Mapping and classification of heavy rainfall-induced hazards in the Petrich town area (SW Bulgaria)

Abstract

The torrential catchments located on the northern slopes of Belasitsa Mountain (SW Bulgaria), in the area of Petrich town were affected by an intense rainfall event in December 2021 that triggered a cascade of hazard processes like floods, landslides, debris flows/floods 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 assessment purposes, we perform field and UAV-based analysis, and mapping of the affected areas, the geomorphological changes after the flooding event, and the different types of identified mass-wasting processes. We also investigated the effects of early December 2021 heavy rain on a regional scale.