Landslides in mountainous regions are often evaluated as a result of natural processes such as heavy rainfall, steep slopes, and weak geological structures. However, a new study published in the journal Science Advances is of a nature that will significantly change this common perception: A large portion of fatal landslides occur in environments transformed by humans.
According to the study, which analyzed nearly 60 years of land use and 45 years of population data in 46 countries, the impact of human-induced changes such as deforestation, agricultural expansion, and infrastructure construction on landslide-related deaths can be stronger than physical factors like topography and rainfall. Moreover, this impact is not distributed equally globally: Human intervention in mountainous areas reaches up to 50 percent in low and lower-middle-income countries, while it remains at approximately 7 percent in high-income countries. This difference plays a critical role in how fatal landslides become.
Turkey, meanwhile, stands significantly above the average of upper-middle-income countries in human-induced land cover change. It also holds the position of the country where the highest number of landslide-related deaths are seen in Europe.
Human intervention in mountainous areas well above average
Located on the High Anatolian Plateau, Turkey ranks first in Europe when it comes to landslides resulting in death.
According to the study, total human-induced land use and land cover change in mountainous areas in Turkey is at a level of 32 percent. This rate is significantly above the 13 percent average of the upper-middle-income country group in which Turkey is located. In other words, the mountainous landscape of Turkey has been strongly reshaped not only by natural processes but also by long-term human interventions.
The weight of landslide deaths experienced in the country also draws attention. According to the database where data on fatal landslides in Turkey was collected, developed in 2020 by Prof. Dr. Tolga Görüm and Dr. Seçkin Fidan, who are also among the authors of the study, 389 fatal landslide events occurred in the country between 1929 and 2019, and 1,343 people lost their lives.
Additionally, 335 of the 1,375 landslide deaths recorded in Europe during the 1995–2014 period took place in Turkey. These data show that Turkey is one of the most noteworthy countries in Europe in terms of loss of life caused by landslides.
The land change data published in the article regarding land change, which plays an important role in these losses of life, is quite striking.
The data show that the share of forests in mountainous areas in Turkey rose from 13.6 percent to 18.0 percent between 1960 and 2019, but the share of urban areas increased approximately 6.5 times in the same period. Another most prominent transformation is seen in the transitions from grasslands and shrublands, which hold an important place in terms of biodiversity, to pastures and agricultural areas. In other words, the mountainous areas of Turkey are being reshaped not only by forest increase but also by strong and multi-faceted human pressure.
Preventable losses
One of the most important messages put forward by the research is that landslides are not entirely "unavoidable." Although nature-sourced hazards persist, whether these hazards turn into disasters or not depends largely on decisions taken in processes such as land use, planning processes, and risk management policies. At this point, policymakers, local governments, planners, and infrastructure developers assume a critical role.
Measures such as planning land use in a sustainable manner, limiting deforestation, bringing construction in risky areas under control, and developing early warning systems will significantly reduce loss of life caused by landslides, as well as significantly reducing risks against uncertainties brought by climate change.
In conclusion, this new study reveals a vital truth for millions of people living especially in fragile regions: What determines landslide risk is not only nature, but also the relationship humans establish with nature and how this relationship is managed.
(TY)
