Morphological parameters causing landslides: A case study of elevation

The history of landslide susceptibility maps goes back about 50 years. Hazard and risk maps later followed these maps. Inventory maps provide the source of all these. There are different parameters selected specially for each field in the literature as well as parameters selected because they are easy to produce and obtain data. This study tried to research the effect of elevation on landslides by reviewing the literature in detail. The used class ranges and elevation values were reviewed and applied to map sections selected from Turkey. By analyzing the results, the goal was to determine at which elevation ranges landslides occurred. The study tried to investigate the effect of the parameter of elevation using data from the literature. It works to compare the elevation values for map sections selected to compare with the literature. The study comprises two stages. The first step tried to acquire statistical data by researching the data from the literature. The data were investigated in the second stage. For this purpose, close to 1.500 studies prepared between 1967 and 2019 were reviewed. According to the literature, the parameter of was used in analyses because it is easy to produce and is morphologically effective

Effect of the slope angle and its classification on landslides

The preparation of landslide susceptibility maps is a complex process with regards to selection of study field, parameters, and methods. The phase after the determination of the landslide distribution in landslide susceptibility studies is selection of methods and parameters to be used. A review of approximately 1500 randomly selected publications revealed that it was necessary to select a parameter based on the area, in each study, the most preferred parameter was the slope angle. Generally, it was observed that automatic slope angle classifications were used in the preparation of landslide maps. Therefore, there is no standard in slope angle maps nor in the class range that is referenced when preparing them. In this study, class ranges and slope angle values of areas where landslides have occurred were determined from the 15 literature, and of these, 40 landslides areas were selected in Turkey and their slope angle maps were created. These were evaluated based on the slope angle classes determined in the published literature. The effects of slope angle on the landslide were determined, and an understanding was gained of how important it was to be careful when determining the classification of slope angle. When smaller class ranges were selected, different results were obtained suggesting that the selection of the range of classes are vital in the preparation of landslide susceptibility maps

Utilization and Application of AHP Method in Landslide Susceptibility Mapping Production (Sinop and its Surroundings)

Bilgisayar destekli haritalama teknolojileri ve bunların geliştirilmesinde kullanılan yöntemlerde meydana gelen gelişmeler, daha yüksek performansa sahip heyelan duyarlılık haritalarının üretilmesini sağlamıştır. Bu çalışmada, bu yöntemlerden biri olan AHP'nin (Analitik Hiyerarşi Süreci) heyelan duyarlılık haritalarının üretilmesinde kullanımına ilişkin ayrıntılı bir literatür derlemesi yapılmış, ayrıca AHP ile Sinop ve çevresinin heyelan duyarlılık değerlendirilmesi gerçekleştirilmiştir. Heyelan duyarlılığının değerlendirilmesinde bakı, litoloji, arazi kullanım sınıfı, yamaç eğriselliği, eğim, yükseklik, anayola, akarsuya ve yapısal unsurlara yakınlık, çalışma sahasında heyelanları kontrol eden faktörler olarak dikkate alınmıştır. Kullanılan faktörler ağırlık değerlerine göre grid haritalarına dönüştürülmüş ve karşılaştırma matrisindeki değerlerin değişik şekillerde ele alınması ile çeşitli heyelan duyarlılık haritaları üretilmiştir. Analiz sonuçları, heyelanları temelde kontrol eden faktörlerin anayola uzaklık, bakı ve litoloji olduğunu göstermiştir. Sonuç olarak, heyelan duyarlılığı açısından Sinop ve yakın çevresindeki çalışma sahasının, % 10.77'sinin çok düşük derecede heyelana duyarlı, % 10.59'unun düşük derecede heyelana duyarlı, % 52.64'ünün orta derecede heyelana duyarlı, %25.66'sının yüksek derecede, % 0.34'ünün çok yüksek derecede heyelana duyarlı olduğu belirlenmiştir. Bu çalışma sonucunda, özellikle son yıllarda artan biçimde kullanılan AHP'nin çalışma alanı için yüksek performans sağladığı saptanmıştırComputer-aided mapping technologies and developments used in improvement of these methods have led to the production of higher performing landslide susceptibility maps. In this study, a thorough review of the literature about the production of landslide susceptibility maps by using AHP (Analytic Hierarchy Process) was made and, also, landslide susceptibility evaluation of Sinop and its surroundings was analyzed by AHP. In the evaluation of landslide susceptibility factors such as aspect, lithology, land use, curvature, slope, elevation and proximity to the main road, river and structural elements are considered to be controlling factors in the landslide process. These factors are turned into grid maps according to their weighted values and by handling the values in comparison matrices in different manners, and variety of landslide susceptibility maps produced. Analysis of results showed that main controlling factors of landslides are the proximity to main road, aspect and lithology. As a result, in terms of landslide susceptibility, very low landslide susceptibility is determined in the 10.77%, low landslide susceptibility determined in the 10.59%, moderate landslide susceptibility is determined in the 52.64%, high landslide susceptibility determined in the 25.66%, very high landslide susceptibility determined in the 0.34%, of Sinop and its proximity area. This study reveal that AHP, which has been used increasingly in the last years, provides high performance in the study are