Massive Land Subsidence in Ramban, J&K - Expert weighs in

Last month, on April 28th, a major land subsidence incident occurred in Pernote village in Ramban district. The incident destroyed over 60 houses and forced the evacuation of more than 500 people by the administration to safer places. In the last year, at least two major land subsidence events have been reported in the region: in Doda and recently in Ramban. Land subsidence, the gradual sinking of the earth's surface due to any abrupt downward movement, has become one of the major environmental concerns in Jammu and Kashmir in recent years. 

Jammu-Kashmir is a part of the great Himalayan mountain system & is characterised by its complex geological vulnerabilities including tectonic activities and seismic hazards. This has brought back focus on the fragility of the Pir Panjal mountains lining the region. In the last two decades or so, the mountains in the region have undergone large-scale blasting and tunnelling to make way for the widening of the National Highway (NH) 44 and the extension of the railway line from Udhampur to Kashmir Valley.  Over the years, several mountains were bored to make scores of tunnels for the strategic railway line, which is touted as a ‘game changer’ connecting the region to the massive Indian Railways network.

However, the project, along with the four lanning of the national highway, has sparked concerns about their impact on the ecology of the Pir Panjal range. Locals have often alleged that the blasting of mountains has made the range unstable, causing landslides and incidences of land subsidence. Not just J&K, but land subsidence hogged headlines last year when a small Himalayan pilgrim town, Joshimath in Uttarakhand, was reported to be sinking. The sinking caused damage to hundreds of houses in the township.

Is land subsidence natural?

A paper published in the International Journal of Earth Sciences in 2018 titled ‘Geological and geotechnical challenges in road widening, national highway: 44: Jammu-Udhampur-Banihal-Qazigund, J&K, India’ noted that many factors, such as irrigation of agricultural land, deforestation, and slope excavation for construction activities, had disturbed the natural hill slope and generated a temporary slide zone, sometimes activating the old landslide as well. 

“Construction of approach road, Preparation of portal, water seepage, shear zone, rock settlement or rock bursting, vibration and noise, tunnel support system, joint orientation are major problems which are likely to be faced... Sometimes actual geological conditions are much different from prediction, based on geological and geotechnical investigations. The changes in rock class, water encounters, and settlements are called geological surprises that affect the work progress. For long-length tunnels, ventilation is also an important factor. The proposed tunnel at Peera to Chandrakote will cross the Murree thrust and construction of the tunnel in this section would be challenging”, it had further noted.

On the other hand, experts say that the phenomenon of land subsidence is natural. However, it can be exacerbated by human activities like excessive pumping of underground water, unplanned construction and improper land use practices. 

Kashmir-based earth scientist Dr Riyaz Ahmad Mir who has researched extensively on landsliding, slope stability and hydrogeochemistry, said that the main cause of land subsidence is groundwater extraction. “The groundwater covers a space under the soil. When we extract that water the space gets empty, leaving no support to that patch of land leading to its sinking.”

“Similarly, in the process of tunnelling the caves or the tunnels are often left empty. If the support inside the tunnels and the strength of the land above can't handle the weight, the land tends to subside normally. These are mostly the major causes of land subsidence,” he further noted.

Reasons behind Ramban

Referring to the recent incident of subsidence at the Parnote area of Ramban, he said Parnote is a mega landslide zone. “The area is located on a hill slope and the subsidence that is happening is a landslide. It is demarcated as a complex type of landslide and subsidence zone.”

Mir emphasised that the accumulation of water is one of the primary causes contributing to land subsidence in Parnote. “The soil there is considered as water sensitive and whenever there is heavy rainfall, the soil accumulates the rainwater beyond its capacity and loses its strength, which leads to the instability of land.”

He further highlighted unplanned construction, deforestation and lack of water drainage system, among other causes. “All these factors make the area more susceptible to landslides and subsidence.” 

He said that the area is close to a major geological thrust zone also known as the Main Boundary Thrust (MBT). It is a prominent large-scale fault zone within the Himalayas where the huge deformation of even compact rock formations is taking place.

“Because of the MBT, the hard rocks get fractured, pulverised and weak. So when there is any fracture or fault zone nearby, the rock formation is also weak in that area. The forest cover normally stabilises the steep or mountain slopes but because of deforestation these stable slopes also get weak increasing the chances of landslide.”

He explained that the unplanned construction of multi-story houses could also be a plausible causal factor because they increase the load on the already weak land. 

“The area is a high elevated slope with thick water sensitive soil cover, near to a major thrust zone, construction is mostly unplanned, there is no proper water drainage system, these all things make the area more susceptible to landslides or land subsidence.”

What can we do?

He also said that the government agencies had been working on landslide disasters in the area. But, the primary responsibility lies on people's shoulders as to how they follow the laid-out guidelines and recommendations of these studies. 

“This area is prone to landslide initiation or occurrence because of the natural as well as human factors,” he added. 

He emphasised a need to create mass awareness on the ground about tackling such issues and making people understand the topography, landslide susceptibility and geomorphology of the land they operate upon.

Keep Reading

• GR Interview: How Chewang Norphel's Artificial Glaciers Quench Ladakh's Thirst
• Indore’s residential society saves Rs 5 lakh a month, through rainwater harvesting
• PM Matsya Sampada Yojana falling short in Bhopal?
• Machora, Tikamgarh: Women struggle in water scare village and await better policies

Follow Ground Report for Environmental News From India. Connect with us on Facebook, Twitter, Koo App, Instagram, Whatsapp and YouTube. Write us on [email protected] and subscribe our free newsletter.