Hill or city, urban planning cannot be an afterthought

General Studies Paper 1

• Context: On December 24, 2009, a tunnel boring machine in Joshimath, Uttarakhand,hit an aquifer about 3kms from Selang village. Resulted in the loss of nearly 800 liters of water per

Land subsidence:

• It is the sinking of the ground because of underground material movement.
• Subsidence can be caused by gradual settling or sudden sinking of the Earth’s surface (National Oceanic and Atmospheric Administration (NOAA, USA)).
• The causes for subsidence generally are:
  • Natural causes– earthquakes, glacial isostatic adjustment, soil compaction, erosion, sinkhole formation, etc.
  • Resource extraction– extracting resources such as oil, water, minerals, natural gas, etc. from the ground by mining, fracking or pumping.
  • Construction of infrastructure– excess infrastructure load above the carrying capacity of the soil.

Joshimath or Jyotirmath:

• It is a temple town and a municipality in Uttarakhand’s Chamoli district.
• The math or monasteryis one of the four cardinal institutions founded by Adi Shankaracharya in the four corners of India.
• The cantonment at Joshimath is one of the closest to the China border.
• Joshimath has no systemto manage wastewater.
• Ongoing infrastructure projects(the Tapovan Vishnugad dam and the Helang-Marwari bypass road) may also worsen the situation.

The problem in hilly urban India:

• An estimated 12.6% of India’s land areais prone to landslides, especially in Sikkim, West Bengal and Uttarakhand.
• According to the National Institute of Disaster Management (and highlighted in the National Landslide Risk Management Strategy, September 2019): Urban policy is making landslides worse .
• Land use planning in India’s Himalayan towns and the Western Ghats is often ill-conceived, adding to slope instability.
• Tunneling constructionis weakening rock formations.

What steps need to be taken?

• Acquiring credible datais the first step toward enhancing urban resilience with regard to land subsidence.
• The overall landslide risk needs to be mapped at the granular level.
• The Geological Survey of India has conducted a national mapping exercise (1:50,000 scale, with each centimeter denoting approximately 5(zero point five)km).
  • Urban policymakers need to take this further, with additional detail and localisation (1:1,000 scale).
• Areas with high landslide risk should not be allowed to expand large infrastructure
  • there must be a push to reduce human interventions and adhere to carrying capacity.
• Any site development in hazardous zones needs assessment by a geologist (with respect to soil suitability and slope stability) and an evaluation of its potential impact on buildings that are nearby.
• Corrective measures (retention walls), with steps to prohibit construction in hazardous areas.

Case of Aizawl, Mizoram:

• It is in ‘Seismic Zone V’, and built on very steep slope
• An earthquake with a magnitude greater than 7 on the Richter scale would easily trigger over 1,000 landslides and cause large-scale damage to buildings.
• The city has developed a landslide action plan (with a push to reach 1:500 scale),
• Updated regulations to guide construction activities in hazardous zones.
• The city’s landslide policy committee is cross-disciplinary in nature, seeking inputs from civic society and university students, with a push to continually update risk zones.

Case of Gangtok, Sikkim:

• The Amrita Vishwa Vidyapeetham has helped set up a real-time landslide monitoring and early warning system, with sensors assessing the impact of rainfall infiltration, water movement and slope instability.

 Flood risks of Indian cities:

• In August 2019, Palava City (Phase I and II) in Dombivli, Maharashtra experienced heavy flooding, leaving residents stranded.
• Seasonal rain is now increasing in intensity.
  • Reason for the flooding:
    • The township, spread over 4,500 acres, was built on the flood plains of the Mothali river.
    • When planned townships are approved, with a distinct lack of concern for natural hazards, such incidents are bound to occur.
  • Floods in Panjim, Goa, in July 2021,led to local rivers swelling and homes being flooded, leaving urban settlements along the Mandovi affected.
    • Issue:
      • The city, built on marshlands, was once home to mangroves and fertile fields, which helped bolster its flood resilience.
    • Delhi: An estimated 9,350 households live in the Yamuna floodplains
    • UN Intergovernmental Panel on Climate Change report of March 2022: highlighted the risk Kolkata faces due to a rise in sea levels.

Measures for Flood-proofing India’s cities:

• Urban planners will have to step back from filling up water bodies, canals and drains.
  • Focus on enhancing sewerage and stormwater drain networks.
• Existing sewerage networks need to be reworked and expanded to enable wastewater drainage in low-lying urban geographies.
• Rivers that overflow need to be desilted regularly along with a push for coastal walls in areas at risk from sea rise.
• Greater spending on flood-resilient architecture(river embankments, flood shelters in coastal areas and flood warning systems) is necessary.
• Protecting “blue infra” areas,, places that act as natural sponges for absorbing surface runoff, allowing groundwater to be recharged, is a must.
• Urban authorities will need to invest in simulation capacity to determine flooding hotspots and flood risk maps.

Way Forward

• The combination of poor urban planning and climate change will mean that many of India’s cities could face devastating flooding.
• Cities need to incorporate environmental planning and enhance natural open spaces.
• Urban master plans need to consider the impact of climate change and extreme weather;
  • Bengaluru needs to think of 125 mm per hour peak rainfall in the future, as against the current 75 mm.
• Urban authorities in India should assess and update disaster risk and preparedness planning.
  • Early warning systems will also be critical.
• Each city needs to have a disaster management framework in place,with large arterial roads that allow people and goods to move freely.