Modification of seed cell sampling strategy for landslide susceptibility mapping: an application from the Eastern part of the Gallipoli Peninsula (Canakkale, Turkey)

In the literature, different sampling strategies (such as landslide area, seed cell, scarp, point) have been applied to landslide susceptibility mapping studies. Landslide sampling strategy should reflect the pre-failure conditions of failures. Hence, researchers tried to develop sampling methods to provide pre-failure conditions. The main purpose of this study was to modify the seed cell sampling strategy for landslide susceptibility evaluations. Furthermore, landslide susceptibility maps were produced using two different sampling strategies (seed cell and landslide area), and compared in terms of their results. In accordance with these purposes, the eastern part of the Gallipoli Peninsula (Canakkale, Turkey) was selected as the study area in which to apply these two sampling strategies. For the seed cell sampling strategy, different random samplings were prepared by considering different buffer distances and different spatial resolutions. Sensitivity analyses were carried out using the landslide area (with depletion and accumulation zones) and samples and seed cells were acquired from different buffer zones with respect to different resolutions. The spatial performance of the landslide susceptibility maps of both sampling strategies were evaluated using area under the ROC curve (AUC) values. The resulting AUC results obtained from different random samplings and different spatial resolutions indicated that the appropriate buffer distance used to produce seed cells for the evaluation of landslide susceptibility maps in medium scale should be approximately 50 m.