Joshimath land subsidence (2023)

Topic: Natural Hazards and Disaster Management in India · NCERT: Beyond NCERT

Meaning

Joshimath land subsidence (2023) was the sinking of the ground in Joshimath town, Chamoli district, Uttarakhand, in January 2023. Wide cracks opened in houses, roads and fields, and hundreds of families had to be moved to safer places. It matters because it shows how loose Himalayan ground, poor drainage, unplanned building and big projects such as hydropower tunnels can together make a whole hill town unsafe.

Explanation

What land subsidence is

• Land subsidence: the ground surface sinks, either slowly or suddenly.
• NCERT's Table 6.1 lists it as a terrestrial (land-based) natural hazard.
• How it differs from a landslide
• In a landslide, a mass of rock and soil moves quickly down a slope along a failure plane (a surface of weakness where the upper mass breaks away).

• In subsidence, the ground mainly sinks downwards and cracks open.

• There are four main causes of subsidence:

Cause	Process
Mining	Rock is dug out underground → empty spaces are left → the roof rock caves in
Underground coal fires	Coal seams burn → the burnt-out space collapses
Groundwater pumping	Too much water is pumped out → pore spaces in clay and silt close up → the land sinks
Natural collapse	Limestone dissolves underground, or loose old debris settles

• Joshimath is a case of loose old debris settling, made worse by human activity.

Why Joshimath sank: cause → process → result

• Weak base: old landslide debris
• The town is built on material left by old landslides.

• This material is loose and not packed together (unconsolidated), so it settles easily.

• Water seeping into the ground

• The town had poor drainage and no proper sewer system.
• Waste water and rainwater soaked into the loose debris.

• Water makes the ground heavier and reduces the friction that holds the grains together.

• Extra load on the slope

• Unplanned, heavy building piled weight onto the weak ground.

• Disturbance from big projects

• Tunnelling for the nearby Tapovan-Vishnugad hydropower project and road work disturbed the slope.

• Result: in January 2023, wide cracks opened in houses, roads and fields. A strip of land about 350 metres wide was affected [2].

Conditions that made the town fragile

• Young Himalaya: young fold mountains that are still rising and tectonically active (plate movement still goes on beneath them). This makes slopes unstable.
• Rock and soil: sedimentary and unconsolidated rocks that break easily.
• Weathering: freezing and thawing at high altitude, along with erosion, weakens rock.
• Zone: the young, unstable Himalaya falls in India's very high landslide vulnerability zone. This zone includes areas with heavy road and dam building.

Response and monitoring

• Emergency response
• At a high-level review on 8 January 2023, it was reported that one NDRF team and four SDRF teams had reached the town [2].

• The district administration moved affected families to safer places [2]. In total, hundreds of families were relocated.

• Halt on construction: the State Government stopped all building work in the Joshimath area. This included the Tapovan-Vishnugad power project and the Helang-Marwari bypass road [3].

• Satellite monitoring: ISRO's satellite data showed the ground sinking fast in the weeks around January 2023.

Where it occurs

• Joshimath: in Chamoli district, Uttarakhand.
• It sits above the Alaknanda valley.

• It is a gateway town for Badrinath (a pilgrim centre) and Auli (a ski resort).

• Nearby projects linked to the crisis: the Tapovan-Vishnugad hydropower project and the Helang-Marwari bypass road [3].

• Other subsidence areas in India
• Jharia coalfield (Dhanbad, Jharkhand) and Raniganj coalfield (West Bengal), both in the Damodar valley: subsidence caused by coal mining. Jharia also has underground coal fires that have burned for decades.
• Subsidence caused by mining is also found in Jharkhand, Odisha, Chhattisgarh, Madhya Pradesh, Maharashtra, Andhra Pradesh, Karnataka, Tamil Nadu, Goa and Kerala.
• Fast-growing cities on alluvial plains: subsidence caused by pumping out too much groundwater.

• Karst areas (limestone regions with caves and sinkholes), where limestone dissolves underground.

• Uttarakhand's landslide risk: in the Landslide Atlas of India, Rudraprayag ranks as the most exposed district, followed by Tehri Garhwal. Uttarakhand is among the most affected states.

Don't confuse with

• Landslide: a mass of rock and soil moves quickly down a slope along a failure plane. Subsidence is the ground sinking. Joshimath was a subsidence event on old landslide debris.
• Jharia and Raniganj subsidence: these are caused by coal mining and coal fires on the plateau. Joshimath's subsidence came from loose debris, poor drainage and construction in the Himalaya.
• Malpa landslide (1998): this was in the Kali river valley, Pithoragarh district, and it hit Kailash Mansarovar pilgrims. Joshimath is in Chamoli, above the Alaknanda.
• Wayanad landslides (2024): these were debris flows in Kerala on the Western Ghats, triggered by extreme rain. Joshimath was slow sinking and cracking of a Himalayan town.

Prelims Hooks

• Joshimath is in Chamoli district, not Pithoragarh or Rudraprayag. It lies above the Alaknanda valley and is the gateway to Badrinath and Auli.
• Hydropower project linked to Joshimath: Tapovan-Vishnugad. Road project halted: Helang-Marwari bypass [3].
• About 350 metres wide strip of land affected. One NDRF and four SDRF teams were deployed (review held on 8 January 2023) [2].
• Main natural cause: the town is built on old landslide debris, which is loose material that settles easily.
• NCERT classifies land subsidence as a terrestrial hazard.
• Trap: Rudraprayag is the most exposed district in the Landslide Atlas, but Joshimath is not in Rudraprayag.

Mains Points

• Causes (GS-I / GS-III)
• Natural fragility: young, tectonically active Himalaya, a town on old landslide debris and loose rock.
• Human pressure: no proper sewer or drainage, unplanned heavy building, and hydropower tunnelling and road work nearby.

• Together, these weakened a slope that was already unstable.

• Development versus fragility (GS-III): Joshimath (2023), along with Wayanad (2024), shows how tunnels, roads and unplanned towns weaken unstable slopes.

• Answer frame: carrying-capacity studies for hill towns (how much building and population a town can safely hold); stricter environmental clearances for hydropower and highway projects; ESA-style zoning (Ecologically Sensitive Areas, where big projects are restricted).

• Moving from relief to risk reduction (Sendai Framework)

• Map risky ground using GSI's NLSM at 1:50,000 and NRSC's Landslide Atlas [4][1].
• Watch the ground using satellite monitoring, as ISRO did for Joshimath.
• Plan land use in very high vulnerability zones.
• Build proper drainage and sewers, and resettle people living over unstable ground.

Related concepts

• Landslide
• Landslide vulnerability zones
• Landslides in the Himalayas and Western Ghats
• Landslide mitigation
• Malpa landslide
• Landslide Atlas of India
• Land subsidence
• Wayanad landslides (2024)

Read more

• Landslides and land subsidence