10 Positive and Negative Effects of Landslide

The effects of landslide is a topic that has to be considered because landslide is one of nature’s most destructive forces. The surface constantly reshaping itself and landslides are a major reason they strike wherever the soil is loosened by rain or tugged by gravity. It can be rockfall or a raging river of mud but wherever the ground fails it can result in massive destruction.

On average landslides kill more than 8,000 people every year around the world, they can crash down without warning and travel for several miles. Landslides usually follow natural disasters like volcanic eruptions, earthquakes, wildfires, storms and floods.

Steep slopes and areas that have been hit by landslides before are places landslides can occur. Also, landslides frequently occur where people have radically altered the landscape, hills stripped of vegetation, slopes modified for roads and buildings and as our cities and towns expand further landslides become more frequent and more destructive.

What is Landslide?

A landslide, also known as a landslip, is the movement of a mass of rock, rubble, earth, or soil downslope (soil being a mixture of earth and debris). A landslide occurs when a pile of rock, rubble, or earth slides down a hill. Landslides are a sort of “mass wasting,” which is defined as any downward movement of soil and rock caused by gravity.

A wide range of ground motions, such as rockfalls, deep-seated slope failures, mudflows, and debris flows, can all contribute to mass wasting. The phrase “landslide” refers to a variety of slope movement patterns, including falls, topples, slides, spreads, and flows. These are categorized further based on the type of geologic material (bedrock, debris, or earth).

Typical landslide types include debris flows (also known as mudflows or mudslides) and rockfalls. Landslides can occur in a variety of locations, with steep or gentle slope gradients, ranging from mountain ranges to coastal cliffs, and even underwater, where they are known as submarine landslides.

When gravitational and other types of shear forces within a slope surpass the shear strength (resistance to shearing) of the materials that make up the slope, landslides occur. A landslide is primarily caused by gravity, but there are additional elements that alter slope stability and establish certain conditions that render a slope vulnerable to failure. A specific event (such as severe rainfall, an earthquake, a slope cut to build a road, and many others) often triggers a landslide, though this is not always obvious.

Causes of Landslides

While landslides are considered natural disasters, they have recently become more common due to human-caused environmental changes. Although landslides have a variety of reasons, they all have two things in common: they are caused by gravity and arise from the failure of soil and rock components that make up the hill slope. Causes of landslides include:

• Natural Causes of Landslides
• Human Causes of Landslides

1. Natural Causes of Landslides

The natural causes of landslides include:

• Climate
• Earthquakes
• Weathering 
• Erosion 
• Volcanoes
• Wildfires
• Gravity
• Water

1. Climate

Climate change throughout time can have a considerable impact on soil stability. A decrease in precipitation causes a drop in the water table, a reduction in the overall weight of soil mass, less material solution, and less vigorous freeze-thaw activity.

The level of groundwater would be considerably raised if there was a significant rise in precipitation or ground saturation. Landslides can occur when sloped terrain become entirely saturated with water. The soils begin to flow off if mechanical root support is not provided.

2. Earthquakes

For a long time, seismic activity has been linked to landslides all over the world. A landslide can occur when the Earth’s crust shakes enough to destroy the force of friction that holds sediments in place on an incline. Water can soak into the soil more easily as a result of seismic activity, further undermining the slope.

When tectonic plates move, the soil that covers them moves with them. When earthquakes strike places with steep slopes, the soil often slips, resulting in landslides.

3. Weathering

Weathering is the natural decay of rock that leads to unstable, landslide-prone materials. The chemical activity of water, air, plants, and microbes causes weathering. Landslides occur when the rocks become too weak to support themselves.

4. Erosion

Erosion by sporadic running water sources such as streams, rivers, wind, currents, ice, and waves removes latent and lateral slope stability, making landslides more likely.

5. Volcanoes

Landslides can be triggered by volcanic eruptions. In the event of a wet eruption, the soil will begin to move downhill, causing a landslide. Volcanoes have several properties that make them ideal launching locations for very devastating landslides. A stratovolcano is a kind of volcano that is responsible for the majority of landslides around the world.

6. Wildfires

Wildfires cause soil erosion and floods, both of which can result in landslides. Plants contribute to the stability of the soil by glueing it together with their roots. When the glue is removed, the dirt loosens and gravity has a much easier time acting on it. After a fire, the burned terrain becomes vulnerable to slides due to the removal of vegetation.

7. Gravity

A huge landslide can be triggered by steeper slopes combined with gravitational force.

8. Water

Water reduces friction between the bedrock and the underlying silt, and gravity sends the debris sliding downhill, which is perhaps the most common cause of a landslide. A tiny amount of water may help to promote stability in sand and clay soils. If you’ve ever built a sandcastle or worked with clay, you’ve probably seen this.

However, as additional water is added, the silt becomes heavier, which can lead it to move downhill. This is why so many landslides happen after heavy rains. The most typical cause of a landslide is when water reduces friction between the bedrock and the overlying silt, and gravity sends the debris rolling downhill.

In sand and clay soils, a small amount of water may aid to increase stability. You’ve probably seen this if you’ve ever made a sandcastle or dealt with clay. The silt becomes heavier as more water is added, which might cause it to slide downhill. This is why landslides are so common after heavy rains.

2. Human Causes of Landslides

Some of the human causes of landslides include:

• Mining 
• Clear Cutting

1. Mining

Landslides are frequently caused by mining activities that employ blasting techniques. Vibrations from the explosions have the potential to damage soils in regions prone to landslides. A landslide can occur at any time due to the weakening of the soil.

2. Clear Cutting

Clear cutting is a timber harvesting process that involves removing all of the area’s old trees. This method is risky since it destroys the area’s mechanical root structure. Agriculture and building, which can enhance the risk of a landslide, are two other human-caused landslide causes. Irrigation, deforestation, excavation, and water leakage are all frequent activities that can undermine or destabilize a slope.

Positive Effects of Landslide

Landslides, like all-natural disasters, provide certain vital services. Thus, the positive effects of landslide are:

• Creating New Habitats
• Increasing Biodiversity
• Providing Raw Materials
• Good tools for studying the environment.

1. Create New Habitats

Creating new habitats is one of the positive effects of landslides. Landslides have some good impacts, one of which is the creation of new ecosystems. When landslides occur, the terrain is noticeably altered. Many micro-environments, such as hummocks (hills) and ridges, emerge as a result of this process.

These features may be warmer, drier, or wetter than the surrounding areas, as well as more exposed, less exposed, muddier, and so on. Repeated debris flows and slides can frequently deepen gullies, resulting in increased water flows. As a result, new habitats emerge.

2. Increase Biodiversity

The increase in biodiversity is one of the positive effects of landslides. As a result of these new habitats, biodiversity in that area may rise. It allows organisms to colonize the slide locations and grow or survive as a result. Slides with ridged topography, for example, frequently generate ponds. Beavers have been known to colonize certain areas and produce beaver ponds.

Cliffs can also develop during landslides. These cliffs are so suitable for cavity nesters such as kingfishers and bank swallows. Rodents may also find better hiding places under landslide debris. Furthermore, kauri trees preferentially develop on landslide scars in New Zealand.

3. Provide Raw Materials for:

• Firewood and medicinal plants
• Game berries
• Minerals

Firewood and Medicinal Plants

The provision of raw materials for firewood and medicinal plants is one of the positive effects of landslides. Landslide locations can yield a variety of raw materials, whether immediately after a slide or years later. Residents of tiny farms in Nicaragua, for example, collect fallen Jamaican nettle trees from slides for firewood. Indigenous peoples in India collect medicinal plants like Nardostachys Grandiflora from landslides.

Game and Berries

The provision of raw materials for games and berries is one of the positive effects of landslides. Furthermore, as plants begin to sprout in the slide site, animals get attracted to them. Hunters will be able to pursue wild wildlife to the productive land as a result. Berry pickers, as well as people hunting for firewood, beautiful plants, or medicinal plants, can all benefit from these areas.

Minerals

The provision of raw materials for minerals is one of the positive effects of landslides. Landslides can also disclose mineral reserves. Mineral grains such as gold and diamonds detach over time as a result of weathering. They may congregate at the bottom of slides or near running streams.

4. Tool for Studying the Environment

Landslides acting as a tool for studying the environment is one of the positive effects of landslides. Humans can learn from disasters, as is usual with them. Landslide sites are thus useful instruments for researching the environment in many cases. While geologists examine faults and rock layers using landslides, ecologists research the emergence of plants and their subsequent growth. Bird watchers and scientists may occasionally use these locations for their research.

Negative Effects of Landslides

Landslides have some negative consequences, including damage to ecosystems, crops, physical infrastructure, economic losses, mortality, social upheaval, and the potential for further hazards. the negative effects of landslides include:

• Landslides damage/destroy ecosystems
• Landslides Harm Agriculture
• Damage Built Infrastructure
• Economic Losses
• Loss of Lives and Social Disruption 
• Landslides can Lead to Other Hazards

1. Landslides damage/destroy ecosystems

• Impact on Water Quality
• Wipeout Forest Land
• Dam up or Flood Streams

Impact on Water Quality

The impact on water quality is one of the negative effects of landslides. Landslides have the potential to drastically harm or destroy ecosystems. The impacts can sometimes linger for thousands of years. Sediment and debris can harm streams and water bodies. This always harms water quality and marine life.

Wipeout Forest Land

The wiping-out of forest land is one of the negative effects of landslides. Furthermore, these dangers have the potential to wipe out enormous swaths of forest, wildlife habitats, and rich soils on slopes. An earthquake in Chile in 1960 created many landslides that devastated more than 250 km2 of the forest.

Dam up or Flood Streams

The impact on dams and streams is one of the negative effects of landslides. Landslides can block rivers and streams. Water flow is reduced as a result of this action. Water-dependent marine and terrestrial creatures may eventually perish. Dams, on the other hand, have the potential to flood the other side. Outburst floods can suffocate streams with a massive volume of fresh sediment. Alternatively, they can submerge the flooded area and kill the vegetation.

2. Landslides Harm Agriculture

The impact on agriculture is one of the negative effects of landslides. The devastation of agricultural land is one of the most devastating results of landslides. Debris strewn across farms, fields, and pastures, obliterating valuable agricultural areas. Seeds, plants, food stocks, and grazing areas are all destroyed. These lands can be unavailable for years, putting farmers’ livelihoods at risk. In Guatemala, for example, watersheds were destroyed by landslides caused by Tropical Storm Stan in 2005. As a result, this occurrence had a significant impact on farmers.

3. Damage Built Infrastructure

The damage to built infrastructure is one of the negative effects of landslides. Landslides have the potential to destroy developed infrastructure. They have the potential to demolish and/or damage homes, structures, and infrastructure that is located near hills and mountains. They obstruct highways, train tracks, and shipping lanes. In 1980, a debris flow from Mount St Helens flooded the Columbia River, dumping almost 34 million m3 of silt into the river. Until the mud was dredged, cargo ships could not reach Oregon.

4. Economic Losses

Economic loss is one of the negative effects of landslides. Economic losses as a result of these hazards have been steadily increasing over the last few decades. This is primarily due to increased development and investment in areas prone to landslides. Landslide expenses, in general, include both direct and indirect losses.

Direct losses are the costs of repairing, replacing or maintaining landslide-damaged properties and assets. All additional costs, such as decreased agricultural output, water quality effects, and decreased real estate values, are indirect losses. The devastating Thistle landslide in Utah, United States, in 1983 caused $688 million in direct and indirect economic losses.

5. Loss of Lives and Social Disruption

The loss of lives and social disruption is one of the negative effects of landslides. Landslides have resulted in numerous deaths, injuries, and property damage, including dwellings, infrastructure, and agricultural fields. Each year, landslides kill between 25 and 50 individuals in the United States alone. Between 1279 and 1999, 840 landslides claimed the lives of almost 10,000 persons in Italy.

The majority of the time, disasters strike without notice, leaving people with no time to flee. Such incidents can sometimes have a negative influence on people’s mental health, putting children and teenagers in particular in danger. Furthermore, after being rescued from the debris, landslide victims may acquire crush injuries or crush syndrome.

6. Landslides can Lead to Other Hazards

Landslides leading to other hazards is one of the negative effects of landslides. Tsunamis, volcanic eruptions, wildfires, and earthquakes are frequently triggered by landslides. The 8000-year-old Storegga undersea landslide off the coast of Norway is one of the most famous landslides that caused perplexing tsunami waves. Tsunami waves wreaked havoc on coasts as far as Greenland.

Similarly, a landslide in Vancouver, Canada, in 2007 resulted in 3 million m3 of material being dumped into Chehalis Lake. Several hectares of coastline forest were damaged, and tsunami waves uprooted trees up to 18 meters from the shoreline.

10 Positive and Negative Effects of Landslide – FAQs

Why is Landslide Important?

Landslides are a severe geologic danger that affects nearly every state in the US. As people move into new areas with hilly or mountainous terrain, it’s critical to understand the nature of their potential exposure to landslide hazards, as well as how cities, towns, and counties can plan for land use, new construction engineering, and infrastructure to reduce the costs of living with landslides.

Although many landslides have physical causes that cannot be eradicated, geology investigations, excellent engineering techniques, and efficient enforcement of land-use management regulations can help to mitigate landslide hazards. It’s also crucial to grasp the science of landslides, including their causes, movement characteristics, soil conditions, associated geology, and where they’re most likely to occur.

Are Landslides good for the Earth?

Though landslides often have negative impacts on man, landslides are good for the environment. Landslides help restructure the landscape when was altered by man. Debris flows and other forms of mass movement also play a significant role in feeding silt and coarse woody debris to streams, which helps to maintain pool/riffle habitat. Landslides create a mosaic of seral phases, soils, and sites (from ponds to dry ridges) in wooded landscapes as disturbance agents.

Is Landslide a Natural Disaster?

Yes, landslides are natural disasters, and they are among the most dangerous and unpredictable. Volcanic eruptions, earthquakes, flash floods, landslides, severe thunderstorms, lightning, and wildfires are examples of rapid-onset dangers that arise with little notice and strike quickly.

Why is Landslide a Hazard?

Landslide is a hazard because it has a possibility of causing harm to both the man and his environment. Landslides are downslope ground movements that can cause harm, such as rockfalls, deep slope failure, shallow debris flows, and avalanches.

What are the Vulnerabilities of Landslides?

The vulnerabilities of landslides are the characteristics of the landslide that has the capacity of causing harm. They include velocity, block mass, impact angle of the landslide, the position of the wall impact point, detailed geometry of the wall, and strength of the material.

How do Earthquakes affect Landslides?

By imposing inertial loads or creating a loss of strength in the slope materials, an earthquake can make a slope unstable. Where the landscape is vulnerable to certain types of ground failure, strong earthquake ground shaking greatly increases the likelihood of landslides. When the ground is saturated with water, as it is after heavy rain, the shaking causes more landslides than usual.

Can Plants help prevent Landslides?

Plants can avert landslides. Plants absorb water and minimize infiltration, which would otherwise erode the soil and lead to a landslide. Drought has killed a lot of flora around the world recently, resulting in increased landslides.

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