Experts have been time and again issuing dire warnings of mighty disasters if nothing is done to mitigate the alarming rise in global temperatures. Nowhere is this warning more relevant than in the mighty, yet fragile, Himalayan range of mountains, which has witnessed a phenomenal rise in weather-related calamities. For instance, the two states of Uttarakhand and Himachal Pradesh alone recorded over 170 incidents of landslides this year claiming scores of lives. In fact, the entire Himalayan region, right from the Pamir Knot and the Hindu Kush right up to Arunachal Pradesh, is vulnerable, geologists have indicated.

What is more worrying is rising frequency of landslide incidents. Uttarakhand, one of the most severely affected of the hill states, the past five years saw an astounding increase of 2900 per cent in the number of landslides. In 2015, as many as 33 landslides claimed 12 lives. This number rose to 972 landslide incidents in 2000, with 25 deaths. In all, since 2015, some 7,750 extreme rainfall events and cloud bursts have taken place in the state, killing 230 people. The neighbouring Himachal Pradesh saw this number double since last year.

Impacts of global climate change, coupled with generations of exploitation, unplanned and, at times, mindless development and a poor communication between the scientific community and its research with the local population and their traditional knowledge have proved to be a recipe for disaster.

Climate crisis

A TERI (The Energy and Resources Institute) report has noted that climate change had a strong influence on the precipitation over the Himalayas and the melting response of glaciers. This affects the runoff pattern of rivers that drain from the Himalayan catchments. These rivers are the source of life and livelihood of over 500 million people in the Indo-Gangetic plains and any variability in their pattern of flow can have far-reaching consequences.

Not only does this warming of high-altitude regions lead to loss of ice mass and receding glaciers, but erratic monsoons are also triggered. This, along with increased rainfall intensity in short durations, leads to deluge and landslides, causing extensive damage to property and lives.

According to data maintained by the disaster management authorities of Jammu and Kashmir, Himachal Pradesh and Uttarakhand, there has been an increase in the number of cloudburst and landslide incidents this year due to extreme rainfall events. As per the Indian Meteorological Department (IMD), rainfall in the last 20 days of July was around 110 per cent above normal in Himachal Pradesh, Uttarakhand and Jammu and Kashmir.

The Sixth Assessment Report by Inter-governmental Panel on Climate Change (IPCC), released on August 9, 2021, points to the effect of climate change on glaciers and snow cover in the Himalayas. “There has been a greater warming over the Hindukush Himalayas with fast depleting snow cover and retreating glaciers,” said R Krishnan, executive director, Indian Institute of Tropical Meteorology, Pune, the lead author on the chapter on water cycle and its changes in this report, compiled by 234 scientists from 64 countries.

Pointing out that receding glaciers is a phenomenon that is “locked in” and cannot be reversed, the report said the level of temperature rise in the mountains and glacial melt is unprecedented in 2,000 years. It warned that if greenhouse gas (GHG) emissions, blamed for global warming, do not fall, glaciers in the Hindukush Himalaya will decline by two-thirds. In fact, human activity and influence is blamed for the retreating of glaciers.

The report also pointed to a likely rise in landslide incidents such as the one faced by Chamoli in Uttarakhand, caused by a glacial break on Nanda Devi followed by flash floods in the region, earlier this year. “Extreme precipitation is projected to increase in major mountainous regions with potential cascading consequences of floods, landslides and lake outbursts in all scenarios,” the report pointed out.

Fragile topography

The Himalayan Range of mountains, the youngest as well as the tallest in the world, is convexed towards the south and is formed at the convergence of two tectonic plates ~ Eurasian Plate and the Indian Plate. The tectonic plates are moving at a rate of 50-55 mm per year, which causes considerable stress on the rocks, making them susceptible to landslides and earthquakes. Landslides, geologists say, is a natural phenomenon, where rocks and soil, loosened by erosion by rivers or torrential rains, slide down a hillside. Most landslides in the Himalayan region occur during the monsoon months of June to September. But they are intensified by unplanned construction and deforestation. In other words, the high seismic activity in the fragile Himalayan slopes and heavy rainfall leads to increased landslide incidents.

Around 15 per cent of India’s total landmass is vulnerable to landslides, according to the Geological Survey of India (GSI). Also, the National Disaster Management Authority lists the Himalayan states, Arakan-Yoma belt in the North-East, the Meghalaya plateau, Western Ghats and Nilgiri hills as the most landslide-prone areas.

Bending rules
Disasters and losses due to these incidents are rising every year, mainly because an ever-increasing number of people are occupying what can be termed as “hazardous areas” because of greater development. All settlements are located on landslide prone areas. The risks faced by people living in the mountains are not only due to the rugged topographical features but also embedded in patterns of human land use, activities and interactions. Development trends in modern states, influenced by market forces, cultural integration, rapid urbanization and globalization have all impacted the extent of disaster risk, say experts. Most frequently, development that is inappropriate both to the mountain context and the needs of the people are larger causes of losses than the rugged terrain and harsh climate in itself. When priority is given to economic growth, mountain landscapes and, therefore, risk-scapes, are modified through hydropower schemes, forestry and minerals exploitation, road construction and tourism. Even a normal to moderate rainfall is known to trigger landslides due to such unplanned development.

In Uttarakhand, apart from the multiple dams that have been built, the Char Dham Pariyojana (CDP) and the Rishikesh-Karnprayag Railway line project have seen severe damage to hill slopes, including deep cutting and felling of trees. A report by a Supreme Court appointed high-powered committee to monitor CDP, says about 700 hectares of forests have been lost, entailing felling of over 47,000 trees in the CDP alone.

Bane of mega projects

Environmentalists blame large development projects, including mega hydropower plants, for weakening the already fragile geology of the Himalayan region, making them vulnerable to earthquakes, landslides and flash floods.

While hydropower is seen as a “green” energy source, since it substitutes energy from fossil fuels, these projects could alter the ecology of a region, making them vulnerable. Himachal Pradesh, in particular, is striving to tap this hydropower source.

A campaign is underway in Kinnaur district of Himachal Pradesh against such mega hydropower projects. A scientific study estimated that tapping of the Sutlej River in the glacially-fed valley through all planned projects could impound nearly a quarter of the river water in dams and divert 72 per cent of the water through tunnels dug deep into the mountain-sides. On August 11, a massive landslide in Nigulsari village in this district killed 28 people and injured 13. A month earlier another landslide in this district killed nine tourists and damaged a bridge.

While a team from the Geological Survey of India (GSI) that visited the area following the disaster put it down to the steeply inclined slope and incessant rainfall, the villagers of Nigulsari and nearby Thatch are blaming the 1,500 MW Nathpa Jhakri Power Project on the Sutlej. A 27.4 km long headrace tunnel passes right under the villages. Residents of the villages say the landslide was a result of heavy explosions carried out during construction of the tunnel in late 1990.

Residents of five v1illages, affected by the project as well as a proposed 840 MW Jangi Thopan Pavri Hydro-electricity Project on the Sutlej in Kinnaur district, have grouped to form the “No Means No: movement to demand scrapping of all proposed hydropower projects in the region.

Policies matter
Every time a disaster strikes, one talks about what could have been done. Increasingly, risks are outcomes of planned developments in which the condition of mountain habitats and concerns of their inhabitants are ignored. In this scenario, disasters appear not as “unscheduled events” but as “collateral damage”, inevitable unplanned outcomes of prevailing strategies that make little or no effort to prevent them.
 Ironically, building codes exist but are never followed. Often, scientists say, building codes have been laid out for plains and these have been copied out for mountains, which does not work as the topography and soil conditions are completely different. There is need to map out settlements and devise building codes specific to mountains, they said.

Meanwhile, geologists and environmentalists are unanimous in pointing out that separate sets of disaster management methods need to be worked out. A greater coordination and use of local knowledge to respond would be of prime importance. With communication between various agencies being of prime importance in the event of any disaster, including earthquakes, experts agree that there needs to be coordinated information sharing and response mechanisms as well.

Above all, management of landslides requires a coordinated and multi-faceted approach among many stakeholders strengthened by the requisite operational, legal, institutional, and financial support.