India is expanding the use of satellite monitoring, geological mapping and engineering interventions as part of a broader effort to address landslide risks on National Highways in mountainous regions.

The Ministry of Road Transport and Highways (MoRTH) announced a series of initiatives focused on highway corridors in the Himalayas and other geologically sensitive areas. The measures follow recent extreme weather events, including cloudbursts and flash floods in Uttarakhand, which caused damage to infrastructure and disrupted transport links.

According to ministry data, India's National Highway network exceeds 146,570 kilometers, of which about 16,788 kilometers are located in hill states. Many of these routes pass through terrain vulnerable to landslides, rockfalls, flash floods and slope instability.

Satellite Monitoring And Early Warning Systems

Among the projects under implementation is the use of Interferometric Synthetic Aperture Radar (InSAR) technology along a 100-kilometer section of the Char Dham route in Uttarakhand. The system is designed to detect small ground movements that may indicate changes in slope conditions.

MoRTH has also outlined plans for a monitoring and alert system on the Parwanoo-Solan section of National Highway-5 in Himachal Pradesh. According to the ministry, the system will track factors such as landslides, land subsidence, groundwater movement and rockfall-prone areas.

The ministry has signed agreements with organizations involved in satellite-based monitoring and geospatial analysis as part of these efforts.

MoRTH said geological data from the Geological Survey of India (GSI) is being incorporated into highway planning, tunnel investigations and route alignment studies. The ministry and GSI have also signed an agreement covering geological investigations and data sharing related to geohazards.

The ministry has introduced a phased approach for highway construction in hilly terrain. Under the policy, slope cutting and stabilization measures are completed before road construction progresses further. Officials said slope conditions are monitored through at least one monsoon season before subsequent stages begin.

Additional land acquisition provisions have also been introduced in some projects to accommodate slope stabilization and maintenance requirements.

Scientific Assessments And Mitigation Measures

According to MoRTH, site investigations are increasingly using drones, LiDAR surveys and digital terrain models to assess terrain conditions. The ministry said mitigation measures are selected based on factors including geology, groundwater conditions and rainfall patterns.

Techniques being used in various projects include soil nailing, retaining structures, drainage systems, rock anchors and steel mesh installations. Nature-based measures, including vegetation-based slope stabilization, are also being examined in some locations.

The ministry has also announced partnerships with institutions including THDC India Limited, the Geological Survey of India, the Defence Geo-informatics Research Establishment, the National Institute of Rock Mechanics and IIT Roorkee for technical studies, design reviews and geohazard assessments.

In Uttarakhand, MoRTH said mitigation work has been completed at 58 landslide-prone locations, while work is underway at 96 sites. Investigations and project reports are being prepared for another 104 locations.

Experts have noted that monitoring systems and engineering measures can support risk management in mountainous regions, although their effectiveness depends on local geological conditions, maintenance practices and the timely implementation of mitigation measures.