By Ayushi Gupta ~ University of Petroleum and Energy Studies

Introduction

The occurrences of landslides around the world have disastrous impacts. From the landslides in the mountains of Uttarakhand to the recent Kerala landslides, it causes enormous loss to life and property. With this pretext, the author discusses the various causes for the incidence of landslides and its effects on the environment as well human beings, along with a brief overview of the regulatory systems in place in the country.

A landslide generally occurs due to the fast or slow movement of earthly materials such as rock boulders, soils or snow blocks in mountains and hilly regions owing to the gravitational influence. The following are the various causes of landslides:[1]

  1. Geologically Weak Material: Weakness within the composition or structure of a rock or soil.
  2. Erosion of Slope Toe: Lowering of vegetation and construction of roads increases the vulnerability of the terrain to slip down.
  3. Intense Rainfall: Storms that lead to rainfalls ranging from shorter periods to a more moderate intensity rainfall lasting for several days trigger landslides. The heavy melting of snow in the hilly terrains also results in landslides.
  4.  Human Excavation of slope and its toe, drawdown within reservoirs, mining, deforestation, irrigation and water leakage from the surface are few other causes of landslides.
  5. Earthquakes have triggered soil slides and rockslides in steep slopes involving relatively thin or shallow disaggregated soils or rocks in various topographic and geologic settings.
  6. Deposition of loose volcanic ash on hillsides followed by accelerated erosion, along with the flow of mud or debris is triggered by intense rainfall.

Impacts of Landslides

Landslides are as deadly as other natural catastrophes but receive far less attention due to the negligent conduct of people who do not consider the threats and consequences of a possible landslide before going ahead with reckless constructions in the hills. Reality often dawns too late in the day.

An international database[2] of fatal landslides that have occurred across the globe from 2004 to 2016 prepared by the University of Sheffield shows that approximately 11,000 deaths have been caused due to landslides in 12 years, with India topping the list with more than 56,000 casualties from 4,800 landslides around the world. India not only accounts for 20% of the landslide deaths but also has the dubious distinction of witnessing the fastest rise in human-triggered fatal landslides. The main causes of such triggers are legal and illegal mining, hill cutting, construction, dam collapse and pipe leaking.[3] In the case of the unprecedented floods and landslide that occurred in Uttarakhand in 2013,[4] extreme rainfall triggered numerous landslides and caused widespread damage to property and life in the Bhagirathi and Alaknanda river valleys, with Kedarnath town bearing the brunt of the disaster.

The landslides that occurred in Kerala and parts of Karnataka due to extreme rainfall measured an average of 50-100 sqm.[5] Dave Petley who is the Pro-Vice-Chancellor (Research and Innovation) at the University of Sheffield observed that “Kerala and parts of Karnataka are undoubtedly naturally landslide-prone because of the mixture of monsoon rainfall and upland areas. But human activities are exacerbating these problems. The occupation of dangerous areas, inadequate water management, poor construction practices, construction, quarrying, and hill cutting all contribute to increased landslide hazard. [6]

Provisions in Law

In order to mitigate the disastrous impacts of a landslide, first, the hazard must be recognized, and the danger should be analyzed, followed by the formulation of an appropriate strategy. The National Disaster Management Authority (NDMA) has prepared a comprehensive guideline for disaster management of landslides and snow avalanches after a series of consultations to guide the activities envisaged for mitigating the dangers emanating from landslides.[7] The principles include regulatory and non-regulatory frameworks with a definite time frame to conduct all the activities. The envisioned disaster management plan and policies operate at both national and state levels.

The Supreme Court, in the case of Gaurav Kumar Bansal vs. Union of India, [8] suggested that the NDMA has to publish its Annual Report regularly and should review and updates its plans. In addition to this, the court has also added that the authority should create a multilingual website for the benefit of people. In the Case of Alaknanda Hydro Power Company Ltd (AHPCL) vs. Anuj Joshi and Ors,[9] the court held that AHPCL should monitor its project during construction and post-construction by taking into account various parameters such as water quality, aquatic biodiversity, landslides in the rim area, inflow and outflow, impacts on water tables and springs. The court directed AHPCL to submit the report relating to the same to the Ministry of Environment, Forest and Climate Change, Government of India as well as the concerned State Government.

In the case of Betqui Candola Samvardhan Samitee vs. Gera Developments Pvt. Ltd. and Ors,[10] the court observed that the laws regulating construction on slopes were not mere formalities. The court emphasized on the duty of authorities to ensure that uncontrolled constructions on the slopes do not lead to disasters. In the present case, the court held that the Chief Town Planner has to conduct a joint survey and obtain an authentic contour plan to be fully satisfied before allowing for large scale construction projects.

In 2015, the Indian National Academy of Engineering (INAE) convened a round-table meeting of landslide experts in New Delhi and gave the following suggestions to resolve this major problem which are[11]:

  1. To establish a national centre for landslide management
  2. To prepare multi-tier, dynamic and holistic short, medium and long-term landslide management plans;
  3. To launch a national program to manage major landslides;
  4. To make sure that DPRS(Department of Protective and Regulatory Services) are eco-friendly and techno-economically sound;
  5. To enforce the analysis of technological options;
  6. To connect landslide investigation with landslide management;
  7. To promote community-centric early warning;
  8. To review and revise NDMA guidelines and landslide related BIS codes;
  9. To accord the very best priority to R&D; and
  10. To prepare monographs on landslide disasters.

Conclusion

Unlike earthquakes and tsunamis, most landslides are preventable and controllable, if managed with appropriate interventions of science and technology. Millions of people around the world lose their lives because of natural disasters, and Landslides approximately affects 15% of the landmass.[12] Even though at times landslides cannot be predicted, they can certainly be prevented through various measures taken by the government and the people living in the affected areas. Disaster management of landslides is a vital step towards mitigating the harmful consequences of the event which needs to be practised by all individuals, including the communities affected in pre and post-disaster situations.

Citations


Landslides: A Silent Killer

One thought on “Landslides: A Silent Killer

  • September 28, 2020 at 5:06 am
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    Great article

    Reply

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