What Causes Landslides & How Do You Protect Your Property Against Them?

What Causes Landslides & How Do You Protect Your Property Against Them

In regions characterized by mountainous or sloped terrain, the threat of landslides is ever-present. The potential consequences of landslides are substantial, with a single event capable of inflicting millions of dollars in property damage. These occurrences collectively account for nearly a billion dollars in property losses, annually.

These natural disasters can strike without warning. But what are landslides, and what causes them? Is your property at risk? What steps should you take to alleviate this risk? This comprehensive article delves into the intricacies of landslides and explores strategies for mitigating the associated risks.

What Are Landslides?

A landslide refers to the abrupt and often rapid movement of soil, rock, and debris down a slope. The force of gravity plays a fundamental role in causing landslides, leading to the displacement of material from higher elevations to lower areas. These geological events can have severe consequences, posing risks to human life, property, and infrastructure in affected regions.

What Causes Landslides?

As with most natural disasters, the causes of landslides are numerous. It's important to recognize that there is rarely a single factor that precipitates a landslide. The conditions develop over time until a catalyst sets them into motion.


Gravity is the primary driver of a landslide. Over time, the downward force of gravity can cause organic matter to flow downhill. The steeper the slope, the more significant the gravitational force, increasing the likelihood of a landslide occurrence.

Natural Conditions

Many causes can increase the chances of a landslide event occurring. These include:

  • Saturation of water from stormwater or snowmelt
  • Groundwater rising
  • Physical weathering and erosion
  • Earthquakes
  • Volcanic eruptions
  • Deforestation due to wildfires

Human-Made Catalysts

There are also manmade aggravating factors. These include:

  • Deforestation and development
  • Mining and blasting
  • Vibrations from traffic
  • Earth working
  • Agricultural cultivation

These natural conditions and human-made catalysts can result in a less stable slope, ultimately resulting in a landslide. For example, when wildfires occur, they burn away the vegetation and organic materials that hold the soil together, leaving the ground exposed and vulnerable to erosion. The loss of plant roots and protective canopy cover increase the likelihood of soil destabilization during intense rainfall events. Without the roots anchoring the soil, heavy rainfall can easily wash away loose debris, leading to debris flows or shallow landslides.

Landslide Hazard Analysis

The five modes of slope travel that encompass a landslide are toppling, falling, spreading, flowing, and sliding.

  • Toppling: This mode of slope travel involves the forward rotation and movement of a mass of rock or dirt. This generally occurs along an axis at the base of the slope.
  • Falling: This type of movement involves material falling from a cliff or steep slope. It often involves free fall as well as material rolling downward.
  • Spreading: When material flows outward in all directions, it is a spreading type landslide.
  • Flowing: When rock and earth flow like a fluid down a slope, this is called a flowing landslide. There are mud, debris, and rock flow as further subtypes.
  • Sliding: This involves a slip of material unlatching from the rest of the slope and sliding downslope. Sliding is most commonly the deepest type of landslide to occur.

Each of these types of movement can constitute a landslide. Fortunately, things such as landslide hazard assessments can analyze the risk of a landslide occurring on a given piece of real estate. In fact, the U.S. Geologic Survey frequently performs these assessments and publishes the results.

These assessments and the maps that show the results (also called landslide hazard/susceptibility maps) can be invaluable tools in determining whether landslides present a risk to your property and whether you should take steps to mitigate those hazards.

U.S. Landslide Facts and Statistics

According to the U.S. Geological Survey (USGS), landslides cause up to $1 billion in annual damages in the U.S. alone. Domestically, 25 to 50 people die in landslides annually, and hundreds more are injured. During the period from 1998 to 2017. the World Health Organization reported that 4.8 million people were affected by landslides, and 18,000 people were killed.

The five states most prone to landslides are California, Oregon, Washington, Alaska, and Hawaii, but according to the USGS, landslides can occur in all 50 states.

What are the Risks of Landslides to Personal Property?

You may be vulnerable to a landslide if you own a home at the bottom of a slope. In milder cases, you may only experience damage to your landscaping. However, a more significant landslide can destroy property and infrastructure and even pose risk to human life. Here are some of the potential risks you may be facing:

  • Destruction of exterior property – This can include swimming pools, sheds, decks, HVAC units, vehicles, etc.
  • Destruction of your premises – Landslides can damage your foundation, break doors and windows, flood your basement, and even breach the interior of your home.
  • Threat to life – A landslide can be deadly. Children, older adults, disabled persons, and pets are the most vulnerable, but the energy of a massive landslide can be dangerous for anyone.

What Emergency Protective Measures Can a Homeowner Take to Mitigate Personal Property Damage?

If your property is susceptible to landslides, it's essential that you proactively prepare for one. Extreme landslides can pose dire threats that are beyond anyone’s control. In the more likely event of a less severe landslide, there are several methods to mitigate damage and protect your property, ranging from complex construction projects to easy and affordable DIY products.

These steps can help identify which methods can work for your property:

  • Assess Your Risk – Is your property at the bottom of a slope? Has there been natural or artificial deforestation in the area around your property? Are there lakes or bodies of water between your property and the threat? Knowing your risk will help you know how to act. 
  • Check Drainage – Drainage on your property may not entirely protect it from a landslide or mudslide, but it can help redirect water before it saturates the land. 
  • Install a Perimeter Barrier System – These products form a protective barrier between the potential threat and your property, containing solids while slowing and diverting the flow of water. One such product is the EvoGuard Extreme Weather Barrier.

How the EvoGuard Weather Barrier System Works

EvoGuard is a reusable perimeter barrier that can be easily deployed to protect against the ravages of mudslides.

Here's how it works:

  • Installation: The EvoGuard system is installed with positive contact with the earth's surface, creating a physical barrier that traps and contains solids, such as mud and debris flow.
  • Strength and Function: As the system collects solids, the mass and weight increase, enhancing the barrier's strength and functionality.
  • Water Impact: When water impacts the EvoGuard system, its flow is slowed down, and the water distributes evenly across the barrier. This normalized, less destructive flow prevents erosion and minimizes soil detachment.
  • Revegetation and Stabilization: By containing solids and neutralizing the impact of water, the EvoGuard system allows surface areas and slopes to revegetate and stabilize. This contributes to both immediate protection and a long-term solution for eroding land.

The EvoGuard Extreme Weather Barrier system has the following advantages:

  • High Static Bursting Strength: EvoGuard can withstand over 22,000 lbs/sf of static bursting strength, making it highly durable and reliable.
  • Fire-Resistant and UV Protected: The technical mesh used in EvoGuard is rated fire-retardant by the American Society for Testing and Materials and is manufactured with UV protection, ensuring longevity and performance.
  • Rip-Stop Technology: The system is developed with rip-stop technology, allowing for penetration without unraveling. This means that it can endure the impact of an isolated event without weakening or damaging any of the remaining panels.
  • Structural Integrity: EvoGuard is constructed with post sleeves that fully integrate the stakes, maximizing its structural integrity and effectiveness.

Overall, the EvoGuard Extreme Weather Barrier provides a comprehensive and efficient solution for a range of mudslide risks, helping property owners protect their landscapes and assets from damages.

Frequently Asked Questions About Landslides

These are some of the most commonly asked questions about landslides and preventing landslide damage:

How Can I Protect My Property From a Landslide?

By providing a robust physical barrier and utilizing high-strength materials, the EvoGuard Extreme Weather Barrier system effectively blocks and contains soil, rocks, and debris that could otherwise cause extensive damage during a landslide event.

How Can One Person Install an EvoGuard Barrier?

The system is lightweight and designed for easy installation. If you can follow simple directions and swing a hammer, you can install an EvoGuard barrier. The EvoGuard Extreme Weather Barrier DIY Kit comes with everything you need to be successful, even on your own. For larger or commercial projects, EvoGuard Pro is better suited for the job and it may be helpful to have a partner or a team.

Can I Use More than one EvoGuard Weather Barrier System?

Absolutely! EvoGuard barriers can be combined for larger properties, and excess mesh can be easily rolled into the final stake. EvoGuard's Resources page has a video on how to link barriers and secure remaining material.

DIY Home Landslide Protection

Unlike other perimeter barrier systems, the EvoGuard Extreme Weather Barrier has a technical mesh that is constructed with post sleeves that fully integrate the stakes into the system, maximizing its structural integrity. To learn more, contact EvoGuard's weather barrier provider experts today!