Summer of 2023 was brutal for a lot of North Indian regions in India. Over 100 people have already died in incidents related to flash floods and landslides, especially in Himachal. While people are aware about flash floods, very little awareness is there about landslides and why they happen.
That’s why Helplocal – the best place to discover local NGOs in India – decided to create a knowledge resource on why landslides happen and how to stop them. Read on to discover all the scientific reasons behind landslides and ways to curb them. Before anything else, let’s learn what are landslides.
What are landslides?
The term landslide generally refers to downhill movement of rock, soil, or the earth down a slope. The downslide movement of rock and soil under the influence of gravity is known as landslide. There are mainly two types of landslides- Mudslides and rock falls.
Landslides are pretty common in hilly regions, especially during the monsoon reason but the instances on landslips have grown in the past decade. Let’s now discover why landslides happen.
Why landslides happen?
The main reason for the landslides is GRAVITY, WATER AND FRICTION. The main reason for a landslide is the gravitational force acting on an over-steepened slope.
The role of gravity
A landslide occurs because the force of gravity becomes greater than both the frictional force and the internal strength of the rock, soil and sediment. Landslides generally move down because the gravitational force pulls the material downhill from the slope. The two factors responsible for this are mainly – 1. The frictional force of the material on the slope. 2. The internal strength of the material.
The role of water
Water plays a great role in this process as the addition of water on the slopes make the landslides very common because it adds significant weight to the slope lowers the strength of the material which makes it less stable and as a result it becomes difficult for them to withstand the force of gravity. Water also reduces friction making it easier to move material downhill.
The role of friction
The frictional force that acts between the deposition of the rocks and the slope that it rests on plays a great role when landslides happen. In the case of landslides the steeper slopes have less friction making landslides very common. Pushing the rocks is easier if the surface slopes downhill or is slippery.
Manmade triggers for landslides
While above are the reasons why landslides happen, humans have made the phenomenon more common by creating additional triggers. Some of these triggers quicken the natural process. Here are the major triggers that have made landslides more common in 2023
- Erosion of soil due to rivers, glaciers or waves from the ocean that creates over – steepened slopes.
- Weakening of rocks and soil slopes due to heavy rain and snowmelt.
- Excess weight from the accumulation of waste piles, man- made activities, ore, rain or snow causes weak slopes.
- Volcanic eruptions that deposit ash and debris flows cause weakening of land.
- Deforestation in hilly regions escalates the risk of landslides
- Destruction of hills for expansion of road and rail network is one of the major reasons why landslides are happening more often.
When slope material mixes with water, it may develop a debris flow or mud flow. This slurry of rock and mud pulls trees, houses, and cars and blocks bridges.
Earthquakes with magnitude 4.0 or greater are also a major reason behind landslides.
In the last 5 years, over 1553 people have lost their lives to landslides, floods, and related occurrences in Himachal alone. Therefore, it’s high time to become proactive.
How to prevent landslides in 2023
There is a lot that can be done to reduce the landslide hazards. Some preventive measures like good engineering practices, physical and geological investigations and land use management acts and regulations can be taken to reduce the effect. While natural causes of landslides cannot be removed, some effective enforcement of the land can overcome its side-effects.
So, if you are living in an area that’s prone to landslides, some steps should be followed strictly to protect your life and property.
Let’s take a look at them:
Check for slopes
Remove your property from the slope i.e near to rocks, debris, fallen trees this will cause great risk for the property in case of landslide.Limit property damage risks by moving the material away from the sloppy areas.
Check for loose material: Always place loose material like cans, scrap woods, spare parts etc. junks away from the top of the hill because they can slide down the hill and can cause heavy damage.Also void dumping water on the top as it causes soil erosion.
New properties check
While going for the construction of a new building, make sure it’s far away from edge of the slope.Before constructing any building observe the area well to make sure it’s at a safe distance.
Go for vegetation
Don’t cut the trees that are on the edge of the slope. Instead, nourishing them is a great practice to check soil erosion.To prevent erosion, go for more-and-more trees, herbs and tall grasses.
Create boundaries
Build a massive wall around your house if you are in a landslide prone area. A huge wall works as a barrier between the house and the flow from the hills. The drainage should be built in such a way that the debris must flow away from the main building thus protecting it from landslide.
Control water flow
The water flow from the buildings must be regulated properly in such a way that it must not erode the soil as if erosion occurs it makes the soil strength weaker.Check for the water leakage from the pipes regularly.
Avoid sprinklers
Don’t use a sprinkler irrigation system on the hill slopes as it’s responsible for the erosion of soil.This system can make the land unstable and thus leads to heavy flow in case of landslide occurrence.
Premium pipes
Use flexible leak proof pipes to prevent water leakage at the hills. These pipes don’t crack and make sure that the water supply in the area would be continued at the time of hazard.
Regulate flow
The drainage must be in such a way that it must be towards the end of the slope not in the middle because the running water when left open in the middle causes loosening of soil.Search for the natural runoff areas for fast regulation of water.
Create diversion
If you live in a landslide prone area, make sure to dig a ditch to divert the path of the debris.Try to make a diversion away from your building to protect your property from damage.
Strenthning The Ground
Remove loose soil from the hills regularly Go for loose soil replacements since this will make your property safe from landslides.
Why landslides happen and how to stop them
By adopting the above methods to check instances of landslides, we can reduce the life risk as well as property damage. Follow the instructions given by the authorities and take all the precautions seriously to avoid any further damage.
Landslide is a natural process but preventive measures taken at regular intervals of time will surely minimize the risk of the hazard.
Go for afforestation, deploy rainwater harvesting, check forest damage, and advocate sustainable economic development to make sure that your region is not affected by landslides and other natural calamities.
Speak with your local authorities to find out if you live in a landslide and flooding prone region. If you are in Himachal, you can simply check this resource to see which HP areas are more prone to landslides.
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Thanks for reading.
About Contributing Author:
I’m Rashi Sharma, an avid reader in love with writing. I always felt like I have many thoughts in my mind, and writing helps me make sense of the world. Currently, I live in Himachal and want to change the world with my keyboard.
