Climate & Environment
Expansion likely reason for more landslides on Muglin-Narayangadh road, experts say
It was expanded three years ago and measures to avert landslides may not have been taken. As the section is an artery of the economy, losses total hundreds of millions.Chandan Kumar Mandal & Ramesh Kumar Paudel
On the night of June 30, there was a landslide five kilometres from Muglin on the Muglin-Narayangadh road. The next day, on July 1, another landslide was reported one kilometre north of there and several other small landslides in different locations nearby. In the evening there was another massive landslide 14 kilometres from Narayangadh and a huge boulder came rolling down on the road.
With the onset of monsoon, the Muglin-Narayangadh road has once again witnessed a series of landslides frequently hindering vehicular movement for hours as well as posing a threat to the general public with the falling debris.
Social media is full of pictures and videos of vehicles trying to cross sections of the road hit by landslides and vehicles have been even hit by falling debris.
Landslides along the road causing disruptions in vehicular movement are nothing new.
“Although landslides have been a common problem for this road section, it has only got worse in the last six years,” said Govinda Lal Shrestha, a truck driver who has been plying the route for the last 12 years, told the Post. “Last week, I was en route to Banepa from Bara, but it took me three days to cross the Muglin-Narayangadh section, after a landslide at Setidovan.”
At other times loaded trucks take at most six hours to cross the section.
“It seems the ongoing problem will remain for at least a week,” said Shiva Khanal, information officer with the Division Roads Office, at Bharatpur, Chitwan. “As long as we do not dig out all the wet soil accumulated on the edge of hills on the roadside, landslides are unlikely to stop.”
The biggest obstacle has been caused by the landslide of July 2, at Setidovan near Bhorle—20km from Naraynagadh.
Although landslides at other places have been cleared for vehicular movement, Setidovan landslides have been causing roadblocks regularly.
With three months of the monsoon still remaining, even if it is cleared it seems that vehicular movement could continue to be affected throughout the rainy season.
The problem of landslides on the road seems to have been aggravated with its widening.
In a bid to upgrade the 33.2km road to Asian Highway standard, it was expanded to a width of 9 to 11 metres from 5 to 5.5 metres.
The Muglin-Narayangadh Road Widening Project, supported by the World Bank, also aimed to address road safety and facilitate express movement of vehicles and environmental sustainability issues along the trade corridor. It was completed in 2018 against the initial deadline of 2015.
Shrestha, the truck driver, is right in saying that the situation has got worse for vehicular traffic in the last six years as there were frequent roadblocks during the expansion and in the three years since its completion.
Rainfall-triggered landslides at different locations have remained unsolved.
Experts have long pointed out that measures to avert landslides along the road section were not adequately implemented during road expansion.
“Although I have not visited the site recently, photos and videos of landslides from the ground show that the risk of hydrometeorological hazards, which could occur due to heavy rain, was not properly considered during the project,” Basanta Raj Adhikari, an engineering geologist, who is currently in China, told the Post over the phone.
“While cutting the slope for road expansion, potential risk of landslides at different areas considering the amount of rainfall should have been identified. Surface to underground water management should also have been taken care of. While cutting the slope, we should also consider what degree of slope slicing will leave the ground stabilised and then design accordingly.”
Patterns of landslides show these measures were not correctly enforced while the road was being upgraded, according to Adhikari.
While the road was widened adjacent hills were sliced down at several places. Nearly Rs3 billion was spent on the road expansion project. The road ultimately got wider but landslides regularly block it during the monsoon. The project had also identified 32 landslide-prone areas, and an additional Rs300 million was spent on preventing landslides.
According to another engineering geologist, Ranjan Kumar Dahal, not much has been done to minimise the risk of such landslides permanently.
“Authorities have been mostly on the ‘wait and watch’ mode while dealing with landslides along the road section,” said Dahal, also an associate professor with the Central Department of Geology, Tribhuvan University. “We do something for one year and rejoice that landslides have been managed only for them to occur again the following year.”
Dahal, with expertise on landslides, debris flow, earthquake, disaster management, engineering geology of roads and dams, also points out that site-appropriate design was not carried out.
“Slope stabilisation was also not done properly and bio-engineering measures for slope stabilisation were not implemented,” said Dahal. “Here, people have thought that once the slope is cut, then it naturally stabilises after some time. However, it does not happen in our country due to our topography.”
But project officials say they have implemented measures for controlling landslides along the road section.
“We have worked on all sites where landslides had occurred after cutting the slopes. Last year, a landslide fell at a place four kilometres towards Narayngadh from Muglin while work was still ongoing,” said Sabina Ranabhat, an engineer and information officer for the Muglin-Narayangadh Road Expansion Project. “Even at that location, we have worked on controlling old landslides, although we have not begun to manage recent landslides. This year, landslides at the same spot have caused significant trouble. The rest of the landslides seen this time are new.”
This year, landslides at Setidovan have been a major headache for the authorities as it is one of the spots where landslides were not reported in the past.
According to Khanal, the information officer, Setidovan area was not touched while expanding the road.
Local residents have been farming in the area where landslips have occurred this time.
“I have been farming for 25-30 years there but I never saw any landslides,” said Rom Bahadur Gurung of Setidovan.
Apparently, it is not only rainwater that is a hazard.
According to Khanal, water from an underground spring has burst and water from it has been flowing along the road wall, leaving the whole sidewall wet at Setidovan.
Whatever the reason for the landslides, experts stress the need for finding a long-term solution to landslides occurring at the road section, which is one of the major trade routes of the country connecting Kathmandu with western Nepal and the East-West Highway.
“It seems something is still wrong there. The stakeholders need to dig out the details of whether the issue is in construction or monitoring efforts,” said Adhikari, who is also an assistant professor at the Institute of Engineering, Tribhuvan University.
Obstruction in vehicular movement along the section, which sees nearly 10,000 vehicles every day, disrupts essential supplies to Kathmandu Valley among other places. Even this week, vehicles carrying food items and fuel had been stuck around Bharatpur and the eastern parts of Chitwan.
According to Dahal, the ongoing traffic blockade along the road section has already caused losses worth Rs1 billion.
“We have estimated that if the vehicular movement along the section is obstructed for 18 hours, the economic loss would be around Rs210 million,” said Dahal. “Authorities may take pride in saying that their efforts backed by some resources have stopped landslides. However, the economic losses caused by the landslides that obstruct vehicular movement are much bigger.”
Dahal said the stakeholders need to first honestly re-evaluate efforts made so far to mitigate landslides along the section so that the problem can be handled in a new manner.
“We have not been able to think innovatively while dealing with the landslides along the section. We are somehow stuck with conservative ideas,” said Dahal. “Earlier we did not have enough budget and technology, but now we do. If needed, required support should be sought from elsewhere too. If we do not have good roads, then how can we even imagine achieving economic prosperity?”
Dahal, the engineering geologist, suggested the authorities build ramp structures above the adjacent hills which will prevent debris from falling on the road.
“Ramps can hold off debris falling and accumulate them so that vehicles plying the road below will not be hit,” said Dahal. “Even if it takes Rs40-50 million, the authorities should invest in it.”
On Friday, vehicular movement along the road was eased after vehicles stuck on Thursday had passed. However, the fear of landslides is not over yet.
“As the debris and rocks stuck on the hills are falling at their own pace, it would take some time for all of them to come down on the road. We have seen layers of hard rock beneath the topsoil, so when all the debris comes down, we can hope there will not be any more landslides or at least major obstacles,” said Khanal.
“However, we cannot leave that area as it is. We have written to the Department of Roads asking what should be done to avert more landslides and also informing them that we cannot do more with our capacity.”
People often ignore the risk of being hit by the falling debris and drive across the landslide causing some accidents. Debris piled up against the wall and stones lying in the middle of the road cannot be cleared easily with the existing human resource and equipment.
The importance of the Muglin-Narayangadh road cannot be overemphasised.
“The section is part of the strategic road network, and the road expansion project itself was a significant endeavour of the Nepal government and a development partner,” said Adhikari, the engineering geologist. “Lapses in mitigating landslides should not have happened. Measures must be prioritised and monitored regularly.”