Interview with Dr. C.P. Rajendran, Adjunct Professor National Institute of Advanced Studies Bengaluru

In view of the recent subsidence in Uttarakhand's Joshimath area and also in Nainital etc.... concern of the locals is growing that they might be swallowed up by the subsidence. Digital Discourse Foundation's Malini Shankar conducted an expert interview with a geoscientist - Dr. C.P. Rajendran, Adjunct Professor, National Institute of Advanced Studies Bangalore. 

Construction in the Himalayan region in the name of development is not just eco detrimental but suicidal. Photo Credit: Malini Shankar

1.     Dr. Rajendran, You have been an outspoken critic of the Char Dham project. But the government is going ahead with construction activity at a relentless pace. In the next ten years, they are planning to build 66 tunnels in the small hill state of Uttarakhand.  We already have 18 tunnels in operation. Your comments?

A: “I have always thought the Char Dham road project is a “freeway to disaster”. As feared, it is indeed turning out to be an unscientific road-construction project with catastrophic consequences to the mountain ecology. There are important environmental caveats to be respected before engaging in a mammoth engineering project in the Himalaya. The authorities in their enthusiasm to have a ‘smoother” and “faster” “all-weather” connectivity to facilitate pilgrim tourists from the plains and Armed Forces ignored the government’s own recommended “best practice norms” to minimize the impact on the mountain ecosystems and landscapes and that these engineering interventions are done with scant regard to the local geology and environment. The construction of highways and railway tracks has now become a prime cause for landslides and its occurrences have doubled over the years”.

Construction of huge dams is not only unsustainable, but has repercussions on the ground water table and seismic consequences. A picture of bhakra Nangal Dam here hardly looks like it was Asia's biggest dam at some point! Photo Credit:  Apar Singh Bataan CC BY SA 3.0

Carving tunnels by carving the rocks in asking for a Himalayan disaster.  Photo credit: Malini Shankar. 

Such is the fragility of the geological subsidence in the Himalayas that by the time I drove back from Rohtang to Manali the rock fall almost blocked my return! Photo credit: Malini Shankar. 

Tunneling through the Himalayan ecology calls for drilling through the rocks. It can change the very hydrology of the Himalayas. Nming the tunnels after political figures is no more than an exercise in political one upmanship - to the detriment of locals. The subterranean water sources and the water table itself shifts because of drilling and tunneling. It is a recipe for disaster... a Himalayan one. Photo credit: Malini Shankar. 

2.      While some of these are road tunnels, many are being built as part of the rail project that is going to crisscross the Himalayas? Already 50 per cent of the work on the Rishikesh- Karnprayag rail project has been completed. The tunnel accounts for 70 per cent of this project with a 14 km long tunnel from Devprayag to Janasu under construction. What kind of environmental destruction will this involve?

A. Out of the 125 km long track, the train will travel 105 km through tunnels; the longest tunnel being the 14-km long tunnel from Devprayag to Janasu. Unlike many mountain chains in the world the Himalaya is the youngest and most active in terms of tectonics. There is a belief that building tunnels may decrease the infrastructural impact on the environment. In fact, these subsurface structures could result in gross damage to the environment including the concentrations of pollutants from traffic exhaust compounded by a microenvironment with no sunlight and limited dispersion in such long-distance tunnels. The rail traffic may rely on electric locomotion, but constantly generated vibration during the train movements is another issue related to the tunnels that will keep the mountain slope eternally unstable and thus make it vulnerable to slide at the slightest trigger. Blasting for tunnels would often lead to weakening the rock formations leading to landslides, besides huge quantities of excavated rock waste. Irreversible impact on the groundwater like descending water levels also has been observed in the areas of tunnel construction. Dozens of global and Indian examples show that tunneling would also affect the surface and subsurface hydrology of the region.

 3. If this was not bad enough, the world’s longest 30 km long road tunnel is being constructed between Dehra Dun and Tehri despite scientists warning about the increase in landslides that such large-scale construction work will involve…?

A. Landslides do not occur in isolation. Depending on the nature of rocks and their inherent nature, and the blasting methods employed for road and dam constructions act as contributing triggers / triggering mechanism. The geology of the rocks and the nature of fissility within the rocks (meaning the tendency of the rocks to split along the planes of weakness) are important criteria to be considered. Many times, the slip occurs along such fractures. The increased anthropogenic activities like road construction have made the hill slopes extremely unstable. That is why the recurring landslides gone up in numbers in the Himalaya contributed also by heavy downpour and cloud bursting due to climatic changes. The excavation of a tunnel induces stress changes and consequent deformation within the rock formations could also contribute to landslide vulnerability.

 4. Villages situated around where the mountain slopes are sinking and with massive excavation work being done for tunnel construction, villagers have found their homes have developed cracks. The list of complainants is increasing. Is this because of geological subsidence or anthropogenic destruction of the hydrology? What does this indicate?

A. The residents constantly complain about damage to their house and drying up of their water sources. Such massive level of construction procedures will impact the villagers and livelihood of people who are living there. The blasting done during the construction has resulted in the cracks on their houses and other buildings. Equally alarming is the vanishing spring water and community water sources.  For instance, a report by the Peoples’ Science Institute states, “Their natural water sources, gharats, irrigation canals have all dried up, so much so that the village does not even have enough water to immerse mortal remains of the departed Souls. Adding to their woes, cracks have started appearing on the walls of homes and other buildings”. Villagers believe that the blasting done during the construction of four underground tunnels has led to the drying up of their water sources and cracks in their houses. Erratic rainfall and ecological degradation associated with land use change for infrastructural development are already impacting mountain aquifer systems. A report of  Aug 2018 published by NITI Aayog titled ‘Inventory and revival of springs in the Himalayas for water security’ states, “There is increasing evidence that springs are drying up or their discharge is reducing throughout the Indian Himalayan Ranges (IHR), and indeed, throughout the entire Hindu Kush Himalayan (HKH) region”. Groundwater use in the Himalayan states differs from that in the plains, as large and contiguous aquifers do not exist in the hills. Villagers tap into small pockets, called perched aquifers where water that percolates into the soil (depending on the orientation of the rocks. Sometimes these small aquifers, overflow emerges as a spring. The evidence suggests that those springs are drying up or their discharge is reducing in the IHR and the adjacent regions. 

Tunneling may cause impediment to the groundwater if it is perpendicular to the tunnel axis. It can have an adverse effect on the structures as well as can influence the local ecosystem by hampering the vegetation. Many issues concerning the mountain population confront the social conscience – despite claims of a successful tourism policy. Most of the local population continues to live in abject poverty and the innumerable dams across the Himalayan rivers provide no relief to the local people (read women) who must trudge miles for water from natural springs that are also now drying up fast.

Q. Equally alarming is the fact that the strategically important town of Joshimath is sinking with many of its houses having developed cracks. Its residents recently met the Uttarakhand state disaster management secretary and told him they believed the tunnel of the Tapovan Vishnugad hydro electric project and a bypass built as part of the rail project are responsible for this present situation. Your comments.

A. The residents allege that cracks had been developing in their houses since last year and after failing to get a proper response from the district administration The geoscientists who have visited Joshimath have recorded that several areas in that town of Chamoli district located at an altitude of 6150 feet are sinking rapidly due to human-induced causes. An expert team constituted by the Uttarakhand Disaster Management Authority (USDMA) has certified in their 2022 report that “Joshimath town located on thick cover of landslide material has been witnessing gradual sinking for a long time… Further uphill from the Joshimath -Auli Road cavities and ground fissures were found.

 Tapovan Vishnugad hydro project tunnel passes just below Joshimath could be a contributing factor among other factors. During the construction of the tunnel it is reported that the boring machine had perforated a water-bearing stratum on the left bank of the Alaknanda River near the Shelong Village. The site of this accident is about 1 km below the surface, below Auli Village. A report published in Current Science by Piyush Rautela and Bisht back in 2010 informs that that this large-scale discharge of 60-70 million litres per day and the report forecast drying up of the springs in the region and the consequent ground subsidence in future.

Ravi Chopra, former chair of the High-Power Committee (HPC) on the all-weather Char Dham Road project, said: “The city sits on old rubble which is generally prone to slow slippage.” Chopra further said that among various reasons for the subsidence of Joshimath, the top two reasons would be tunneling and slope cutting. He said: “The precautions advocated by the Mishra committee since 1976 have not been respected. In addition to the rapid growth of the city, we have imposed additional burdens by digging a tunnel that has perforated a large aquifer.”

“The rubble base on which the town was built could also be a part of old glacial deposit. The sedimentary characteristics determine the amounts of infiltration and ground water flow. Therefore, it is likely that hydrological properties may not be inherently conducive for water containment. The sinking of the town is the direct consequence of depletion of groundwater level caused by the anthropogenic activities. Groundwater drawdown can be dangerous for the nearby structures as the decrease in water (table) force affects the soil layers and can cause sinking of the land level. Management Authority (NDMA) report on the Chamoli disaster (the 13.2 MW Rishiganga Hydropower Project and the 520 MW NTPC Hydropower) clearly states: “in the long term, it will be necessary to focus on finding alternative sources of energy, as the area appears to be environmentally sensitive.”

Q. All the solutions being provided are cosmetic, it appears. The Chamoli district magistrate had in June 2022 ordered the construction of a one-and-a-half-kilometer wall construction to be built along the Alaknanda river to stop soil erosion. Will this help?

A. While implementing a free-way project in the Himalaya, a major question that stares you down is whether the mountain morphology with steep slopes and sharp gradients is easily amenable to human engineering.  The steep gradients of the Uttarakhand Himalaya make it dynamically heterogeneous, in terms of climatic variables, hydrological processes and biodiversity, at every turn of the mountain path. This has become amply clear from the recent series of disasters in this part, the impact of which was exacerbated by the unsustainable human interferences in the natural systems. All these “hard approaches” like building retaining wall will not work in the long-term in such a dynamic environment. Such walls will eventually be degraded due to upslope erosion, sliding, slumping etc. or river scouring during the flood seasons (sic). Stabilization of the bank must be done primarily by planting the appropriate species of trees. The rivers need its space to flow and we need to respect their relationship with their floodplains.

 

Q. The Himalayas are a young mountain chain prone to earthquakes. Already with 100 dams under construction in Uttarakhand, scientists warn that this heavy construction work will disturb the isostatic equilibrium in these mountains thereby increasing the possibility of earthquakes.

A. It is reported from many sites that the gravitational load created by the large reservoir disturbs the state of isostatic equilibrium of the Earth’s crust.  … this generally means seismic pressure generated by static water bodies like dams and reservoirs (Emphasis mine). The Earth's crust converts the potential accumulated energy of hydrostatic pressure into the kinetic energy of vertical displacement that lasts for many decades; these are generally called reservoir generated earthquakes. The case studies indicate that induced earthquakes  in the tectonically active Himalayan terrain, characterized by widely varying geology with folds, faults, thrusts and shear zones, such geological uncertainties cannot be ruled out. The hydrostatic pressure variations arguably have been found to change the in situ strain in many areas of the Himalaya. How important this variable is in the generation of earthquakes is yet to be proven. The entire central Himalaya is currently locked and the accumulated stresses due to Indian plate collision is waiting to be released in earthquakes. 

 Q. But apart from Joshimath, Bhatwari and Uttarkashi are also sinking. What does this indicate?

A. What we see in Joshimath and towns like Uttarkashi is a warning of what’s stored for us in future. Experts believe that the resilience of the Himalayan ecosystem is likely to overshoot thanks to an unprecedented combination of climate change and its consequences. flooding, drought, wildfire, etc, along with other global change drivers (e.g. imbalanced land use, pollution, fragmentation of natural systems and over-exploitation of resources). The melting of Himalayan glaciers is also likely to impact local rivers, either in the form of massive seasonal flooding or forcing them to dry up. We must remember that the Himalayan environment is on the brink of collapse. It may not be able to withstand another push generated by intrusive anthropogenic activities in the form of massive construction projects of highways, railway tracks and dams. When large tracts of forests are being diverted for hydropower and road projects there are no serious attempts for compensatory afforestation.

Q. Why does the government not pay attention to scientific objections and conduct technically sound environmental impact assessments using independent experts?

A. I fail to understand why the concerns expressed by many experts have been ignored. The economic interests play a major role. This is clear from the fact that there is a mad rush for awarding hydroelectric projects to private companies. Why? Commercial lobbies, I daresay.

Infrastructural development is one thing, but we also need to understand the fragility of the landscape that we are interfering with. A realistic developmental strategy should be based on a blueprint that strikes a balance between infra-structural development and acceptable levels of risk and the carrying capacity of the terrain. The daily average footfall last year in these areas was around 58,000. Ground reports also say that plastic waste dumped in large or small pits and the cleaning operations resort to open burning are highly hazardous. The Char Dham routes are also witnessing this growing mound of garbage since the beginning of the pilgrimage season. Unregulated human activities during the pilgrimage are most likely to impact the quality of water and air in these regions. Imagine the millions of travelers who would be visiting the hills as part of Char Dham pilgrimage circuit using the upcoming rail and road travelling facilities and how this is going to pollute the mountain environment. Many of the hydroelectric projects need to be reviewed from the perspective of its long-term adverse impact. The 2013 Kedarnath flood was a wake-up call. The intensity of this disaster was directly proportional to the unregulated rise in tourism that led to a construction boom in unsafe zones such as the river valleys and floodplains and slopes vulnerable to landslides, violating laws on land use. Any human-induced change beyond the Himalayas’ carrying capacity will have an impact on stream run-offs and erosional or depositional processes. Considering such vulnerabilities, we need to keep the scale of human-induced disturbances to the minimum level possible. The Char Dham project in its current form goes against all environmental safeguards.

Q.   These projects are costing this hill state lakhs of crores of rupees. Could these funds not have been better utilized?

A. Many scholars like Sunita Narain have suggested how we should go about funding a development strategy for the Himalayas that should come not at the cost of the environment. This strategy should be based on the region's natural resources like forest, water, biodiversity and ecotourism. Rather than building massive dams, focus should be on small projects that would be helpful in providing local energy supply. Agriculture in the Himalayan mountains is closely linked to animal husbandry and natural forests. Most of the farmers have now abandoned their traditional practices and local varieties of seeds and wait for the state or private sector to supply necessary inputs. It is reported that due to massive migration of villagers to the Indian Plains, only less than 20% of the agricultural land in the Himalayan districts of the Uttarakhand is being farmed and the rest 80% has become fallow land. This is one area that needs a massive influx of funding.  There should be initiatives to form organizations of neighborhood groups of women as an effective strategy for the empowerment of women in the Himalayan villages, who would be in position to take care of the local environment, water sources, sewage and garbage management and sustainable tourism. The climate change has also now forced upper valley farmers to new farming options and expert guidance should be provided to them for better options. An appropriate developmental strategy should also be able to use the traditional knowledge, agricultural practices, construction practices and local cultural aspects.

Q.   Is it possible to scientifically measure subsidence and will that serve as an early warning as it seems to be the case in Uttarakhand now?

A.    Yes, it is possible to measure subsidence as it was done by the ISRO. The January 11, 2023 report by isro said that the ground surface in Joshimath recorded a subsidence of around 9 cm between April and November 2022 before rapidly dropping roughly 5 cm in merely 12 days in December-January. If the subsidence had been under satellite surveillance, that would have helped in early warning.

 

Q. What will be the impact of anthropogenic conflict / footprint on the hydrology / subterranean water table in Joshimath?

A. There are currently many speculations about what could have happened. Experts are being deputed to undertake detailed studies to understand the events that led to the disaster. But a different kind of mechanism appears to be at play here. Some experts from the Government-run institutes have stated that poor drainage due to population pressure have impacted the surface runoff disposal and the consequent pressure exerted by the percolating water, as what would be expected in a landslide scenario, can cause fissuring and sinking. And they say that the town of Joshimath is sitting on a landslide material. But  my understanding of the problem runs counter to this official interpretation. Across the world, groundwater depletion is what is recognized as a cause for subsidence. In Joshimath, the tunnelling and other engineering projects could have damaged the water-bearing aquifers, leading to leakage of massive amounts of water from the inter-bedded clays and silts within the glacially-deposited sediments on which the town is built. Such massive removal of underground water reduces the pore pressure (pressure of water in the pore space of rocks), causing sediment shrinkage and land subsidence. 

 

Interviewed by Malini Shankar, Digital Discourse Foundation