- The Srinagar-Jammu Nationwide Freeway, the area’s primary arterial highway, is among the many most landslide-prone highways within the Himalayas.
- A brand new examine which included subject surveys and a rock-mass evaluation factors to unstable slopes, worsened by weak rocks, rainfall, and highway widening.
- Specialists name for slope re-profiling, drainage, tunnelling, protecting limitations and climate-linked monitoring to scale back dangers.
The Srinagar-Jammu Nationwide Freeway (NH-44), the area’s primary arterial highway which runs from Jawahar Tunnel Banihal to Ramban within the Kashmir Himalayas, is among the many most landslide-prone roads within the Himalayas. Weak rocks and steep slopes that crumble simply beneath heavy rainfall make the freeway significantly fragile. A new examine assesses the slope stability of assorted highway minimize slopes alongside NH-44 and identifies slopes starting from reasonably steady to unstable, that are vulnerable to instability and collapse.
Slicing throughout the Pir Panjal vary of the North-Western Himalayas, the NH-44 passes by means of mountains which are “younger, fragile, and extremely fractured,” says Mehjoor Lone, and earth scientist at Northumbria College. “The rocks are weak, stuffed with cracks, and sometimes oriented in ways in which make giant blocks vulnerable to sliding out as soon as the slopes are minimize. Street development has additional left behind steep partitions, and when heavy rainfall seeps into the cracks, the rocks lose power and collapse. This pure fragility makes the freeway extremely vulnerable to landslides.” Lone explains. The examine additionally notes that the area lies inside a tectonically energetic zone, making the slopes inherently unstable.
Information exhibits that between 1990 and 2020, round 960 landslide occasions had been recorded alongside NH-44, killing 1,000 individuals and injuring 267 others. Furthermore, of the area’s 20 districts, 16 face comparatively excessive landslide threat and endure associated social and financial injury.
The brand new examine printed within the journal Utilized Geomatics in June this yr, examined 27 highway minimize slopes for power by means of rock mass ranking (RMR) and slope mass ranking (SMR), and carried out kinematic analyses at 48 websites.
How scientists mapped NH-44’s most unstable slopes
“Step one to evaluate slope stability was to measure the rock mass high quality utilizing RMR and SMR, that are commonplace strategies to guage how sturdy or weak a rock slope is,” says Riyaz Mir, Scientist C on the Nationwide Institute of Hydrology, Western Himalayan Regional Centre, Jammu, and a corresponding writer of the examine. “We then carried out kinematic evaluation to see how the cracks, joints, and layering in rocks might result in various kinds of failures comparable to sliding, toppling, or wedge collapse.”
To establish essentially the most weak spots, the researchers divided the freeway into 4 litho-structural domains (D1 to D4) primarily based on rock sort and construction. At dozens of web sites, detailed subject surveys, mapping, and measurements had been carried out. Weak zones, comparable to slopes made of sentimental rocks like slates, phyllite, or weathered gneiss, with poor drainage or unfavourable rock joints, had been marked as high-risk areas. “This mix of ranking methods, subject surveys, and structural evaluation helped establish essentially the most unstable places, the place landslides or rockfalls are more than likely to happen,” Mir notes.
Mir highlighted that in comparison with highways in Himachal Pradesh and Uttarakhand, NH-44 faces slope failures extra usually and with better depth, particularly through the wet season.
“The issue is made worse by ongoing highway widening works and heavy visitors,” he provides. “Whereas roads like NH-7 in Uttarakhand or NH-305 in Himachal are additionally dangerous, NH-44 is extra harmful owing to its lengthy unstable zones and its significance as the one all-weather lifeline to the Kashmir Valley.” Mir additionally notes that some places such because the Cafeteria Morh close to Ramban, stay energetic landslide zones, the place rocks and particles fall all year long, even on sunny days. “Total, the stretch from the Nashri Tunnel to Panthya-Ramsu is very weak to frequent landslide exercise.”
In the meantime, Lone, who shouldn’t be related to the examine shares, “It (the examine) identifies essentially the most harmful places and suggests sensible options comparable to re-profiling slopes, rock bolting, and higher drainage. This makes it a helpful information for engineers engaged on floor. Future work must be complemented with local weather and hydrological research, in addition to steady slope monitoring, to supply a whole threat administration framework.” Lone mentioned.
Nadia Mubarak, a senior analysis fellow on the Division of Earthquake Engineering, IIT Roorkee, additionally not related to the examine, states that it makes a well timed and invaluable contribution to understanding landslide hazards alongside one of the vital essential transport corridors within the area. “By combining SMR and kinematic evaluation with Geographic Data Methods (GIS)-based mapping, the authors present a scientific framework for figuring out and prioritising unstable slope sections,” she added. “That is significantly necessary within the Kashmir Himalaya, the place fragile lithology, steep gradients, and intense development exercise converge to intensify landslide dangers.”
Mubarak additionally notes that one of many examine’s primary strengths is its field-based methodology and its concentrate on producing actionable outcomes for infrastructure planning and mitigation. “By figuring out particular slope sections with reasonable to excessive susceptibility, the analysis affords clear sensible implications, permitting engineers and policymakers to focus on interventions extra successfully. Nevertheless, the methodology does have its limitations.”
Kinematic evaluation appears solely on the form of slopes and the best way rocks are organized, however it doesn’t absolutely seize dynamic triggers comparable to heavy rainfall, snowmelt, or earthquakes, elements that always trigger slope failures within the Himalayas. “Equally, whereas the paper highlights the function of anthropogenic drivers comparable to excavation and highway widening, these impacts will not be quantified in depth, leaving some uncertainty in separating pure versus human-induced influences,” Mubarak emphasises.
Freeway on the sting
Specialists warn that highway widening and tunnelling considerably disturb slope stability. Widening makes slopes steeper and extra unstable, and blasting throughout development creates new cracks within the rocks.
“Careless dumping of particles provides further weight and blocks pure drainage channels, additional destabilising slopes. “Tunnel entrances additionally weaken the encircling rocks, which might fail until instant assist is offered. These actions, if not managed fastidiously, worsen an already fragile state of affairs.” Lone says.
Mubarak provides that these disturbances have additional facilitated enhanced rainfall infiltration, elevated pore-water pressures, and progressive weakening of already fractured and weathered rock plenty.
The final two months have been a stark reminder of how local weather change is reshaping the Himalayas, with catastrophic occasions unfolding in Uttarakhand, Jammu and Kashmir, and throughout the border in Pakistan. In August, cloudbursts, landslides, and flash floods throughout Kishtwar, Kathua, Reasi, and Ramban districts in Jammu claimed 130 lives. The deluge peaked on August 26-27, when heavy rain triggered flash floods in Jammu and its surrounding plains, damaging infrastructure and homes, leaving 1000’s homeless and displaced.
“Within the Kashmir Himalayas, the impression is especially seen within the type of rising landslide dangers,” Lone says. He added that rainfall patterns have modified. “We’re witnessing a shift from regular seasonal rains to sudden cloudbursts and very heavy downpours, the place a month’s rainfall can happen in only a day or two. Slopes saturated with water shortly lose stability. “Melting glaciers and shrinking snow cowl are additionally altering river flows throughout the Himalayan areas and, in some circumstances, triggering sudden floods and slope failures.” Lone additional provides that excessive climate occasions are actually occurring extra often, with shorter gaps between them, giving slopes little time to get well. “All of this provides to the pure fragility of NH-44.”
Engineering challenges and options
Working in a tectonically energetic and landslide-prone area presents persistent challenges for freeway engineering. The mixture of frequent rainfall, steep and variable topography, and extremely fractured rock plenty considerably heightens landslide susceptibility, immediately affecting highway security, development prices, and mission timelines. Mubarak states that guaranteeing slope stability requires steady geotechnical monitoring and adaptive design approaches that may reply to altering floor circumstances. “As well as, sustaining dependable connectivity is a significant concern, as slope failures usually result in extended closures.”
Lone notes that step one to stop landslides alongside the freeway is to reshape the harmful slopes into safer angles moderately than leaving them vertical. “Weak slopes have to be supported with rock bolts, wire mesh, and concrete spray, with retaining partitions the place mandatory,” he says. “Correct drainage is completely essential as each floor and subsurface drains have to be constructed and recurrently maintained. Protecting limitations comparable to rockfall nets and catch fences can assist preserve falling particles off the highway.”
He provides that the rain gauges and slope monitoring methods must be put in to offer early warnings, in order that authorities can quickly shut the freeway when rainfall crosses hazard limits. “Future infrastructure growth within the Himalayas also needs to concentrate on higher slope administration, combining engineering works with bioengineering strategies comparable to planting deep-rooted vegetation to carry the soil collectively and stop erosion.”
The consultants additional stress that neighborhood engagement and public consciousness is equally necessary. Individuals dwelling close to the freeway must be knowledgeable about energetic landslide zones and safer areas for housing, farming, and growth. Mir states that any scientific findings have to be shared shortly with native communities to allow them to plan land use extra safely. “The native authorities authorities ought to be certain that analysis and threat info attain individuals instantly to scale back threats and construct resilience.”
A senior official on the Nationwide Highways and Infrastructure Growth Company Restricted (NHIDCL), on situation of anonymity, shares that the high-risk stretches of the freeway embody Panthal, Ramban, Digdol, and Khooni Nallah. The supply, additionally a website engineer, requested anonymity as they had been talking instead of the engineer liable for this part of the freeway, who was unavailable for a remark. “For slope stabilisation, measures comparable to rock anchors, self-drilling anchor bars and wire mesh have been put in. For the reason that rock high quality within the space is poor, tunnelling has confirmed to be the best resolution for managing landslides. The frequency of such incidents has already lowered considerably as a result of tunnel development,” they add.
Learn extra: The highway to highway resilience is paved with aware development and design say consultants
Banner picture: The dangers of working in a tectonically energetic and landslide-prone area are heightened by rainfall, steep and variable topography, and extremely fractured rock plenty. These result in larger landslide susceptibility, immediately affecting highway security, development prices, and mission timelines. Picture by NHIDCL.
