GIS tools application for landslides formation factors analysis (Transcarpathian region)

Abstract

Summary Landslides are among the most common exogenous geological processes that have developed in Transcarpathian region. Therefore, they were included in the list of hazardous geological processes being analyzed within the project Improving Disaster Risk Reduction in Transcarpathian Region, Ukraine (ImProDiReT) (grant №783232 for the competition UCPM-2017-PP-AG DG-ECHO). In order to identify the main and derived geological factors that determine landslides propagation and activation in the Transcarpathia, 2 575 landslides of more than 3 300 known in the region were analyzed, with a total area of 360 576 sq. km. Initial information for the factors analysis is represented by: 1) database and landslides inventory map for Transcarpathian region; 2) relief horizontals which are corresponding to the topographical background of scale 1 : 100 000 and 3) the tectonic disturbance map derived from a geological map of scale 1 : 100 000. Factors were represented in ArcView Spatial Analyst generated grids: relief and its derivatives (slope angles, exposure, relief dispersion (standard deviation), relief trend and its local component); the density of structural and tectonic dislocations. It was established that the landslides occurrence maximum falls at altitude of 320–640 m, at slopes with steepness of 8–20°, mostly exposed to the southeast, west, northwest and south. More than 60 % of all investigated landslides occur within one kilometer zone along structural and tectonic disturbances and up to 1.2 km from disturbances with azimuth 90–180°. The applied approach made it possible to establish the patterns of landslides propagation on the bases of processing a large array of primary cartographic information and to obtain probable boundary values for the landslides formation factors characterization. Established spatial patterns of landslides occurrence can be used for local predictions of landslides hazards and implemented in provisions to be developed in order to reduce the risk of hazardous processes in Transcarpathian region.