The concentration of the population in urban centers throughout the world necessitates the introduction of new settlements areas in certain regions. However, the fact that natural disasters are not sufficiently considered when selecting new settlement areas causes thousands of people to die as a result of many disasters and causes enormous material damage. Landslides, one of the natural disasters in question, cause great damage and loss of lives every year around the world.
When evaluated on a global scale, an area of 3.7 million km2 is exposed to landslides, and approximately 300 million people live in these areas. When examining at the Europe and Central Asia scales, the highest number of people exposed to landslides live in Turkey. In the last 50 years, 13,494 landslides have occurred in Turkey, and the total number of disaster victims affected by landslides has been recorded as 59,345 (Fidan 2019).
The main reason why landslides are extremely dangerous is that they can occur in a short period of time and cause many casualties. For example, on July 5, 1929, 148 people lost their lives as a result of the landslides that occurred around the districts of Of and Sürmene in Trabzon Province due to heavy rainfall that lasted for days (Fidan, 2019). Although landslides can occur in almost every region of Turkey, the Black Sea region is the most susceptible to landslides. The reason being that the Black Sea region has a mountainous topography, receives heavy rainfalls, and is close to the North Anatolian Fault Line (Yaman 2017; Kilicoglu et al. 2020).
Floods, which are among the natural disasters evaluated within the scope of this study, are disasters that can affect extensive areas and cause great material damage. Approximately 3 million people lost their lives in the flood events that occurred between 1900 and 2008 around the world, 2 billion people were affected, and cost of the material damage was approximately 200 billion USD. Approximately 49% of the 560 thousand people who lost their lives as a result of various natural disasters (e.g. floods, earthquakes, fires, storms, and volcanic eruptions) in the last 20 years is because of floods and overflows (Dölek 2013).
Floods and overflows, just like landslides, can cause a loss of numerous lives in a short period of time and result in great material damage. It has been reported that the hurricane Harvey and subsequent flooding in the USA damaged more than 204,000 buildings and caused approximately 125 billion USD in loss; the flood that occurred in Pakistan’s eastern Hindu Kush region in 2010 killed approximately 1800 people and cost tens of billions of USD; and the floods that occurred in China in 2010 caused approximately 50 billion USD damage (Mukherjee and Singh 2019; Mahmood et al. 2019).
Floods and overflows are frequently seen in Turkey and can cause significant loss of life and material. In 695 flood events that took place in Turkey between 1975 and 2010, 634 people died, 810,000 hectares of land was submerged, and approximately 3.7 billion USD material damage occurred (Dölek 2013). Moreover, flood and overflow events will increase in the coming years in Turkey, which is among the countries that will be most affected by global climate change (Demirbaş and Aydın 2020; Cetin 2020).
Although landslides, floods, and overflows threaten the safety of the life and property of people, flood and overflow risks are not adequately evaluated during the selection of settlement areas; consequently, caused by the landslides, floods, and overflows, significant material damage and loss of life may happen. However, most of these losses can be prevented by conducting preliminary studies in the selection of suitable settlement areas.
Another criterion to be considered in the selection of settlement areas is biocomfort. In short, biocomfort, which can be explained as the environmental conditions (temperature, wind speed, and humidity) in which people feel comfortable, is of great importance, especially in terms of energy consumption; moreover, it affects people’s health, comfort, productivity, and psychology (Adiguzel et al. 2020; Cetin 2019; Gungor et al. 2021).
People use various heating and cooling devices to create appropriate biocomfort conditions in their environment; consequently, the amount of energy spent varies significantly depending on the biocomfort conditions. It is estimated that worldwide energy consumption will be approximately 60% higher in 2030 than it is today, and this increase will reach 100% in Turkey. In this energy consumption, the amount spent for heating and cooling has a significant proportion (Cetin et al. 2018; Zeren Cetin and Sevik 2020). Therefore, the establishment of settlement areas in places suitable for biocomfort is of great importance for energy efficiency as well as human health, comfort, happiness, productivity, and psychology (Potchter et al. 2018).
In the selection of settlement areas, identifying the safe areas considering natural disasters in the region first and then determining the suitable areas in terms of biocomfort is logical. However, the number of studies conducted by considering multicriteria in the selection of settlement areas is almost nonexistent. In the case studies conducted on this subject, Kilicoglu et al. (2020) identified the risk of floods and overflows from natural disasters, protected areas, high-voltage energy transmission lines, and suitable areas in terms of biocomfort in Bafra; according to these criteria, he stated that only 1.96% of the total study area is suitable to be used as settlement areas. In another study conducted in Atakum, in conclusion of calculations performed considering the landslide and flood risks, as well as the high-voltage energy transmission lines and biocomfort, it was calculated that only 15.11% of the study area is suitable to be used as a settlement area (Kilicoglu et al. 2021). In contrast, the present study stands out as it is one of the first studies in which priority ranking is considered in the selection of settlement areas according to multicriteria.