Awareness of the potential threat posed by drought necessitates the implementation of appropriate procedures to enable effective and systematic actions aimed at mitigating, or at least partially limiting, the impacts of drought events. This paper seeks to analyze the spatial and temporal changes of atmospheric drought in the period 1961–2020 and assesses drought hazards in southwest Bulgaria, which is a region susceptible to periodic water shortages. In this study, the standardized precipitation evaporation index (SPEI), accounting for both precipitation and temperature changes, was used to analyze drought characteristics. The analysis reveals significant temporal changes and spatial differences in drought patterns across southwest Bulgaria. The northeastern part of the region, including the Sofia district, exhibits the lowest risk of drought, while the central part of the region shows a tendency toward moderate and occasional low drought events. Some stations, particularly in the southern part of the region, consistently experienced more severe drought conditions (Blagoevgrad and Sandanski), as indicated by negative SPEI values in different time scales (3, 6, and 12 months). Results indicate an increased frequency of droughts during 1990–2020 compared to 1961–1990, which was driven by climate change and human activities. Across all stations and in both SPEI time scales, the period from the early to mid-1990s was characterized by significant droughts. The study of drought hazards using short-term and long-term SPEI analysis reveals different levels of drought risk and increased hazard from the northern to southern parts of the study area. The share of areas with a high drought hazard exceeds 40% of the territory in the areas with a transitional and continental-Mediterranean climate. Based on the results, the paper highlights the need to integrate drought risk assessments with regional planning to improve agricultural resilience and water resource management in response to anticipated droughts, especially in drought-prone areas such as southwest Bulgaria.

Rainfall, with its intensity, duration, and seasonal distribution, is among the main factors causing soil erosion, which is a widespread environmental problem in Bulgaria. Rainfall erosivity shows the potential of precipitation to generate erosion processes and is an essential indicator of the climate vulnerability of a region. This paper aims to evaluate rainfall erosivity in a part of the Eastern Rhodopes Mountains, an area that is characterised by high-intensity erosion processes and high erosion risk. Local peculiarities of rainfall erosivity were revealed by the calculation of some precipitation indices based on the monthly precipitation for the period 2000–2021, such as the precipitation concentration index (PCI), Angot precipitation index, Fournier index (FI), and modified Fournier index (MFI). The analysis of the extremely wet and extremely dry months at the annual and seasonal (October–March and April–September) levels was performed to evaluate the susceptibility to erosion. The results from the study show that rainfall erosivity in the studied area varies from low to moderate in the northern part of the study area and from high to very high in the south. According to the MFI, high and very high erosivities have been observed mainly since 2012. The erosivity increases from north to south, to the area with a complex relief, where the combination of orography and atmospheric circulation make favourable conditions for the occurrence of extreme precipitation. The analyses of the calculated indices show that the precipitations in most of the studied area generally have from a low to a moderate erosivity, but this does not exclude the occurrence of cases with high and very high erosivities, which are characteristic of recent years and are related to the increase in annual precipitations and extreme precipitation months. The results of this study can contribute to the development and implementation of measures and preventive activities for the reduction and possible elimination of the negative impacts of extreme precipitation.

Over the last decades, numerous extreme climate events such as extreme temperatures, droughts, heavy precipitation, and storms associated with climate change have been recorded in many countries, including Bulgaria. As a result, geomorphological hazards such as landslides, debris flows, mudflows, high-speed soil erosion, etc. often occur on the territory of the country. The debris flow is one of the most common hazardous processes in small catchments of the main river basins in Bulgaria. The Kresna Gorge located in the middle part of Struma River valley is a typical area with such processes which often cause the damages to the E79 international highway. The purpose of the present study is to characterize debris flows in Kresna Gorge (southwestern part of Bulgaria) by comparative analysis between the two events (occurred on May 24, 2009 and July 28, 2019). In order to achieve the aim of the study the geomorphological features and flow type of 2019 event were identified and the results were compared with the previous publications which investigated the event on May 24, 2009. In the present paper, the sediments and the type of transportation of the investigated event (July 2019) were determined by grain-size and clast-shape analysis. The impact of weather conditions on debris flow occurrence was shown by the analysis of the synoptic conditions on the day before the event. The results of the study bring to clarifying the geological-geomorphological and meteorological factors for the occurrence of debris flow and are important for geomorphological hazard management.

Several perennial snow and ice bodies have been recently studied and monitored in three mountain massifs across the Balkan Peninsula: Prokletije (Northern Albania), Durmitor (Montenegro) and Pirin (Bulgaria), the two glacierets in the Pirin Mountains until soon considered as southernmost of their kind in Europe. In September 2022 a relatively large snow field (about 1.5 ha) was discovered and described for a first time in the glacial cirque Gryka e Kazanit in the Nëmerçka Mountains of Southern Albania. The snow accumulation lies on 1550–1650 m a.s.l. below a vertical limestone cliff with a height of almost 1000 m. The site was visited again in November 2023, when the snow field diminished its size to less than 1 ha. At the same time, multi-annual firn layers were exposed under the last year snow, with depth at least several metres, and indications were observed of ice, buried in the debris cover below. Newest findings indicate that the studied snow-firn body is a glacieret similar to those found in the Pirin Mountains. On a longer-term, nine perennial snow/firm bodies on the Balkans resemble small glaciers rather than snow and ice patches at least under current climatic conditions. Situated on 40°08′ Northern latitude, the newly discovered Nemërçka Glacieret is nominated to be the southernmost glacier in Europe.

Precipitation in high mountain areas is of critical importance as these regions are major sources of freshwater, supporting river basins, ecosystems, and downstream communities. Changes in precipitation regimes in these regions can have cascading impacts on water availability, agriculture, hydropower, and biodiversity. The present study aims to give new information about precipitation variability in high mountain regions of Bulgaria (Musala, Botev Peak, and Cherni Vrah) and to assess the role of large-scale atmospheric circulation patterns for the occurrence of extreme precipitation months. The study period is 1937–2024, and the classification of extreme precipitation months is based on the 10th and 90th percentiles of precipitation distribution. The temporal distribution of extreme precipitation months was analyzed by comparison of two periods (1937–1980 and 1981–2024). The impact of atmospheric circulation was evaluated by correlation between the number of extreme precipitation months and indices for the North Atlantic Oscillation (NAO) and Western Mediterranean Oscillation (WeMO). Results show a statistically significant decrease in winter and spring precipitation at Musala and Cherni Vrah, and a persistent drying tendency at Cherni Vrah across all seasons. The frequency of extremely wet months in winter and autumn has sharply declined since 1981, whereas extremely dry months have become more common, particularly during the cold season. Precipitation erosivity also exhibits station-specific responses, with Musala and Cherni Vrah showing reduced monthly concentration, while Botev Peak retains pronounced warm-season erosive rainfall. Circulation analysis indicates that positive NAOI phases favor dry extremes, while positive WeMOI phases enhance wet extremes. These findings reveal a shift toward drier and more seasonally uneven conditions in Bulgaria’s alpine zone, increasing hydrological risks related to drought, water scarcity, and soil erosion. The identified shifts in precipitation seasonality and intensity offer essential guidance for forecasting hydrological risks and mitigating soil erosion in vulnerable mountain ecosystems. The study underscores the need for adaptive water-resource strategies and enhanced monitoring in high-mountain areas.