The ‘Himalayan’ Crisis | Current Affairs & Hindu Analysis: Daily, Weekly & Monthly - UPSC PDF Download

Introduction

• Over the past few weeks, cracks have developed in several roads and over 600 houses in Joshimath, Uttarakhand, which is the gateway town to the Badrinath temple. This has caused panic and protests among the local population. On Sunday, a high-level meeting was held by officials from the Centre, state government, and agencies such as NDMA, GIS, and NIH to assess the situation. However, the Supreme Court has declined an urgent hearing on a plea related to the incident. 
• An expert panel, appointed by the Centre to evaluate the sinking of the ground surface in Joshimath, has recommended the demolition of two hotels, and the authorities have begun the process. The affected families are being provided shelter by the state government. According to experts, Joshimath city has been constructed on an ancient landslide material, which means it is built on a deposit of sand and stone, not rock, and therefore does not have a high load-bearing capacity. This makes the area extremely susceptible to ever-increasing infrastructure and population.

Land Subsidence

• Land subsidence occurs when certain types of rocks, like fine-grained sediments, experience significant groundwater withdrawal, leading to a lowering of the land-surface elevation. This can cause damage to buildings, aqueducts, well casings, bridges, and highways, and can worsen flooding problems.
• Subsidence is commonly caused by activities such as pumping water, oil, or gas, as well as the dissolution of limestone aquifers (which can create sinkholes), drainage of organic soils, and initial wetting of dry soils. Changes in land gradient can also have negative impacts on sewer lines and storm drainage.
• Climate can also affect the groundwater system, with wetter periods resulting in water storage and drier periods leading to water removal from storage. Overdraft or excessive pumping of a groundwater aquifer over a long period of time can also result in subsidence and sinking ground surface, causing millions of dollars in damage.

Causes of it

• Joshimath is situated in Zone V of the Seismic Zonation Map and has experienced earthquakes of magnitude less than 5 on the Richter scale. The gradual or sudden settling of the earth's surface due to the removal or displacement of subsurface materials has resulted in structural damage in almost all parts of the city.
• The 1976 Mishra Committee report states that Joshimath is located on a deposit of sand and stone, not on the main rock, and it is built on an ancient landslide. The report further suggests that landslides are also triggered by the undercutting of river currents in Alaknanda and Dhauliganga.
• The area has scattered rocks covered with old landslide debris, including boulders, gneissic rocks, and loose soil, with a low bearing capacity. As the area falls under a seismic zone, it is vulnerable to frequent earthquakes.
• The gneissic rocks are highly weathered and have a low cohesive value with a tendency of high pore pressure when saturated with water, particularly during the monsoon season. Increased construction, overpopulation, hydroelectric projects, obstruction of natural water flow, and the widening of the NH have rendered the slopes highly unstable in recent decades.

Impacts of it

• Several roads and houses have developed cracks, leading to the evacuation of 68 families to temporary relief centers, with around 90 more to be evacuated soon, as per officials.
• The incident could potentially impact the Char Dham project and tourism, which is a significant source of revenue for Uttarakhand.
• The livelihoods of families involved in tourism and related activities may also be affected.

Way forward

• Experts have advised that the development and hydroelectric projects in the area should be halted completely. However, the first priority is to relocate the residents to a safer place and then redesign the town's planning to incorporate the new variables and changing geographical conditions.
• One of the biggest factors that needs to be studied and redeveloped is the drainage planning. Currently, the city is struggling with poor drainage and sewer management, which is causing waste to seep into the soil, weakening it from within.
• The state government has asked the irrigation department to address the issue and devise a new drainage system plan. The committee has recommended imposing restrictions on heavy construction work, such as blasting, digging to remove boulders for road repairs, and felling of trees.
• Experts have also suggested replanting in the area, especially in the vulnerable locations, to maintain the soil's capacity. Although the state already has weather forecasting technology to warn locals of impending events, its coverage needs to be expanded.