Landslides are exactly what they sound like: land, debris, or pieces of earth sliding down a slope from a higher point. The term landslide refers to mudslides, mudflows, debris flows, avalanches, and rock slides. The occurrence can happen quickly or slowly, lasting from a few seconds to longer periods. 

Additionally, landslide events can happen anywhere and often occur where they have happened in the past. Furthermore, predicting a landslide’s occurrence and duration can be challenging, although some natural events and human activities can provoke one. 

This article will reveal the causes of landslide events, discuss warning signs, and list ways to prepare for one. So this leads us to the big question: 

Can landslides happen because of wildfires?

Truth: Landslides can happen because of wildfires. Burned areas are particularly susceptible to sliding. Burned roots loosen up the soil, which becomes saturated with heavy rains and creates a high risk for a landslide. 

Let’s look at some examples of landslides occurring post-wildfire in Southern California.

Montecito

On January 9th, 2018, mudslides and debris roared down the hillsides of Santa Ynez, a small town in Montecito. The landslides occurred in an area previously burned by the Thomas Fire. Mud and debris began to flow after a heavy overnight storm consisting of a torrential downpour. The damage was devastating, with properties destroyed, 23 deaths, and hundreds injured. 

Malibu

Also in 2018, Malibu witnessed several mudslides after a winter storm dumped snow and rain on an area burnt by the Woolsey Fire. Thankfully, no one was hurt by the slides. 

Other Causes of Landslides

Apart from wildfire damage, landslides are also caused by earthquakes, volcanic activity, heavy rain, and snowmelt after a winter storm. In addition, human interaction with the landscape, such as excavation, construction, removing vegetation, or changing water flow, can exacerbate landslide conditions. 

Other conditions that favor the occurrence of landslides are slopes greater than 10 degrees and where the height from the top of the hill to the lowest point is greater than 40 feet. Slopes with low vegetation or high soil water content are also more likely to slide.

Landslide Warning Signs

Take precautionary measures

• New or widening cracks on the pavement or ground
• Pavement collapses, or rocks and mud are on roads
• New cracks in or on buildings
• Soil moves away from the foundation
• Exterior walls, paths, or stairs move away from buildings
• Underground utility lines or water lines break
• Landscape changes, such as stormwater drainage on slopes, land movement, small slides, or rapidly leaning trees
• A rapid increase or sudden decrease in river or creek water levels
• Bulging ground appears at the bottom of a slope
• Vertical objects such as fences or trees move or tilt

Signs a Landslide is Occurring Right Now

Evacuate immediately

• A faint rumbling sound with increasing volume
• The ground begins sloping or shifting downward in one direction
• Unusual sounds occur, such as trees cracking or boulders knocking together

How to Prepare for Landslides

While most landslides occur unexpectedly, there are some things you can do to prepare.

1. Stay Alert

During and following intense rainfall, stay alert to landslide warning signs and listen to the local radio or TV for any updates. 

We also know landslides commonly occur after natural disasters such as earthquakes, wildfires, and volcanic activity. So if one of these disasters occurs near your area, especially if it’s followed by storms or heavy rain, be alert to the possibility of a landslide. 

2. Know the Risk

When buying a property or home, know the slide risk in the area. Some areas are more vulnerable to landslides than others. 

3. Prepare for Evacuation

Build an emergency supply kit and prepare an evacuation plan.

4. Obey Land-Use Procedures

Avoid building at the base of a slope, close to mountain edges, and in water drainage paths. 

5. Protect Your Property

Consider building a retaining wall or planting ground cover on steep slopes.