Landslides and Mudslides: Causes, Prevention, and Mitigation

Landslides and mudslides are naturally caused by the movement of soil, rocks, or any type of debris down a slope. These events spell significant risks to people and public infrastructure. Such events can occur fast, too fast, often with no warning, and can reach incredible speeds of 55 to 100 miles per hour. In the United States alone, landslides and mudslides result in 25 to 50 fatalities annually, clearly indicating how big of a threat they are.

Landslides and mudslides can be triggered by both natural and human-induced factors. The primary trigger in question is heavy rainfall or rapid snowmelt, which can lead to the accumulation of water within the ground, saturating the soil and underlying materials. This increases the weight of the slope and reduces its strength, making it more unstable. Earthquakes and volcanic activity can also destabilise slopes, causing landslides through ground shaking. Human activities such as construction and deforestation contribute a high percentage to the risk of landslides by removing vegetation that anchors the soil, altering natural drainage patterns, and disturbing previously stable slopes.

Effective prevention strategies play a huge role in minimizing the risk of landslides and mudslides. Planting ground cover and native trees on slopes helps to stabilize the land by reinforcing the soil structure and reducing erosion. Avoiding cuts and fills on steep slopes during construction greatly reduces the potential for instability by preserving the natural contours of the land. Directing surface runoff away from vulnerable slopes through the construction of drainage channels can prevent water from accumulating in the ground and saturating the soil. Regrading slopes to make them less steep is another effective method for reducing erosion and improving slope stability.
Prevention is one thing, while mitigation is another. Many mitigation techniques can be used too to protect property and infrastructure from the havoc caused by landslides and mudslides. Construction of retaining walls can provide support to unstable slopes, preventing soil and debris from moving downhill. Ameliorating drainage through the installation of drainage pipes, ditches, and berms helps to drain the water from the soil. This leads to increased soil stability. The use of sandbags and K-rails can provide temporary protection by diverting the flow debris. Adhering to evacuation plans, and staying on high alert to warning signs like cracks in the ground, or leaning trees, even normal people can take the right steps to evade dire consequences. These preparations can make a real difference when disaster strikes.

By: Akshaj Medicharla