ANALYSIS OF SPATIAL PATTERNS OF LANDSLIDE FORMATION WITH GIS TOOLS (ZAKARPATSKA OBLAST)

Abstract

To identify the primary and derived geological factors determining the spread and activation of landslides within Zakarpatska Oblast, a database of 2.575 landslides were collected and integrated into GIS, with a total area of 385.21 km2 covered. Using the ArcView Spatial Analyst environment, the factors of landslide formation represented by the constructed grids of the relief, its derivatives, and the density of structural-tectonic heterogeneities have been examined. It has been established that landslide development maximum occurs at heights with hypsometric marks of 280–730 m, slopes of 7.5–22.4° steepness, oriented to the west, south-west, south, and south-east and located at a distance of up to 500 m from watercourses. Two-thirds of all analyzed landslides are located within a kilometer zone along structural-tectonic disturbances and at a distance of up to 1250 m to disorders with the 90–180° azimuth. The approach applied made it possible to establish for the first time ever the patterns of landslide occurrence, relying on the results of processing a large array of primary cartographic information, and to obtain probable limit values characterizing landslide formation factors, as well as build an iterative regional predictive model for forecasting landslide hazards occurrence. Mapping of areas with characteristic values of the factors determined will be used for local landslide forecasts. It will be implemented in the development of measures to reduce the risk of hazardous landslide processes in Zakarpatska Oblast.