Prof Vibhuti Rai, Department of Geology, University of Lucknow
Namrata Singh, Department of Chemistry, University of Lucknow
The Himalayas, considered as the third pole region of the world, are one of the most fragile areas of the earth on account of several natural processes such as earth’s tectonics, on slot of high altitude of weather and as a geomorphological wall that separates Indian subcontinent with the Tibetan Plateau. The mighty snow-covered peaks generate a range that is called as Higher Himalayas, geologically called as the Central Crystalline Zone.
The Himalayas are fragile because they are one of the regions where maximum earthquakes occur in the entire subcontinent along with several processes of mass wasting which has chiselled this mighty mountain system to generate a huge pile of broken sediments that are carried over by a network of rivers from across the Himalayas to the vastness of the Ganga plain. The huge load on the environment and sustainability aspect has been badly affected due to excessive growth in these townships and other developmental activities and it has been observed that many of these places have started getting de-stabilised as a reaction to unprecedented growth and development.
In recent weeks, Joshimath, the gateway to Dev-bhumi Badrinath, also being the first jyotirmath installed by Adi Shankaracharya centuries ago, is in the news as the entire township is inching towards disaster by way of collapsing and rupture of land and concrete structures alongside a huge outflow of muddy waters by the newly generated ground soil seepages, suggesting that the entire city might collapse by sliding down the northern slopes of the Auli Hills. A recent observation has suggested that the script of the disaster was written about five decades ago when this region was put on the developmental map by the state government in order to provide thrust to the economy of Joshimath, which used to be a small township under the district Chamoli. These developmental plans were commissioned without estimating the damage that would incur due to unthoughtful planning, non-scientific approach and without considering the various geological and hydro-geological parameters. The careless growth in road infrastructure, civic infrastructure, development of the cantonment etc. on a very fragile landscape is culminating into the giant disaster, to which we are all going to be a witness.
The following domains are responsible for the Joshimath tragedy which should be set as an example of failed development of urban planning and can help other parts of the Himalayan region to avoid such a catastrophe:
1. Geomorphological- slope sustainability
2. Subsurface soil and rock conditions
3. Improper drainage
4. Sewage disposal – the chaos of soak pits
5. Road widening project
6. Excessive vehicular load
7. NTPC hydro-electric power related development
8. Religious tourism and related infrastructure
9. Unplanned development for civic amenities
Joshimath occurs in a geologically active terrain of Central Crystalline which is sandwiched between two active tectonic plains of Main Central Thrust (MCT) in the south and Martoli Fault (MF) in the north, which are regional tectonic ruptures running all across the Himalaya. The Himalayan tectonics, which is always associated with earthquakes, has made the region highly deformed and fragile. Helang is a very place close to Joshimath town in the south of it, from where the MCT passes. Four major developmental projects were in operation in an around Joshimath, namely, the Auli Skiing range, four-lane highway, NTPC hydroelectric project and development of huge tourist-related amenities and facilities which can be mainly responsible for the present scenario as small township of just 10,000 inhabitants in 2011, for which resources were available was turned into a small city of over 50,000 people in 2022 with the same proportion of numbers in the development of dwelling units. The impact of over 12 lac pilgrims visiting Joshimath every year has turned the city into chaos as the region occurs on a steep slope with the underground strata of rubble, scree, glacial till, and mud covering the slopes for the foundation of the concrete structures. Although, the Central Crystallines are made up of metamorphic rocks which are relatively quite strong but their foliation and cleavages reduce their strength specially if they are on a sloping side of a hill. The ground water penetration is not much in these rocks but the overlying cover of the muddy rubble provides the host for soke pits and ground water which could be retained for some time.
Cause of the disaster
A recent survey of the area by one of us (Namrata Singh) has suggested that the city has developed huge amount of water seepages from the ground and sub-surface in the form of muddy springs through which fine clay and mud water oozing out for almost three months, which might have been related to liquefaction. Liquefaction occurs when a cohesionless saturated or partially saturated soil substantially loses strength and stiffness in response to an applied stress such as shaking during an earthquake or other sudden change in stress condition in which material that is ordinarily a solid behaves like liquid. Sometimes the soil which becomes very wet underground get super saturated with water which becomes unbearable and the water-logged sediment give up its cohesion and raw pieces of rubble, soil, mud, and water starts flowing, thereby generating cavities in the region. These cavities become hollow for the overlying structure thereby making the concrete structure rupture and genesis of crevasses and outflow of mud and water and in due course, the overlying buildings stopple and there is general chaos. In our view this is the main reason for the present crisis of Joshimath which cannot be saved now as it is a human created tragedy and the fight is against the mighty nature.
In a nutshell, we can say that the sliding town on a sloppy surface is a huge human tragedy as we have undermined the nature’s strategy to punish miniscule mankind who thinks that he is mightier than the mightiest. Let us realise now that the nature is supreme and it can always make corrective measures where man fails.
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