Comprehensive landslide hazard assessment using spatial, temporal and size probabilities combined with landslide density analysis in Çanakkale (NW Türkiye)

Abstract

To assess the landslide hazard (LH) of the area between Lapseki and Güzelyalı (Çanakkale, NW Türkiye) the LH map and the landslide density hazard map were produced. The LH maps produced in this study were calculated by multiplying the spatial probability, size probability, and temporal probability. The landslide susceptibility (LS) map was produced using the Random Forest method. While producing the LS map, elevation, land use, curvature, lithology, NDVI, distance to streams, slope, TWI, and aspect were used as input parameters. The rainfall triggering landslides was obtained as 220 mm. Using Gumbel distribution, the exceedance probability of the 220 mm rainfall value in 5, 10, 25, and 50 years were calculated as 0.453, 0.701, 0.951, and 0.997, respectively. The probability of occurrence of a landslide that is equal to or greater than a selected area was found using landslide frequency-area distribution. The probability of a landslide in the study area, surpassing an area of 0.1 km², an area of 0,35 km², and an area of 1 km², with corresponding probabilities of 0.701, 0,361, and 0.184, respectively. To solve questions about where and how densely potential landslides will occur at a given time, a landslide density hazard map was produced. The Landslide density hazard map was calculated from the spatial probability, landslide density, and temporal probability. It was seen in this study that the landslide hazard concept should be considered by the decision makers for the future works such as land-use management and urban development strategies.