichannel Analysis of Surface Waves (MASW) for landslides has gained significant interest in recent years due to its ability to accurately measure the subsurface structure and potential instability of slopes. MASW is a non-invasive geophysical method that uses seismic waves to determine the shear wave velocity profile of the subsurface. By analysing the resulting data, experts can identify layers of soil or rock that may be prone to slipping or sliding, allowing for early detection and preventive measures. Studies have shown that MASW is a reliable and efficient technique for landslide investigations in various geological settings. Its non-destructive nature and ability to provide detailed subsurface information make it a valuable tool for landslide risk assessment and management.
4. LiDAR:
Light Detection and Ranging (LiDAR) is a remote sensing technology that uses laser pulses to measure the distance between the sensor and the target. In landslide monitoring, LiDAR can be used to generate high-resolution topographic maps and identify changes in slope morphology that can indicate potential landslide events.
Conclusion:
Geophysical techniques have proven to be effective in detecting and monitoring landslide hazards. By providing non-invasive and real-time information on subsurface changes, geophysical techniques can help reduce the impact of landslides on the environment and public safety. The accurate identification of potential landslide zones and early warning systems can facilitate better land-use planning and improve disaster preparedness.
.jpg)
