Joshimath Sinking: Landslide incidents have become a problem in Joshimath, Uttarakhand. Joshimath is at an altitude of 1890 meters in the ‘Garhwal Himalayas’ of Uttarakhand under the Himalayan region. it is a small town. The population here is more than 20,000. The city is built on a fragile hill slope, which is reportedly in crisis due to unplanned and indiscriminate development projects. There has been a rapid increase in both construction and population here in recent years. Recently, the process of land subsidence started here and now the situation is frightening. More than 500 houses in the area have developed cracks, the ground is bursting and roads are sinking.
The Uttarakhand government on Thursday banned construction works in Joshimath and its surrounding areas due to land subsidence. The construction work reportedly caused cracks in 561 houses in the area, leading to protests by panicked locals. Local people allege that this problem has arisen because of NTPC’s hydro power project. Hotels and offices in Joshimath have all collapsed. Here people have only two options – either leave their homes or stay in the area risking their lives. Let us know why this area of Uttarakhand is sinking? What does science say?
1. Location, Topography and Weather
Joshimath is situated in the middle slope of a hill surrounded by the Karmnasha and Dhaknala streams in the west and east and the Dhauliganga and Alaknanda rivers in the south and north. According to a study by the Uttarakhand State Disaster Management Authority (USDMA), the city is in a landslide-prone zone and the first occurrence of subsidence was recorded in the Mishra Commission report in 1976. The area around Joshimath town is covered with a thick layer of overburden material. “This makes the city highly vulnerable to submergence,” said Piyush Rautela, executive director of the USDMA.
“The flood events of June 2013 and February 2021 have had an adverse impact on the landslide area, with increased erosion and sliding along the Ravigram Nala and Nau Ganga Nala after the Rishi Ganga flood from February 7, 2021,” the study said. It is a reference to the bursting of a glacial lake that caused a flood that resulted in the loss of 204 lives, mostly migrants working on a hydro power project.
It was told in the study that on October 17, 2021, the landslide area had further weakened when Joshimath recorded 190 mm of rain in 24 hours. The massive amount of water carrying debris from Dhauliganga during the last flood event (February 2021) has also increased erosion along the left bank of Alaknanda, below its confluence with Dhauliganga river at Vishnuprayag. It has been said in the USDMA report that the stability of the slope on which Joshimath city is situated was adversely affected.
2. Unplanned construction
The local people of Joshimath believe that this problem has arisen because of NTPC’s hydro power project. Hemant Dhyani, a member of the Supreme Court-appointed High Powered Committee (HPC) on environment and Char Dham project, said that despite being fully aware of the geological vulnerability of the area, hydro power projects have been approved around Joshimath and Tapovan, in which Vishnugarh HE project is also included. He pointed out that a decade ago, experts warned that sudden and large-scale surface water withdrawals could trigger subsidence in the region, but no corrective measures were taken, so this is not surprising That city is sinking. Explain that under this scheme, long tunnels are being made by cutting the mountains. Since the power project started 2 years ago, the process of cracks on the ground had started here. Due to government projects, blasting is being done to make tunnels all over the city, which is a danger bell.
3. Improper Water Drainage
Experts and the USDMA pointed to an increase in surface water seepage as a possible reason for the subsidence. First, anthropogenic activities on the surface have blocked natural drainage systems, forcing the water to find new drainage routes. Second, there is no sewage and wastewater disposal system in Joshimath city. Hemant Dhyani said that sewage overburden reduces the shear strength of the soil. This is visible around Sunil village of Joshimath, where the effect of water pipes sinking is visible.
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