Think and Grow Rich

Saturday, May 6, 2023

Land slides - causes, effects and remedial measures

 


Landslide is the movement  of a mass of rock or soil along a slope. Landslide occur   when gravitational and other types of forces within a slope exceed the strength  of the mass of the materials inside the slope. The forces with in the slope can  be of various types like natural erosion, excavation, torrential rain or earthquakes.

Types of landslides

Land slides are classified depending on the type of material and the type of movement of the material.

Type of movement - slides, flows, spreads, topples

Type of material- rock, debris, soil

There are rock slides and mud slides. If the overlying material moves as a single mass, it is called block slide. A type of landslide in which the  particles move similar to that of a viscous fluid it is called a flow. The most common fluid is water. A spread is the lateral movement of the coherent soil resting on a weaker substrata. Spreads occur as the result of liquefaction caused by water saturation or earthquake. Topple failures involve the forward rotation and movement of a mass of rock earth or debris out of a slope.

Causes of land slides

Heavy rain

Earth quake

Deforestation

Construction activities in mountainous regions

Effects of landslides

Loss of life and property

Shifting of general public

Loss of fertile land

Damage of railway track and highways

Diversion of river water causing floods

Environmental problems

Remedial measures

Installation of early warning systems

Identify probable locations of landslide

Afforestation

Draw  specific codes for construction of buildings in the concerned areas

Insurance policies for the affected people

Terrace farming in the hilly areas

Improving drainage

Reduce the angle of the slope

Protective wall at the bottom of the slope

Deployment of rescue personnel in case of emergency

Zones of vulnerability

India is divided into four zones of vulnerability.

Very high: Himalayas, Andaman and Nicobar islands, NE region, Western Ghats

High:    Areas of very high vulnerability except plains of Assam

Low:     Ladakh, Himachal Pradesh, Aravalli mountains, Deccan plateau

Other areas: Remaining parts of India

 Some major landslides

India

Kedarnath (June 2013) 4000 people died

Dehradun (May 2016) 10 people died

Manipur (June 2022)  58 people died

Kerala (September 2021) 39 people died

Maharashtra (July 2021) 36 people died

Abroad

California, USA (September 2022) 20 people died

Durban, South Africa (April 2022) 443 people died,40000 displaced

https://youtu.be/fb1dSUFugYs

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1 comment:

  1. Wow! Very informative. And timely, too, given what happened in Wayanad. Thanks for sharing it.

    ReplyDelete