Petar Stefanov – International Scientific and Practical Forum PROTECTED KARST TERRITORIES – LEGISLATION, TOURISM, MONITORING (ProKARSTerra`2019, http://prokarstterra.bas.bg/forum2019)

https://doi.org/10.35101/prg-2020.3.1

The forum was organized by the Experimental Laboratory of Karstology (ELK, http://www.prokarstterra.bas.bg/lab) in the National Institute of Geophysics, Geodesy and Geography of the Bulgarian Academy of Sciences (NIGGG-BAS) and was held under the motto “Protected Karst Areas – Islands of Sustainable Development”.

Peter Nojarov – CLIMATE AND ITS CHANGES IN THE PERIOD 1979–2018 IN SELECTED MODEL KARST REGIONS IN BULGARIA

https://doi.org/10.35101/prg-2020.3.2

This study reveals the climate and its changes in the period 1979–2018 in the following karst regions in Bulgaria – Devetashko Plateau, Brestnishka Karst Geosystem, Trigrad, Dabrash and Shumensko Plateau. Statistical methods are the main tool in this research. The climate of the five model karst regions is largely dependent on their location, especially on their altitude. A widespread rise in air temperatures and evaporation is observed in the months of the warm half-year. Precipitation increases mainly in September and October, and decreases in August.

Keywords: climate change, Bulgaria, karst regions, trends

Zoya Mateeva – HUMAN BIOCLIMATIC COMFORT: RISKS AND RESOURCES OF CAVE CLIMATE

https://doi.org/10.35101/prg-2020.3.3

The microclimatic conditions in the caves are very specific in comparison with the climate outside them. The extremes of outdoor climatic manifestations are difficult to reach inland cave spaces. Their microclimate is mainly determined by the temperature, humidity, air moving, and gas composition of the cave air. The transition between the external climate and that one inside the caves in most cases shows a significant degree of contrast. This places the thermo-adaptation system of the human organism under conditions of extreme strain and induces relevant thermo-physiological risks to humans. What is the extent of these risks and how they can be mitigated – this is a question of the present study that will be considered in the context of its bioclimatic parameterization. The purpose of this study is to trace how the main climatic elements in caves change compared to places outside them, what are the corresponding changes in the human heat balance and of the complex human thermal comfort, what are the risks of cave bioclimate, and what are its resources, in terms of human bio-comfort, and of human activity in cave conditions, and what actions could be taken to reduce these risks and / or adapt to them. To achieve the set multi-layered goal, the research will go through the following 4-step methodological approach: Review of the parameters of basic climatic elements in cave conditions; Parameterization of the human body heat balance and the human thermal comfort of in cave conditions; Analysis of the risks and resources of the cave microclimate in terms of human bioclimatic comfort; Identification of a package of measures for risk reduction. The obtained results show that the specific climatic conditions of the caves contain significant resources, as well as dangers in terms of the human biocomfort. It can be thermally influenced as well as by the properties of the air quality.Thermal comfort can benefit from the permanence of the cave bioclimate, but at the same time it can be at risk in the contrasting transition from outdoor conditions to those inside the caves, as well as in a longer stay with inappropriate clothing and exercise. The quality of ambient air can be beneficial for certain diseases by the presence of some mineral salts, minerals and gas particles, but at high concentrations, such as of CO2, Rn et al., it can become a danger to the human organism.To optimize the use of the cave bioclimatic resources and protect the men from the risky bioclimatic potential, the work ends with offering a set of appropriate measures.

Keywords: human bioclimatic comfort, caves’climate, cave’s bioclimatic risks and
resources, adaptation measures

Petar Stefanov, Dilyana Stefanova, Karel Turek – MICROCLIMATIC AND RADIATION CONDITIONS AND HUMAN HEALTH RISKS IN SHOW CAVES IN BULGARIA (BASED ON THE RESULTS OF INTEGRATED MONITORING)

https://doi.org/10.35101/prg-2020.3.4

There are over 6000 state-owned karst caves in Bulgaria. Some of them represent sites for mass tourism and have been turned into show-caves, which are run by NGOs or executive bodies. The paper presents the results of integrated monitoring (2010-2020) in 13 of the most popular Bulgarian show-caves, which are annually visited by over 0.6 million tourists. The applied model of integrated monitoring of cave systems (Speleo-MIKS) was developed by the Experimental Laboratory of Karstology at the National Institute of Geophysics, Geodesy and Geography – the Bulgarian Academy of Sciences (NUGGG-BAS) in international cooperation. The monitoring covers almost all indicators of the cave environment, susceptible to observations and measurements. The latter are carried out either on an expedition basis (in different months and seasons, including in extreme conditions), or on a continuous instrumental basis (including automatic stations and established monitoring networks). The monitoring covers microclimate (temperature and relative humidity, temperature of cave sediments and waters), gas composition and radiation exposure (CO2 concentration in cave air, 14C activity, Radon activity concentration, gamma radiation / gamma background); hydrochemical monitoring of cave waters; extensometric monitoring. Based on the results of the monitoring, conclusions about the condition and changes in the cave environment, as a result of tourist activity, have been drawn and summarized, while the bio-comfort and the risks for the visitors and the staff of the tourist caves have also been assessed. In 4 of the caves, CO2 concentrations of over 1% were recorded during the high tourist season (summer-autumn). In 7 of the most visited tourist caves, high average annual concentrations of Radon (from 3 to 8 kBq/m³) were also detected. Real effective doses for cave guides were calculated – in the Venetsa cave they exceeded 2.5 to 5.5 times the reference value of 6 mSv. The current state and the existing problems in the management and administration of the tourist caves have been analyzed. Two important conclusions stand out: 1. The Bulgarian legislation has not yet introduced „cave” as an existing workplace, 2. „Cave guide in a tourist cave” does not exist in the List of regulated Professions in Bulgaria. Specific measures have been proposed to optimize cave tourism. The results of the monitoring in the tourist caves also confirm the effects of global climate changes on the speleomicroclimate and the gas composition of the cave systems.

Keywords: karst, karst geosystems, tourist caves, speleomicroclimate, integrated
speleomonitoring (Speleo-MIKS), CO₂, radiation exposure, Radon-222, effective doses, gamma background, radiocarbon activity, bioclimatic comfort and bioclimatic risks.

Karel Turek, Petar Stefanov, Hana Orčíková – RADON (RN-222) CONCENTRATION IN SAEVA DUPKA CAVE AND ESTIMATION OF EFFECTIVE DOSES FOR GUIDES

https://doi.org/10.35101/prg-2020.3.5

More than 8 years of radon (Rn-222) monitoring was carried out to cover a seasonal variability in Saeva dupka cave. Radon can serve as tracer for cave microclimate, air ventilation and circulation studies. Radon monitoring is also important due to the issue of personnel radiation safety of guides and cavers. Track etch detectors placed inside plastic chambers were used for the radon activity concentration determination. Chambers were located at several measuring points inside the cave, exposure times varied among 1 week and 3 to 5 months. Long term courses of radon activity concentration show periodical trend with the remarkable peak in the turn of summer and autumn every year. Seasonal maximum and average values of radon concentration were calculated and used for estimation of the effective doses to guides related to the real time spent inside the cave. The obtained values of doses are close to the reference level for radon work places (6 mSv/year) and therefore continual radon monitoring is necessary with respect to radiation safety of guides.

Keywords: Saeva dupka cave – Rn-222 monitoring – Track etch detectors – Radon activity
concentration – Seasonal variability – Effective doses – Radiation risk

Stoyan Kyurkchiev – MICROCLIMATE IN MODEL KARST CAVES IN THE WESTERN RHODOPES

https://doi.org/10.35101/prg-2020.3.6

The cave systems have a unique cave climate for each of them. This is due to the structural complexity and individuality of separate karst geosystem. At this stage there is no generalized model of the speleoclimate, but there are some regularities in the distribution, dynamics and seasonality of the speleoclimatic parameters: small annual temperature amplitude, high humidity, seasonal change in the direction of air circulation, specific gas composition. The dynamics and circulation modes of the speleoatmosphere are determined by the morphology of the cave system and climatic conditions (the difference in air density caused by differences in temperature and pressure on the surface and in the cave, system determine the changes of the ventilation regimes of the cave atmosphere). The seasonal change in the direction and intensity of the ventilation regimes in the karst caves is a leading factor determining the gas composition of the speleoatmosphere during the different seasons. The average annual temperatures in the explored caves fluctuate in a wide rage – from 6,6°C for Ivanova Voda cave, to 11,5°C for Stara cave. In the caves where rivers flow, it has been established specific temperature regimes to each of them and the relative humidity of the cave air. Based on the measured temperatures in the investigated caves, the microclimatic zones in them has been determined. There are three zones in the caves under study, and in some of them are located and subzones formed by the influence of the morphology of the cave. The results of the microclimatic monitoring in the investigated caves are used to clarify the influence of their ventilation regimes on the volumetric activity of the radon. The purpose of this study is to investigate the microclimate of selected model caves with different morphology and temperature regimes in the Western Rhodopes.

Keywords: karst, karst caves, ventilation, speleoatmosphere, speloclimate, monitoring

Еmil Botev, Valentina Protopopova, Iliana Popova, Petar Stefanov – SEISMIC MONITORING IN BULGARIA AND SOME INTERCONNECTIONS

https://doi.org/10.35101/prg-2020.3.7

Expert generalized analysis of the distributions of 2557 earthquakes that occurred during 2017-2019 in Bulgaria, sector outlined by latitude j =41°–44.5°N and longitude l=22°–29°E, is presented. Analysis of the seismicity on the basis of the epicentral map of the earthquakes with magnitude M>2.0 on the territory of Bulgaria and its very adjacent lands is proposed. Some interconnections of the seismicity with the measurements of fault micro displacements and radon concentration in some Bulgarian caves are discussed. The observed microextensions and radon emissions in the caves and their connection with the seismicity are not completely enough, at the current stage of research, to talk about earthquake forecasting.

Keywords: Bulgaria, seismicity, seismic monitoring, fault micro displacement and ²²²Rn concentration in caves

Ekaterina Shilegarska, Tsvetelina Toleva, Petko Petkov, Albena Pophristova – KARST MONITORING AT ZLATNA PANEGA QUARRY

https://doi.org/10.35101/prg-2020.3.8

The karst region of Zlatna Panega village has been interesting for many years with regards to extraction of the main carbonate rocks that are used as a material for cement manufacturing. The impact of quarry on the karst environment and particularly on the groundwater system in term of quality and quantity is of particular importance to “Zlatna Panega Cement” AD and therefore the company takes this into consideration when it develops its mining program and when it introduces specific monitoring activities aiming at protection of karst phenomenon as well as at preservation of unique karst ecosystems. The company has based its quarry operations and nature preservation activities on scientific studies and monitoring results of many years and it is looking further to develop the quarry with a positive ecological impact. For this reason, “Zlatna Panega Cement” AD conducts yearly seismic measurements, monitoring of underground water and monitoring of the flora and fauna in the area of the quarry.

Keywords: karst, underground water, monitoring, seismic measurements, quarry, biodiversity

Dilyana Stefanova, Petar Stefanov, Georgi Jelev – CHANGES IN LAND COVERAGE AND LAND USE IN SELECTED MODEL KARST AREAS OF BULGARIA

https://doi.org/10.35101/prg-2020.3.9

Karst geosystems are characterized by high vulnerability and increased risk of impacts, especially against the background of growing global change. Bilateral direct and indirect connections are established between human activities and karst processes and the ongoing intensive changes in land use in karst territories are an active factor in modern karstogenesis. On the other hand, the changed and disturbed karst environment leads to serious environmental damage, which, due to the specifics of karst geosystems, may remain poorly visible, but with lasting and increasing effects over time, especially on soil and vegetation cover and the quantity and quality of underground karst water. Therefore, studies based on land cover and land use play an important role in optimizing land management in karst areas and in developing policies for strategic development of karst areas. This article examines the impact of land cover and land use change on different types of karst in Bulgaria. For this purpose, five karst regions were selected, based on representative model karst geosystems: Model area1 (MA1) “Brestnitsa”, MA2 “Devetashko plateau”, MA3 “Shumensko plateau”, MA4 “Dabrash” and MA5 “Buynovsko-Mursalishki”. A GIS database (KARST.gdb) with a set of vector and raster layers has been created for each region. The change of the land cover was traced on the basis of the data from CORINE land cover for the period 1990-2018. Each region is presented with brief descriptions of the karst, the administrative-territorial location and the nature protection status under the Protected Areas Act (PAA) and NATURA 2000. The changes of the land cover at level 1 of CORINE are analyzed, represented mainly by two classes – agricultural lands and forests and semi-natural areas. The use of level 3 gives more details in order to take into account potential negative impacts on the karst territories in the different model areas. The changes for four periods are analyzed: 1990-2000, 2000-2006, 2006-2012, 2012-2018. The large data set makes it possible to trace how the land cover has changed over the last 30 years in the selected model karst areas. Emphasis is placed on changes in CORINE land cover in the class of agricultural lands and the class of forests and semi-natural areas. Each model area, according to its specifics, has predominance of one or another class of land cover, which has a changing in time effect on the karst. Due to the overlap in the regions with developed karst of the karst and socio-economic systems and the interconnections and relationships created between them, a number of negative effects and transformations are manifested. This requires good knowledge and monitoring of karst geosystems, including changes in land cover and land use. Information about these changes is an important additional data source for the current state of specific and highly vulnerable karst areas. Therefore, the CORINE information can also be considered as part of integrated monitoring of the karst and karst areas.

Keywords: karst, karst areas, land cover, land use, CLC

Aleksandra Ravnachka – TRENDS IN THE DEMOGRAPHIC DEVELOPMENT OF THE DABRASH KARST AREA OF THE WESTERN RHODOPES

https://doi.org/10.35101/prg-2020.3.10

The main purpose of the study is to reveal the current state and trends in the demographic development of the Dabrash karst area. The karst in the study area has a limited spatial distribution, but despite this fact, it is extremely diverse. The population with its number, demographic and social characteristics, its economic activity, indirectly influences the evolution of the karst. The current ongoing processes of depopulation, aging and migratory mobility of the population have been analyzed in the paper. The demographic and social characteristics of the population have been studied through calculation of indicators which describe the
demographic structures, thus allowing the disclosure of a number of features that determine both the current state and the future development trends of the local population. The negative demographic processes occurring in the Dabrash karst area, are less manifested in comparison to Blagoevgrad district and the country as a whole. The most significant demographic problems in the area are the declining birth rates, the reduction of the number of young and working-age population, the emigration and the low level of education of the local population. These processes will have an increasing negative impact in the future, both on the demographic
situation and on the overall sustainable development of the area.

Keywords: Dabrash karst area, demographic development, depopulation, aging, educational
and age structure of the population

Dorota Okoń, Ewa Żurowska – Oleś – PROBLEMS OF PROTECTION AND ACCESS TO KARST AREAS IN POLAND ON THE EXAMPLE OF THE EAGLES’ NESTS LANDSCAPE PARK (KRAKÓW-CZĘSTOCHOWA UPLAND)

https://doi.org/10.35101/prg-2020.3.11

In the article, the authors present selected examples of protection and access to karst areas, mostly on examples from the Silesian Voivodeship, the area of which is administered by the authority of the Complex of Landscape Parks of the Silesian Voivodeship (CLPSV).
The Eagles’ Nests Landscape Park (ENLP) is one of the oldest landscape parks in Poland. The diverse natural, landscape and cultural of environment of the karst area of the Krakow – Częstochowa Upland is protected in this landscape park. In the article the authors will
focus on the main internal and external threats to the karst area on the example of ENLP and the methods of their elimination. ENLP has a planning document, a protection plan, which introduces the division of the park area into areas and sub-divisions for protection activities, functional zones and sub-zones. A total of 6 areas with varying degrees of protection and access were determined. Various activities are carried out to protect one of the main karst areas in Poland. In addition to conservation nature protection specified in planning documents, an important element of this protection are activities of active nature protection, as well as preventive,
promotional and educational activities. Cooperation between various institutions in Poland and with representatives of other institutions dealing with the protection of karst areas in Europe is also important.

Keywords: karst areas, landscape park, protection plan, active nature protection activities, education, promotion of the protection areas, the Kraków-Częstochowa Upland, The Eagles’ Nests Landscape Park