ISRO report missing from NRSC website
• The ISRO report released yesterday states that in just 12 days between December 27 and January 8, the land in Joshimath sank by 5.4 cm.
A report on the Joshimath landslide by the Indian Space Research Organization (ISRO) has gone missing from the NRSC-govt-run website.
The report released yesterday states that in just 12 days between December 27 and January 8, the ground in Joshimath has sunk 5.4 cm.
Furthermore, the report claimed that the land subsidence was slow between April and November 2022, during which Joshimath sank by 8.9 cm.
These pictures were taken from the Cartosat-2S satellite.
“The area subsided by about 5 cm in a span of a few days and the areal extent of subsidence has also increased. But it is confined to the central part of Joshimath city," said the national report Sensing.
It stated that a subduction zone resembling a typical landslide shape had been identified – tapering at the top and fanning at the base.
The report said that the Taj of Dhansav was located at an altitude of 2,180 meters near the Joshimath-Auli road.
The images show the army helipad and the Narasimha temple as prominent landmarks in the subsidence zone spread over the central part of Joshimath town.
After the report became public, fear prevailed among the local people. The District Disaster Management Authority said that 25 more families were evacuated yesterday, taking the total number of such families to 185.
Meanwhile, Hindustan Times has reported that the central government has refuted the theory that the submerging land in Joshimath is related to NTPC's hydroelectric project.
Environmentalists, geologists as well as local people have said that a tunnel connected to the National Thermal Power Corporation's (NTPC) 520 MW Tapovan Vishnugad hydroelectric project near Joshimath town caused an aquifer to burst, causing land subsidence in the holy town.
However, the Center in its draft report has said that the possible causes of land subsidence in Joshimath town and surrounding area include excessive dump material, subsurface saturation as a result of poor sewerage, inadequate surface runoff disposal, rain water and domestic waste water. Natural drainage due to flood events, erosion on the left bank of the Alaknanda River, occasional heavy rainfall, periodic seismic activities, and increase in construction activities.
Yesterday an NTPC official had also given a similar statement.
State-owned NTPC told the power ministry that the 12-km-long tunnel linked to the Tapovan Vishnugarh hydroelectric project is one kilometer away from Joshimath town and is at least one kilometer below ground.
Stating that land subsidence in Joshimath is a very old issue, which was first observed in 1976, NTPC quoted the MC Mishra committee appointed by the state government of that year to say, "Cleaning of the hill, natural restoration of the rest Cultivated field for "swelling/cracks" due to angle, seepage and soil erosion.
The construction work of the 4x130 MW Tapovan Vishnugad project started in November 2006. The project involves construction of a concrete barrage at Tapovan (15 km upstream of Joshimath town).
The project was supposed to be completed in March 2013 but almost 10 years later it is still 'under construction'. The cost of the project has increased from an initial sanctioned investment of ₹2,978.5 crore to an estimated ₹7,103 crore.
NTPC said, "The tunneling in this section has been done by means of Tunnel Boring Machine (TBM) without disturbing the surrounding rock mass."
The company said that during the construction of the tunnel, local people had raised concerns about drying up of the water table in the future in Sailong area, about six km from Joshimath town.
NTPC also told the power ministry that there is no active construction going on in the area for almost two years.
The state government has started demolition of unsafe buildings in the town and some residents have been shifted to safer places.
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