Recently, eight premier institutions in India, including the Indian Space Research Organisation (ISRO), conducted separate studies to understand the reasons behind land subsidence in the Himalayan town of Joshimath, located in Uttarakhand.
Central Building Research Institute (CBRI) Report
The CBRI report stated that 44%, 42%, and 14% of Joshimath’s structures are composed of masonry, RCC, and other construction typologies respectively. Alarmingly, 99% of these structures are non-engineered and do not comply with the National Building Code of India, 2016. The town stands on Vaikrita groups of rocks overlain by morainic deposits, making the area less cohesive and at risk of gradual subsidence and landslides.
National Institute of Hydrology (NIH) Findings
After mapping various springs, drainage networks, and areas of subsidence in the region, the NIH suggested a correlation between land subsidence and subsurface water in Joshimath. The institution pinpointed the safe disposal of upper-reach water and waste as a top priority for the town.
Wadia Institute of Himalayan Geology (WIHG) Study
The WIHG indicated that earthquakes could be causing slow and gradual land subsidence. They also mentioned internal erosion caused by subsurface drainage due to rainwater infiltration, ice melting, and wastewater discharge from households and hotels as contributing factors.
ISRO’s Perspective
According to ISRO, toe-cutting phenomenon and slope instability caused by seepage of local drainage water in the soil might be causing subsidence in the Joshimath region. Furthermore, terrain and edaphic characteristics, loose and unconsolidated moraine materials, and flash flood events in recent past also contribute to the issue.
About Joshimath
Joshimath serves as a tourist town and an important stopover for visitors traveling to Badrinath, Auli, Valley of Flowers, and Hemkund Sahib. Besides its tourism value, it is also of strategic importance to the Indian armed forces. Home to one of the four cardinal Maths established by Adi Shankara, Joshimath faces the risk of landslides and other natural disasters due to its high-risk seismic Zone-V location.
Strategies to Save Joshimath
A recommendation for halting development and hydroelectric projects in the region has been made by experts. Moreover, immediate relocation of residents to safer places, reimagining town planning, revamped drainage systems, and replantation at vulnerable sites are needed steps. Government and civil bodies, with assistance from military organizations like the Border Roads Organisation (BRO), need to work together in a coordinated manner to mitigate the crisis.
Understanding Landslides
A landslide refers to the movement of rock, debris, or earth down a slope under gravity’s influence, constituting a type of mass wasting. Landslides can occur through different modes including falls, topples, slides, spreads, and flows.
Previous UPSC Civil Services Examination Questions on Landslides
In previous years, questions around the causes and effects of landslides were asked on the UPSC Civil Services Examination. They included discussions on why landslides are more frequent in the Himalayas than in Western Ghats and the components of the National Landslide Risk Management Strategy.
