Policymakers and local government officials must prioritize road safety by requiring thorough geological assessments for all major infrastructure projects, particularly in landslide-prone areas
This week, heavy rain has been falling continuously in various parts of Nepal. The capital city, Kathmandu, has experienced flooding, leading to casualties and damage to property. Many hilly highways have also been blocked due to landslides triggered by the persistent rain, leaving passengers stranded. According to officials, 65 highways have been obstructed, and the risk of landslides has increased in 42 districts. Tragically, more than 100 people have died as a result of floods and landslides across the country.
Every year, landslides occur on hilly highways, causing loss of life and damage to property. Nepal's highways, especially those in hilly regions, are becoming more vulnerable to landslides. For example, on September 28, a landslide at Jhyaple Khola along the Tribhuvan Highway in Dhading resulted in the deaths of 14 people when two buses were buried under debris. Similarly, on July 12, 2024, a landslide on the Narayanghat-Mugling road swept away two buses in the Simaltal area that left over 60 passengers missing.
These incidents are part of a larger problem, as Nepal experiences numerous landslides during the monsoon season. Data shows that more than 108 fatalities were reported due to landslides nationwide from June 10, 2024 to July 14. The Department of Roads has identified 25 areas along the Narayanghat-Mugling route that are particularly prone to landslides, with four of these classified as high-risk zones. These alarming incidents raise the question of whether these highways are ambushes.
Temporary fixes not enough: When it comes to disaster management, our governmental authorities have always taken a wait-and-see approach. For years, Nepal has mostly responded to landslides along highways by using temporary solutions. Clearing debris and reinforcing parts of the road after each landslide may help for a short time, but they don't fix the root problems. The frequent roadblocks and accidents during the monsoon season show that these quick fixes aren't enough. To create safer, long-lasting roads, we need to take a proactive, science-based approach to stabilising slopes and designing roads that can resist landslides.
Geotechnical assessments and hazard mapping: Before building any major road, a detailed geological and geotechnical survey should be carried out. These surveys check the stability of the slopes, the type of rocks and the soil along the planned route. Along with hazard mapping, which shows areas most at risk of landslides, these surveys help engineers design roads that either avoid the most dangerous spots or use special methods to reduce the risk.
In fact, road constructing government organisations should have employed a team of experts (geotechnical engineer, geologist, hydrologist, economist, sociologist) permanently through the Public Service Commission. The experts' team should then be made responsible for all the disasters happening within their working areas. It is regrettable that currently these experts are lacking in the concerned organisations.
Slope stabilization techniques: One of the most effective ways to reduce the risk of landslides is by using slope stabilisation techniques, which depend on the type of landslide. Retaining walls can be constructed to hold back loose soil and prevent it from sliding onto the road. In areas with cracked bedrock, rock bolting can be applied, where bolts are drilled into the rock to hold it together and stop it from falling. Another option is bioengineering, which involves planting deep-rooted vegetation to stabilize the soil and prevent erosion.
Early warning systems: Sensors can be placed on unstable slopes to detect any movement, and drones can be used to regularly survey areas prone to landslides. By keeping track of changes in slope stability, authorities can
give early warnings and take steps to prevent disasters before they happen.
Effective drainage system: One of the main causes of landslides is water seeping into unstable slopes. Often, inadequate drainage systems along highways let rainwater build up and soak into the soil, increasing the risk of landslides. Engineers and geologists should design roads with effective drainage channels that guide water away from weak slopes. This helps prevent the water from weakening the soil. In fact, there should be someone to monitor the roadside drainage constantly so that the drainage will not be blocked by debris, and water can flow without any hindrance.
Tunnel construction as a safer alternative: In highly dangerous areas like the Narayanghat-Mugling section, where landslides happen often, constructing tunnels through the mountains could provide a more lasting solution.
Nepal is not alone in facing landslide challenges; other mountainous regions, such as the Alps in Europe and the Andes in South America, have developed innovative solutions to mitigate these risks. For example, Switzerland employs a combination of rockfall barriers, tunnels and extensive slope monitoring to maintain the safety of its mountain roads. By adapting these successful strategies to Nepal's unique environment, the resilience of its roadways could be significantly enhanced.
Policymakers and local government officials must prioritize road safety by requiring thorough geological assessments for all major infrastructure projects, particularly in landslide-prone areas. Local governmental bodies should heed the expertise of engineers and geologists when constructing or widening roads. By focusing on long-term solutions rather than temporary fixes, we can reduce the frequency of landslides and save lives.
Rai is a geologist currently working in the field of disaster risk management
