Torrential Catchments from Belasitsa Mountain (SW Bulgaria) - Geological and Geomorphological Characteristics and Related Hazards

Abstract

AbstractFloods, debris flows, and landslides are hazardous processes that often occurred in mountainous terrains over the world and could be highly destructive. In the last few decades, these events occur more often global, causing disasters as a result of climate changes and poor hazard and risk mitigation measures in the countries. On a regional scale, the territory of Bulgaria is not an isolated case and in the last decades, there is a higher intensity of hydro-meteorological and geological hazardous events. The main object of this paper is the study of the geological and geomorphological characteristics of torrential catchments located on the northern slopes of Belasitsa Mountain (SW Bulgaria), in the area of Petrich town. The area was affected by an intense rainfall event in December 2021 that triggered hazard processes like floods, landslides, debris floods, and mudflows that caused major damage to the road network, properties, and buildings, showing the urgent need to take hazard and risk assessment and mitigation measures. For the studied area, we made a susceptibility analysis that includes a description of geological and geomorphological conditions in the area, and GIS-based morphometric analysis of the torrential catchments. For further development of hazard assessment and mitigation decisions, Melton’s ruggedness ratio was calculated in order to distinguish the sediment transport type in the catchments.KeywordsTorrential catchmentsGISMorphometric analysis