Landslide susceptibility assessment of Turkey using qualitative and semi-quantitative methods

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Tezin Türü: Doktora

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Jeoloji Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2013

Öğrenci: KIVANÇ OKALP

Danışman: HALUK AKGÜN

Özet:

Landslides have been studied by using several methods like inventory, heuristic, statistic, and deterministic methods in the recent years; these studies have also been integrated into geographic information systems with the help of technological developments. However, there has not been any nationwide landslide susceptibility zoning map produced for entire Turkey. In this study, assessing the landslide susceptibility of Turkey at a national scale using publicly available datasets was aimed. Two different scaled (1:2,000,000 and 1:500,000) and also two different pixel sized (500 m and 90 m) landslide susceptibility maps have been obtained for entire Turkey using qualitative and semi-quantitative techniques. The larger scaled approach that is composed of different landslide susceptibility maps of the watersheds has been selected after modeling 8-factor and 10- factor based AHP approach that were classified synthetically in a standard procedure developed for this study. Semi-quantitative modeling gives better results than heuristic modeling for the landslide susceptibility assessment of entire Turkey. The governing factors used in semi-quantitative modeling are curvature, landform and earthquake. It is observed that the huge percentage of historical landslides occurred in the topographic wetness index (TWI) layer possessing values of 12 and 13 that were derived from the 90 m resolution DEM. According to the findings Amasya, Sakarya, Muş, Çankırı and Bartın are the most landslide prone provinces of Turkey. The end product of this dissertation can be accepted to be a milestone for producing a final landslide susceptibility map of Turkey.