Environment

Why Jammu-Srinagar national highway is so landslide prone

Most of the hills around Jammu-Srinagar highway were rocky and barren and any disturbance — natural or anthropogenic (man-made) — wrecked havoc

 
By Bilal Bashir Bhat
Last Updated: Friday 13 March 2020
Governments have failed to find alternatives to the crises that result from the closure of the Jammu-Srinagar highway Photo: Wikimedia Commons

The Jammu-Srinagar highway — a vital surface link between Kashmir and rest of the world — was closed due to heavy landslides that resulted in stranding of several thousand passengers and vehicles.

Several people have lost their lives on this road because of landslides which occur mainly from man-made activities.

The frequent closure of the road causes not just death, but also countless misery and pain on the people of the Kashmir valley.

The unscientific manner with which trees were cut on the Pir-Panjal range, along with machine vibrations, utilised for widening the Jammu-Srinagar highway are just some of these activities that take place.

These activities alter pressure under slopes, leading to instability. This causes landslide to occur.

Development is good but is disastrous for everybody when it occurs in an unscientific manner.

The Pir Panjal range is geo-morphologically different from the rest of the district ranges because it is a plateau. This geomorphic unit, together with a tropical climate, allows for the formation of a thick column of soil.

Steep slopes are the second-most consequential conditioning factor in this range.

Slopes even at a 15-degree angle are prone to landslides. At yet incrementing angles, the pressure on soil and other unconsolidated matter increases. Such areas optically discerned a high frequency of landslides.

Most of the hills around Jammu-Srinagar highway were rocky and barren and any disturbance — natural or anthropogenic (man-made) — wrecked havoc in the region.

The utilisation of machines —used for hill cutting — results in the loosening of soil from vibrations.

Steep slopes — from the hill cutting —gradually widen fractures on the hills. Water is accumulated in these fractures, resulting in landslides.

When components of a hill are cut down, joints of stones and soil — not firmly fixed to each other — separate and subsequently collapse during heavy rain.

Vibrations from heavy equipment — along with natural factors — decrease the strength of the hills, resulting in them becoming more prone to landslides.

Over the past few years — with the increase in construction and widening of the highway and tunnels — incidents of landslides increased.

Perpetual kineticism from heavy vehicular traffic is another cause of landslides in the regions around Jammu-Srinagar highway.

Governments have failed to find alternatives to the crises that result from the closure of the Jammu-Srinagar highway in the 70-plus history of the Kashmir Valley.

Factors that influence landslides are of two types: Conditioning and triggering factors.

Conditioning factors usually have to do with the terrain — such as the soil, geology, land use, drainage and groundwater.

Triggering factors are direct causes that influence landslides: Rainfall, earthquakes and man-made activities fall under this type.

Man-made activities include water leakage from utilities, excavation of slope or its tow, loading of slope or its crest, the drawdown of reservoirs, irrigation, mining, artificial vibration and deforestation.

Mitigation

Landslide mitigation refers to several man-made activities on slopes with the goal of lessening the effect of landslides.

Landslides can be triggered by many concomitant causes.

In addition to shallow erosion or reduction of shear strength caused by seasonal rainfall, landslides may be triggered by man-made activities like adding excessive weight above slopes, digging at mid-slope or at the foot of the slope.

Often, individual phenomenon join together to generate instability over time: This often does not allow a reconstruction of the evolution of a particular landslide.

Thus, landslide hazard mitigation measures are generally not classified according to the phenomenon that might cause a landslide. Instead, they are classified by the sort of slope-stabilisation method used:

  • Afforestation: Afforestation programmes should be taken up immediately in the hills, as trees has the capacity to attach soil firmly together, reducing chances of landslides in these regions.
  • Geometric methods: The geometry of the hillside is changed (in general the slope).
  • Hydrogeological methods: An attempt is made to lower groundwater levels or to reduce the water content of the material.
  • Proper drainage facilities in these regions is another way to reduce the chances of landslides.
  • Chemical and mechanical methods: Attempts are made to increase the sheer strength of the unstable mass or to introduce active external forces (anchors, rock or ground nailing) or passive (structural wells, piles or reinforced ground) to counteract destabilising forces.
  • Establishment of local monitoring and emergency response systems
  • Education and awareness about the impact of landslides: Each of these methods vary somewhat with the type of material that makes up the slope.

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