Human Activity Drives Rise in Deadly Mountain Landslides, Study Finds

A recent analysis, led by the University of Vienna and published in April 2026, revealed a concerning increase in fatal landslides. This phenomenon significantly intensifies in mountainous regions where human activity has transformed the environment. The study highlights that human-induced land-use changes are the primary cause of these tragedies. Consequences are particularly devastating in low and middle-income countries.

Human intervention in mountains destabilizes inclined soils and multiplies the risk of landslides. Actions like deforestation, agricultural expansion, and infrastructure construction are key factors. These transformations alter the natural composition of the terrain, making it more vulnerable.

In less resourced nations, demographic pressure forces many communities to settle in fragile mountainous areas. The need for space for housing, agriculture, and basic services drives this occupation. This exposes populations to constant and growing danger.

Human-induced land-use changes are the primary cause of these tragedies.

The University of Vienna's research analyzed data from 46 countries, covering sixty years of land-use variations and forty-five years of population evolution. Findings confirm that the scale of human intervention is crucial. It explains differences in victim numbers between countries with similar natural risks.

A marked difference exists based on each country's income level. High-income countries modify only about 7% of their mountainous areas. In contrast, low-income nations alter up to 50% of these regions. This disparity is a determining factor in community vulnerability.

Ugur Öztürk, a researcher at the University of Vienna, noted that "in countries like Haiti, Sri Lanka, and El Salvador, this land-use change links to a strong increase in fatal landslides and victim numbers." Seckin Fidan, from Ankara University, added that "economically less favored countries also face great demographic pressure, leading to rapid deforestation and the development of fragile areas for housing, agriculture, and basic infrastructure."

While the relationship between human intervention and mortality is direct in Haiti, Sri Lanka, and El Salvador, nations like Switzerland, Japan, and Italy record significantly fewer fatalities. This occurs despite their exposure to natural risks. The difference lies in more limited human intervention and better land management, along with greater resources for prevention. National income level emerges as a fundamental protective factor.