Impact of Landslides in Uttarakhand | 28 Sep 2024

Why in News?

The Badrinath National Highway (NH-7) in Chamoli district has been repeatedly blocked due to heavy rainfall, causing landslides and debris accumulation.

Key Points

• The India Meteorological Department (IMD) has predicted more isolated heavy rainfall in Uttarakhand which could potentially cause further disruptions.
• Landslide:
  • A landslide is a geological phenomenon involving the downward movement of a mass of rock, soil, and debris on a slope.
  • Landslides can occur on both natural and man-made slopes, and they are often triggered by a combination of factors such as heavy rainfall, earthquakes, volcanic activity, human activities (such as construction or mining), and changes in groundwater levels.
  • Landslides are classified into several types based on their movement characteristics:
    • Slides: These are movements of soil or rock along a rupture surface or a zone of weakness. They can be further divided into rotational slides, where the rupture surface is curved, and translational slides, where the rupture surface is planar.
    • Flows: These are movements of soil or rock that contain a large amount of water, which makes the mass flow like a fluid. They can be further divided into earth flows, debris flows, mudflows, and creep, depending on the material and the rate of movement.
    • Spreads: These are movements of soil or rock that involve lateral extension and cracking of the mass. They are usually caused by liquefaction or plastic deformation of the material.
    • Topples: These are movements of soil or rock that involve forward rotation and free-fall of the mass from a vertical or near-vertical cliff or slope.
    • Falls: These are movements of soil or rock that detach from a steep slope or cliff and descend by free-fall, bouncing, or rolling.