Why India's Himalayan city Joshimath is sinking

Joshimath is a Himalayan town located on a hill slope, and sits on the debris of an old landslide, at an altitude of 6,151 feet. Among debris and falling walls, the condemned houses of Joshimath now have the air of a ghost town.

The small town is the gateway to revered Hindu and Sikh shrines and a popular stop for trekkers and skiers drawn to nearby slopes when it snows. Recent years have seen a boom in construction activity.

Until this month, bulldozers were being used to widen the road to the town to improve access. Following the protests of recent weeks, the roadworks were halted.

Sinking upto 14 cm

Slow sinking of land up to 9 cm is recorded in Joshimath town over seven months, between April and November 2022, according to the Indian Space Research Organisation (ISRO) satellite-based report. However, between December 27, 2022, and January 8, 2023, the intensity of land subsidence increased and the town sank by 5.4 cm in these 12 days.

National Remote Sensing Centre, ISRO said several reports over the last few days highlighted the subsidence occurring in Joshimath.

Due to landslide-related creep, cracks have appeared in around 700 houses. Roads along with the hotels and hospitals present there have developed cracks, said NRSC.

The region subsided around 5 cm within a span of a few days and the areal extent of subsidence has also increased. But it is confined to the central part of Joshimath town, said the space agency of India.

A subsidence zone resembling a generic landslide shape was identified (tapered top and fanning out at base). The Crown of the subsidence is located near Joshimath-Auli road at a height of 2,180 metres, said ISRO report.

Sinking occurred in 1970 also

Cracks and signs of sinking also appeared in Joshimath in the 1970s, but the scale of the damage is far greater this time, experts familiar with the topography said.

Officials and geologists examining the damage in Joshimath think the flash floods in 2021 that washed away the Rishiganga mini-hydropower project and claimed nearly 200 lives - were the trigger to Joshimath's present-day troubles.

"Reports of cracks in homes started then," said Swapnamita Choudhury Vaideswaran, a scientist with the Dehradun-based Wadia Institute of Himalayan Geology, a research organisation, to Reuters.

People displaced, buildings demolished

Local authorities have moved about 200 families to lodges, hotels, schools and the city council building for safety, marking 128 of about 4,500 buildings with a red cross, indicating they are unsafe to inhabit.

Two hotels that had developed cracks are being demolished to avert the risk of their possible collapse, officials said.

Families that own the crumbling properties have shifted the elderly, women and children to villages or towns where they have relatives, while the men have stayed back to negotiate compensation with the district administration.

Scientific teams have fanned out across Joshimath to study the structural stability of houses, assessing damage and investigating the source of a gush of muddy water pouring out of a drain since the cracks appeared.

Many property owners living in shelters return to their homes every day to assess the damage or simply try to come to terms with their losses.

Rishi Devi, 50, wiped away a tear outside her home as she recalled entering it as a new bride. "This is our ancestral home, and now it's gone," she said, showing the rooms in ruins, with beams falling off and cracks uprooting the house from its foundation.

The entire Joshimath may sink: Report

The National Remote Sensing Centre (NRSC) of the Indian Space Research Organisation (ISRO) has released satellite images of Joshimath and a preliminary report on land subsidence which shows that the entire town may sink.

The pictures are taken from the Cartosat-2S satellite. Hyderabad-based NRSC has released satellite images of areas that are sinking.

In images, the entire town, including the Army's helipad and the Narasimha temple, has been marked as a sensitive zone.

The satellite images show that the Joshimath-Auli road is also going to collapse due to land subsidence.

Although scientists are still studying the cracks that appeared in the houses and roads after the land subsidence in the town, the findings in the primary report of ISRO are frightening.

Joshimath is a warning sign

The town is a warning sign, experts say, not just for India but for the entire Himalayan Hindu Kush mountain region, part of what has been called the "Third Pole," which contains the world's third-largest repository of glacial ice. The Third Pole spans more than half a dozen countries, including China, and is critical to the fate of more than a billion people.

More than 700 homes in Joshimath, a town of about 22,000 people, have developed cracks. Construction in the area, some 320 miles northeast of India's capital, New Delhi, was halted this week. The chief minister of Uttarakhand state, where Joshimath is located, announced that cities would be audited to ensure they consider both ecological and economic needs.

In 2021, the area experienced a deadly flood after a section of rock and hanging glacier fell down a steep slope. That calamity was exacerbated as the floods encountered infrastructure barriers, picking up speed and debris and killing more than 80 people. Experts said climate change may have contributed to the disaster, and studies have found that glaciers in the Himalayas are melting dramatically, and at a much faster pace than during the 20th century.

There are many reasons that earth sinks, though it is typically the result of human activity. Land subsidence can occur when groundwater, which holds up land, is removed from certain rocks. When the water is gone, the rock "falls in on itself," writes the U.S. Geological Survey, which also notes that activities such as underground mining can contribute to the sinking.

"We are messing up our environment to an extent that is irreversible," said Anjal Prakash, who researches climate change and sustainability at the Indian School of Business in Hyderabad.

[Text: Reuters, ANI, IANS, Washington Post]