Himalayas are the world’s youngest mountain folds formed by the collision of two landmasses namely, India and Eurasia driven by plate tectonics. These serene mountain ranges stretch over 2,900 km and are home to many exotic organisms, microscopic as well as macroscopic, and have a rich cultural heritage. These ranges separate the Indian subcontinent from the Tibetan plateau. If we look at the geology of the Himalayas, it has varied geological composition and is divided into six zones. The formation of the Himalayas has naturally obstructed several water bodies causing excessive land pressure. Moreover, the region is tectonically active due to the collision of the Eurasian plate. The geological formations make these mountains susceptible to rock fall/ slope failure following an earthquake or heavy rainfall.
Joshimath, a gateway to the Himalayas
Joshimath is an old settlement in the Chamoli district of Uttarakhand and is part of the lesser Himalayas. The town is famous for its rich cultural and religious heritage and is a gateway to several pilgrimage places and Himalayan expeditions. Initially formed as a small settlement it slowly expanded and rose to a town level with an increased population and infrastructural facilities. But this development seems to have been detrimental to nature, proven by several incidences of natural calamities over the last few years. The present incidence of land subsidence at Joshimath seems to be a result of various factors natural as well as anthropogenic.
What is land subsidence?
Land subsidence is the sinking of land due to the withdrawal of water from the rocks leading to underground tectonic activities. The likely causes of land subsidence mining, removal of water, earthquakes, soil erosion, etc. Land subsidence could occur over a large mass of land, a city, or a state or could be localised to a small part. A famous example of land subsidence is seen in Jakarta, Indonesia, with the entire city slowly sinking. Land subsidence incidences have also occurred in the United States in the states of California, Texas, and Florida.
The Geology of Joshimath
Joshimath is located in the Lesser Himalayan zone of the Himalayas and zone IV and V of a seismic zone on the Himalayan fault tines. As to the rock composition, the lesser Himalayas consist of conglomerate, quartzite, phyllite as well as diamictite with interbedded slates. The town is settled on an old landslide site as a result of an earthquake almost a century ago, so it mainly had sand and stone and no solid rock structure. As a result, the land has a limited load-bearing capacity.
Anthropogenic factors leading to land instability
Joshimath town has seen a lot of development in the last few years. An increase in the population has resulted in increased construction of houses, offices, etc. Being a famous tourist destination, the town has seen a lot of infrastructural changes. However, most of these constructions are unplanned so lack a proper drainage system. Deforestation for construction and the improper drainage system has led to a lot of soil erosion in the region making the land even more unstable. Another activity that seems to have contributed to land subsidence is the Tapovan Vishnugad hydroelectric project on the Dhauliganga river near Joshimath, Uttarakhand. A big tunnel was dug up near Joshimath as part of the project. Moreover, the project takes uses a lot of water from the area leading to the drying of land at Joshimath. Experts suspect that these factors could have acted as a trigger for the increased tectonic activities. To make the situation worse, there is an ongoing construction of the Char Dham project, a 900 km all-weather road to the religious shrines of Char Dham. All of these new and unplanned constructions in the hilly regions have led to the obstruction of water bodies increasing the pressure on the land. These anthropogenic activities combined with the geological makeup of the region seem to have caused land subsidence.
The prior warnings in 1976
The government-appointed Mishra committee in 1976 had clearly warned about the unstable land situation at Joshimath then. The report had strictly advised against any new construction work, blasting, digging, removal of boulders, and felling of trees. The committee had also recommended a massive campaign for tree plantation and the construction of a proper drainage system to curb soil erosion.
A full stop to all developmental projects in the Himalayas?
The incident has been a real eye-opener for us. It has made us question our ways and means of development making it clear that the only way to move ahead is with the correct tools aiming for sustainable development. What we have to understand here is, the Himalayas form a very sensitive ecosystem because of its geological features. As a result, any developmental project that we plan needs thorough consideration of the region’s geological makeup. All of the construction work has to be planned and balanced by afforestation. Not only this, the local government and NGOs should promote sustainable agricultural practices for water and soil conservation. It is only with these safe and sustainable practices that we can conserve the beauty of the magnificent Himalayas and protect the local communities.