Context: Eight renowned institutions in India conducted independent investigations to uncover the factors contributing to land subsidence in Joshimath, Uttarakhand. Their findings suggest that seismic activities, construction deficiencies, population density, inadequate drainage systems, and various other factors are ‘potential’ contributors to the sinking of this Himalayan town.
- The town of Joshimath is also nicknamed as Jyotirmath and is the winter seat of Lord Badri, whose idol is brought down from Badrinath temple to Vasudeva temple at Joshimath.
- It is situated on Vaikrita groups of rocks overlain by morainic deposits which are composed of irregular boulders and clay of varying thickness.
- This holy town is revered by the Hindus for being an important pilgrimage center of the country. Alaknanda and Dhauliganga meet at the confluence of Vishnuprayag overlooking the town of Joshimath.
According to the National Oceanic and Atmospheric Administration (NOAA), subsidence is the “sinking of the ground because of underground material movement”. It can happen for a host of reasons, man-made or natural, such as the removal of water, oil, or natural resources, along with mining activities. Earthquakes, soil erosion, and soil compaction are also some of the well-known causes of subsidence.
Reasons for sinking of Joshimath town
A variety of factors both anthropogenic and natural have led to the subsidence of Joshimath:
- Joshimath’s vulnerable foundations: it was developed on the debris of a landslide triggered by an earthquake more than a century ago.
- High intensity seismic zone: more prone to earthquakes besides gradual weathering and water percolation which reduce the cohesive strength of the rocks over time.
- Vulnerability to disasters: Himalayan rivers, heavy rainfall, toe cutting phenomenon, flash floods and cloudbursts further worsen the situation.
- Demographic load: High population pressure and Haphazard construction activities have led to cracks appearing in the houses there.
- Blocking of natural flow of water: Moreover, the lack of a proper drainage system might have also contributed to the sinking of the area. Experts say that unplanned and unauthorised construction has led to the blocking of the natural flow of water, which eventually results in frequent landslides.
- Infrastructure build-up: NTPC’s Tapovan Vishnugad Hydropower Plant is a 520 MW run-of-river hydroelectric project being constructed on Dhauliganga River in Chamoli District of Uttarakhand. Run-of-river hydro projects use the natural downward flow of rivers and micro turbine generators to capture the kinetic energy carried by water. Typically water is taken from the river at a high point and diverted to a channel, pipeline, or pressurised pipeline (or penstock).
- Internal erosion caused by the subsurface drainage, which may be due to infiltration of rainwater/ melting of ice/ wastewater discharge from household and hotels, plays crucial role in the subsidence of Joshimath town. #As per IIT Roorkee Report.
Warnings in past
The first warning signs were sounded about 46 years ago in the M C Mishra committee report that had highlighted the dangers of unplanned development in this area, and identified the natural vulnerabilities. D P Dobhal, a glaciologist, said the area was once under glaciers. The soil is, therefore, not ideal for large constructions.
- Control the infiltration of water into construction sites, buildings, or other sensitive areas. It can include techniques such as proper drainage systems, waterproofing, and the use of barriers to prevent groundwater or rainwater from seeping into unwanted areas.
- Stop Blasting activities in the vicinity of disaster prone zones like Himalayas. As blasting can lead to potential hazards like ground vibrations, which can damage nearby structures or ecosystems. #recommended by the State Disaster Management Department.
- Adherence to National Building Code of India, 2016 ensures that construction projects meet safety, structural, and environmental standards. It covers various aspects of construction, including design, materials, construction methods, and occupancy requirements.
- Conducting a thorough Environmental Impact Assessment (EIA) before any construction project to assess its potential environmental impacts and implementing measures to mitigate or minimize these impacts.
- Involving local communities and stakeholders in the planning and decision-making process for construction projects to address their concerns and ensure social responsibility.
The sinking of Joshimath serves as a stark reminder of the delicate equilibrium that must be maintained in ecologically sensitive regions, where human activities interact intimately with the forces of nature. Through careful planning, sustainable practices, and collective responsibility we can protect and rejuvenate this sacred town and other vulnerable areas like it across the Himalayan landscape.