VOLUME 51 (3)/December 2022

An assessment of the landslide risk (R_ls) for the territory of Bulgaria by administrative districts has been made by combining the vulnerability (V) and landslide hazard (H_ls) maps. Landslides are a significant part of geological hazards and are widespread throughout the country. In order to assess the landslide risk for the territory of Bulgaria, it is necessary to take into account not only all landslides for a given region, but also its vulnerability, and thus to assess the level of landslide risk for this region, R_ls = f (V, H_ls). Landslide risk is determined by a risk matrix, using selected indicators and weighting coefficient of vulnerability and landslide hazard. Assessing the vulnerability of a region subjected to geological hazards is a key component of risk assessment. These include the exposure of infrastructure, industrial facilities and production capacity, residential buildings, regional GDP per capita and potential for human disability (defined by population density in the district). The data used is combined to create a map showing the vulnerability of each administrative district. Indicators of population density, GDP, length of road and railway networks and number of residential buildings were used to assess the vulnerability. The landslide hazard in each administrative district is determined by the intensity of landslide processes in the district, depending on the level of their activity and the affected area. The normalized (distributed) hazard of landslides for an administrative region is given depending on the area of the given administrative region. Landslides are categorized as active, potential and stabilized. The results express the weighted average hazard. Landslide hazard is rated from 1 to 5, where 1 means no landslide hazard and 5 means that landslide hazard has a very high intensity (very high hazard). The high degree of landslide hazard in turn leads to possible economic losses, social and environmental consequences (landslide risk). The intensity (level) of landslide vulnerability, hazard and risk is assessed as very low, low, medium, high and very high, and is shown on the relevant maps.

No abstract is available for this article.

New fossil collections from two Callovian (Middle Jurassic) localities of the South Hungarian Villány Hills (Villány, Templom Hill Quarry and Siklós, Rózsa Quarry) include specimens of the rare ammonite genus Phlycticeras and the sporadic Oecoptychius. A review is given herein on the previously published and newly found Villány specimens. Dimorphism, as well as the palaeogeographical distribution of the genera, is also briefly discussed.

This paper presents a part of the documents, which are stored in the personal archive of Professor Georgi Zlatarski at the Department of University Archive of Sofia University (Bulgaria). This valuable treasure embodies not only the development of geology in Bulgaria, but also the path of a brilliant scientist towards the realization of the plans he shared in 1880 in a letter to Prof. Konstantin Irechek: “to divide Bulgaria in separate parts and to study each one in detail”; to “make a precise geological map”, and to “arrange and systematize the collection of Bulgarian fossils”. At the end of his not very long life, it can be seen that Prof. Zlatarski succeeded in realizing his plans. In 2022, a joint project between the Faculty of Geology and Geography and the Department of University Archive, which aimed to promote the archival heritage of this eminent scientist, was carried out. With the help of geologists and paleontologists, some of the document annotations were revised to define more accurately certain documents or scientific studies. After the revision, the archive is at a higher scientific level, as it includes precise terms in geology and paleontology, making it more understandable and accessible to specialists in these fields. The chronological limits of some of the undated documents were also specified. A permanent exposition of documents on the websites of the University Archive and the Faculty of Geology and Geography, as well as a presentation on the scientific career of Prof. Zlatarski, which will be used in teaching, will soon be available.