Climate Crisis Fuels Landslide Surge on Pakistan's 'Tourism Highway'

A critical joint study by Pakistani and Chinese researchers has linked climate change to a significant rise in non-seismic landslides along Pakistan's scenic yet crucial N-15 highway, which covers Balakot, Babusar Top, Naran and Chilas, often dubbed the 'tourism highway'.

The research team analyzed climate data and 455 satellite images of the route. It recorded 335 non-earthquake-related landslides that occurred between 1990 and 2023, with debris repeatedly blocking the infrastructure.

Scientists followed a three-step research framework to reach their conclusion. First, they collected Landsat and Sentinel-2 satellite imagery to remotely assess the area.

In the second step, they downloaded Google Earth images to verify the landslide locations and delineate their boundaries.

Finally, the team conducted on-site surveys in areas where the satellite data had indicated potential landslides.

The core finding indicates that the erratic patterns of heat, snowmelt and rising precipitation are destabilizing the mountain slopes. Data confirmed that the frequency of landslides began to rise gradually, with a major surge noted after 2005, corresponding with a documented increase in temperature and rapid snowmelt in the region. 

The study found that over 84% of incidents occurred in the warm season (April–October) and over 86% took place on steep slopes (steeper than 40 degree).  

Landslide dynamics are different due to the diverse geological makeup of the areas. For instance, Balakot holds sub-tropical conditions where high precipitation (water in the form of ice and rain) is the main cause of landslides.

Area from Babusa Top to Naran is alpine (above the tree-line) where soil moisture and precipitation trigger landslides, while Chilas is a semi-arid region where geological features and heat are the main causes of landslides.

So, the study provides a good understanding of three different climatic-mountain regions for future risk assessment, infrastructure planning, early warning systems and disaster prevention.

Climate Connection to Calamities

Climate change is accelerating landslide risk, particularly since 2005. Rising temperatures increase the rate of snow and ice melt, which thaws frozen ground, thus raising underground water pressure. Simultaneously, erratic changes in rainfall worsen surface runoff and soil saturation. Both processes significantly increase the likelihood of landslides.

Identifying High-Risk Areas (Slippery Slopes)

While local factors like geology, soil type, and moisture play a role, the steepest mountains are the most vulnerable to mudslides. Researchers utilized satellite elevation data (12.5m ALOS PALSAR) and high-resolution Google Earth images (3.4m), validated by field visits, to map risk. This analysis revealed --  Over 86% of incidents occurred on slopes exceeding a 40 degree incline and 65% took place at elevations between 1,000 and 2,500 meters. These specific details are critical for effective disaster planning and early warning systems.

On-Ground Validation and Local Integration 

Field visits along the N-15 Highway (August 2022 and April 2023) confirmed satellite-based instability findings, such as damaged infrastructure and displaced debris in areas like Balakot. 

Nazir Ahmed Bazai (China Pakistan Joint Research Center) highlighted the need to integrate local knowledge:"Through interviews with locals, we learned how they’ve adapted... by avoiding high-risk areas during the monsoon. However, these community responses are often reactive, not proactive, due to limited resources. Integrating local knowledge with scientific data is crucial for effective early warning systems and building long-term community resilience."

Strategies for Long-Term Resilience

Bazai proposed a combination of 'natural and non-natural' solutions to manage the problem:

Bioengineering: Employing low-cost methods like planting deep-rooted vegetation to stabilize high-risk areas (Balakot and Naran).

Infrastructure: Installing protective barriers and improving drainage systems along the highway to lessen landslide frequency and severity.

Monitoring: Using low-cost sensors for real-time tracking of rainfall, soil moisture and snowmelt, especially near Babusar Pass, to provide timely warnings for both locals and tourists.Education: Enhancing community preparedness through programs focused on evacuation procedures and monitoring tools.

The Fatal Reality and Expert Recommendations

Previous data shows the severity of the threat, with the Global Fatal Landslide Database recording 1,583 deaths from 215 non-seismic landslides in Pakistan between 2004 and 2016.

Dr Melanie Froude emphasizes a crucial three-part framework—'research, regulate, and educate'—to manage these localized geo-hazards:

Research: Understanding how hillslope materials respond to environmental changes is essential for identifying slope instability.

Regulation: Strict enforcement of national guidelines regarding construction methods, building size and foundations in mountainous regions.

Education: Providing accessible, straightforward guidance on low-cost, safe slope engineering (such as maintaining vegetation and proper drainage) to communities that cannot afford technical engineering expertise.

Source: The Express Tribune