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Statistical Assessment of Annual Maximum Daily Precipitation over Bulgaria in the Period 1892-2018

Author(s): Krastina Malcheva,Tania Marinova,Lilia Bocheva / Language(s): English Publication Year: 0

Annual maximum daily precipitation from 292 meteorological stations of the national meteorological network has been used to investigate the statistical properties of extreme precipitation in the period 1892-2018. The stationarity of time series has been examined for abrupt changes and slow variations by the non-parametric Pettitt and Mann-Kendall tests. The return levels of annual maximum daily precipitation for selected probabilities of exceedance have been assessed on the base of the best-fitted combination of probability distributions and parameters estimation methods for each of the time series.

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Effect of Saharan Dust Intrusions on Precipitation Chemistry in Bulgaria

Author(s): Emilia Georgieva,Elena Hristova,Blagorodka Veleva / Language(s): English Publication Year: 0

The objective of this work is to investigate the influence of Saharan dust events on the chemical composition of rain samples collected at three sites in Bulgaria during 2017-2018. Saharan dust intrusions were identified through a combination of satellite retrieved aerosol data and results from dust forecasting models and from backward trajectory model. The chemical composition of the samples (acidity pH, conductivity EC, main ions and elements) is analysed in view of the direction of the approaching air masses – “direct” influence (south-west), and “indirect” influence from other directions and regions, already impacted by Saharan dust. All samples were characterised by elevated values of pH (max 7.4), EC (max 202 µS.cm-1) and Si, Ca, Fe, Mg concentrations. For cases with direct influence Si and Ca values were up to 1.5 and 25 mg.l-1. In most of the indirect cases increased concentrations of sulphate, nitrate and ammonium were observed (up to 39.5, 23.1 and 8.3 mg.l-1)

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PBL Vertical Structure During Extreme Wind Events at Seaside Region of Southern Bulgaria

Author(s): Damyan Barantiev,Ekaterina Batchvarova,Hristina Kirova,Orlin Gueorguiev / Language(s): English Publication Year: 0

round-based remote sensing (GBRS) data collection with Scintec Sodar MFAS was performed in southern Bulgarian Black Sea side from August 2008 until October 2016. These high spatial (10 m) and temporal (10 minutes with averaging time of 20 minutes) resolution measurements of wind and turbulent parameters have been used to explore the vertical structure of the coastal boundary layer during extreme wind events. For this purpose, the ninety-percentile of the two-parameter Weibull distribution of the wind speed at every sodar measurement level from 30 up to 600 m is used as a criterion to define the “rare” values within their statistical distributions and to identify a theoretical extreme wind speed profile (reference profile). On this basis, the extreme profiles during the reviewed period have been determined and their multiple time series have been then used to derive averaged profiles of twelve sodar output parameters under extreme winds conditions.

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Black Sea Holocene Environmental Setting in Respect of Ostrea Edulis Appearance and Loss

Author(s): Ivan Genov,Krasimira Slavova,Tzvetana Nonova,Elena Koleva-Rekalova / Language(s): English Publication Year: 0

Geological and palaeoclimatic Holocene setting in the Black Sea has been traced. This research suggests that the appearance of Ostrea edulis in the Black Sea during the Middle Holocene, not immediately after the invasion of Mediterranean waters, is due to the dynamics of interconnected climate and abiotic parameters of the basin. Although the reasons for the decrease in abundance of the Black Sea population of flat oysters are still uncertain, we attempts, through a comparative analysis of key abiotic factors in the past and today, to suggest that it is quite possible marine ecosystems to respond to modern changes of key climate-related drivers and pollution by changing their habitat and/or extinction. Geological approaches were used to study the abiotic factors of the environment (salinity and temperature) back in time.

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Effect of Organic Matter Loading on Nutrient and Oxygen Fluxes at the Sediment-Water Interface in Different Sedimentary Habitats in Sozopol Bay (Sw Black Sea): a Laboratory Experiment

Author(s): Stefania Klayn,Dimitar Berov,Ventzislav Karamfilov / Language(s): English Publication Year: 0

Coastal benthic sediments play an important role in regulating water column nutrient concentrations and primary production via nutrient regeneration and exchanges at the sediment-water interface. This study aimed to characterize the diffusive benthic fluxes of NH4+, NO3-, PO4-3, and O2 in some of the most common shallow sedimentary habitats (fine and coarse sands, seagrass beds, and unvegetated patches within the seagrass beds) along the Bulgarian coast, and their changes under organic loading, through a laboratory experiment. Nutrient fluxes were dominated by a release of NH4+ to the water column in all sediment types, and a parallel uptake of NO3- by the sediments; both fluxes increased under organic loading, possibly indicating stimulation of nitrate reduction within the sediments. The PO4-3 fluxes were smaller, and the sediments mostly acted as a source for phosphorus under organic loading. O2 was taken up from the overlying water in all treatments and sediment types, and this flux increased under organic loading, probably in relation to the decomposition of the organic matter and spontaneous chemical oxidation of sulphide ions, released during sulphate reduction within the sediments. The study contributes towards the understanding of nutrient cycling and the role of the benthic compartment in Black Sea coastal soft-bottom habitats.

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Assessment of the Natural Landscapes as a Prerequisite for Environmental Risk Assessment and Preparation of Management Plans

Author(s): Petja Ivanova-Radovanova / Language(s): English Publication Year: 0

he article discusses a method for assessment of the quality of the natural landscapes in one of the Nature parks in Bulgaria – Rila Monastery Nature Park – as a good practice for the evaluation of the quality of natural resources. The methodology for Rapid Landscape Assessment presented, had been initially developed for the purpose of the development of the management plan of Rila Monastery Nature Park. Significant amount of information from the field have been generated and analyzed by multi-disciplinary team in a relatively short period of time. It was proved that the approach of rapid assessment is a good practice for cost-effective, rapid and efficient assessment of natural resources. Thus, the methodology can be used in environmental risk assessment of different sites of natural and cultural interest because such sites are normally not only underestimated and also under pressure from different kinds of developments and time constrains.

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Seismicity on the Territory of Bulgaria and Surroundings Recorded by NOTSSI for the Period 2017-2019

Author(s): Dragomir Dragomirov,Emil Oynakov,Valentin Buchakchiev,Jordan Milkov / Language(s): English Publication Year: 0

A map of epicenters of 411 earthquakes with magnitude Mw >= 2.5 that occurred from 2017 to 2019 in Bulgaria and surroundings (sector outlined by latitude = 41o- 44.5o N and longitude = 22o- 29o E) registered by NOTSSI is presented. Analysis is done on the distribution of the events through time and space, magnitude and depth. The events frequency progression is analyzed for the whole studied period and then compared with each year separately. Generalized analysis is proposed as to what can contribute to variations in the data for the studied period. Catalog of earthquakes with magnitude Mw >= 3.5 is applied.

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Intrinsic Oscillations of River Stream Flows Determined by ARIST Method

Author(s): Yavor Chapanov / Language(s): English Publication Year: 0

The river streamflows analyses can be successfully used in water resource planning and management, depending on the needs of the wide range users. It is possible to use these applications in several general directions: as informal, qualitative guidance for water managers, stakeholders and decision makers and prediction about long-term drought variability; for quantitative assessments of long-term hydrologic variability and assessment the severity and duration of drought cycles; as direct inputs into hydrologic models of a water system, etc. The long-term oscillations of the river streamflows are influenced mainly by the solar activity and climate interaction, whose variations often consist of synchronous cycles. The intrinsic oscillations of Danube and Don streamflows are determined by the recently created autoregressive method ARIST. These oscillations are compared with the intrinsic oscillations of solar and climate indices and mean Black Sea level variations. Conclusions about the use of intrinsic oscillations in floods or drought prediction are made.

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Ecological Assessment of Struma River in Pernik Region, Bulgaria in December 2019

Author(s): Antonina Kovacheva,Diana Rabadjieva,Radost Ilieva,Rumiana Gergulova,Veselin Nanev,Ivelin Vladov / Language(s): English Publication Year: 0

The hydrological characteristics of water basins in Pernik region, Bulgaria have been badly worsened since the summer of 2019. This study was performed in the low-flow period of December 2019 and covered eight sampling stations along the Struma River between Studena dam and Pchelina dam, region of the town of Pernik. The analytical data obtained and the calculated threshold pollution indices of the single nutrients PO43-, NO2-, NO3- and NH4+ and their integrated threshold pollution indices showed water pollution in respect of PO43- and NH4+. The concentrations of PO43- at all stations, of NH4+ ions in the waters after Pernik city, and of NO3- and NO2- before Pchelina dam exceeded the respective maximum allowed concentrations (MAC) according to the Bulgarian legislation. The waters were pure in respect of the trace metals Al, Fe, Co, Ni, Cu, Zn, Cd, and Pb; only Mn exceeded its MAC. The chemical species of the trace metals were calculated by thermodynamic modeling and discussed on the base of the “Hard and Soft Acids and Bases” (HSAB) principle.

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Eco-Innovation as a Basis for Clean Production Model in the Food Industry: an Insight from Bulgaria

Author(s): Silviya Topleva,Tsvetko Prokopov,Donka Taneva / Language(s): English Publication Year: 0

n this paper we propose a model for implementation of eco-innovations of clean production in the SMEs of the food industry in Bulgaria. The clean production is a preventative approach to managing environmental aspects. The paper presents the essence of clean production, the methods for its achievement and outlining the possible options and barriers for SMEs from the food industry in Bulgaria to implement the relevant eco-innovations. The ecological footprint of the food industry makes the need for an integrated implementation of clean production practices from raw material extraction to packaging and waste disposal of final consumer.

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Assessment of the Changes in the Groundwater Recharge to Precipitation Ratio in the Recent Years Influenced by the Air Temperature and Rain Intensity Increase In The West Aegean Region Of Bulgaria

Author(s): Olga Nitcheva,Polya Dobreva,Nelly Hristova,Vesselin Koutev,Donka Shopova,Albena Vatralova,Emil Bournazki / Language(s): English Publication Year: 0

The topic of this report concerns the expected changes of the important part of the water resources of Bulgaria caused by the moving of the main precipitation to the warm seasons. The study examines the influence of the air temperature and rain intensity as main factors for the change in the potential groundwater recharge / precipitation ratio in the summer months of three recent years on the territory of Southwest Bulgaria (Basins of Struma and Mesta rivers). The assessment has been performed by application of a precipitation-runoff hydrological model, which is a sub-model of NASA's climate model.

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Rapana Venosa Rapa Whelk Responsible for Rapid Destruction of Black Sea Coastal Mytilus Galloprovincialis Littoral Reef Communities – Results from a Preliminary Study in Sw Black Sea (Sozopol Bay, Bulgaria)

Author(s): Dimitar Berov,Stefania Klayn,Ventzislav Karamfilov / Language(s): English Publication Year: 0

The dynamics of predator-prey interaction between the invasive Rapa whelk R. venosa and the black mussel M. galloprovincialis in the coastal zone of the Black Sea shapes the structure of the benthic hard rock ecosystems in the littoral area of the basin. Applying a combination of observational methods (transects, photo surveys) and exclusion ’cage’ experiments we tracked the rapid increase in Rapa whelks population density (from 1.1 ind.m2 up to 13 ind.m-2) and the destruction of infralittoral mussel communities by the Rapa whelks in the study area (from up to 2469.95±1184.82 g.m-2 wet biomass and 1054.66±228.19 ind.m-2 to practically none). A rapid recovery was noted just 6 months later in caged experimental plots where R. venosa could not reach the newly settled mussels, in contrast to open plots where no new mussel colonies developed. The importance of harvesting of Rapa whelks by divers as means of local control of their populations, and of the preservation of natural circalittoral M. galloprovincialis populations as sources of larvae for the resettlement of coastal habitats is also discussed.

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Remote Sensing of Oil Pollution in the Black Sea – the Mopang Case

Author(s): Irina Gancheva,Elisaveta Peneva / Language(s): English Publication Year: 0

This study focuses on the case of the underwater oil leak form the ship Mopang, sunk in 1921 near the city Sozopol on the Bulgarian coast. In the summer of 2018, some of its engine fuel was released and reached the coast, gaining significant public and media attention. The available Sentinel-1 radar images for the affected region for the years 2017 and 2018 are processed and the results show that oil leaks were visible as early as February 2017. Significant amount of oily discharge was detected during the summer months of both years. During the rest of the year there were occasional discharges, without accumulation during particular periods.The sunken ship Mopang is used as a verified case to demonstrate the capability of remote sensing techniques for reliable detection of oil pollution on the sea surface in small scales close to the shoreline, combining radar and optical data. Sentinel-1 and 2 images, together with drone acquisitions are analysed, discussing the benefits of each method and taking into consideration the particularities of the region of interest. Based on the availability of radar acquisitions with detected oil slicks twice a day at 4 am and 4 pm for some days, we have investigated the evolution of the detected oil slick on the sea surface, depending on the marine meteorological conditions.

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A Stochastic Numerical Approach for Contaminant Removal in Constructed Wetlands under Uncertain-But-Bounded Input Parameters

Author(s): Konstantinos Liolios,Georgios Skodras,Krasimir Georgiev,Ivan Georgiev / Language(s): English Publication Year: 0

The operation problem of Horizontal Subsurface Flow Constructed Wetlands (HSFCW) to remove pollutants under uncertainty is investigated numerically in a stochastic way. Uncertain-but-bounded input-parameters are considered as interval parameters with known upper and lower bounds. This uncertainty is treated by using the Monte Carlo method. A typical pilot case of an HSFCW concerning Biochemical Oxygen Demand (BOD) removal is presented and numerically investigated. The relevant numerical results have a good matching to available experimental ones, and so the effectiveness and the reliability of the proposed stochastic approach is proven.

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Current Migration of Bulgarians from Albania to Bulgaria: Towards a New Migration Model of the Historical Bulgarian Diaspora

Author(s): Spas Tashev / Language(s): English Publication Year: 0

The article analyzes the current status of the Bulgarian community in Albania and the ongoing migration processes towards Bulgaria. The author takes the position that Bulgaria should be open to Bulgarians in Albania in any case and at any time, but not to press them to settle in Bulgaria at any cost. The optimal solution is to promote the circular, mainly seasonal migration of Bulgarians from Albania to Bulgaria. In this way, this population will continue to live in its native places, but it may be Bulgaria’s demographic, labor and geopolitical reserve.

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Bulgarian Return Migrants: Segmentation by Accomplishment of Migration Aims

Author(s): Venelin Boshnakov / Language(s): English Publication Year: 0

The paper presents some preliminary results obtained during the realization of Research Project: “Return Migrants: Segmentation and Stratification of Economic Mobility” (2017-2020) supported by Grant No.DN05/6-14.12.2016 by Bulgarian Science Fund. These results have been derived from a dataset generated by a questionnaire survey among Bulgarian migrants conducted in 2017 after their return – temporary or permanent – to the home country. On the basis of the respondents’ statement that evaluates the achievement of their migration aims, possible interaction is explored between this achievement and the socio-economic profile of the interviewed migrants. For this purpose a binary logistic regression model has been estimated involving demographic, social, economic, and migration experience independent variables. The major results are discussed outlining further directions of a more comprehensive study of the determinants of the achievement of migration goals by return migrants.

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Stratification and Social Mobility of Bulgarian Returning Migrants

Author(s): Andrey Nonchev,Marieta Hristova / Language(s): English Publication Year: 0

The paper explores the social inequalities and mobility of returning migrants. Their social stratification is conceptualized through the concept of their socio-economic status. Different dimensions of the social stratification are examined, with the main focus on economic (income, employment, property), educational and qualification inequalities between returning migrants. The vertical (ascending and descending) economic and social mobility of the remigrants throughout the migration cycle and its individual phases is also traced. The social and economic effects of the migration carried out are analysed through the self-assessments of the return migrants’ financial and social status.

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Effects of Workers’ Remittances on the Home Country: The Case of Bulgaria

Author(s): Vesselin Mintchev / Language(s): English Publication Year: 0

The present report reviews issues, related to the compensation of employees and the workers’ remittances of emigrants. Data based on information from international institutions and from the Bulgarian National Bank, regarding the relative shares of the said pair of items in GDP, is provided. On the basis of information from an empirical sociological study, carried out in 2017 within the framework of the project entitled: “Returning Migrants: Segmentation and Stratification of Economic Mobility” (financed by the Scientific Research Fund of Bulgaria under contract No. DN 05/6 dated 14/12/2016) the profile of individuals supporting their relatives, who remained in home country, is outlined. An answer is sought to the question of what drives the active remittance behaviour of the returning migrants during their stay abroad. Indication is provided of the purposes, for which the remittances are used and the types of businesses they generate.

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Virgil Madgearu: profesorul, omul cetăţii, doctrinarul (Full eBook)

Author(s): / Language(s): Romanian Publication Year: 2020

This volume is a collective work dedicated to the memory of Virgil Madgearu (1887-1940) a preeminent professor of the Academy of Higher Commercial and Industrial Studies, the innitial name of the Bucharest University of Economic Studies. Each chapter of the book reveals defining elements of Madgearu’s life and work, his beliefs, viewpoints and active involvement in the academic and institutional development of the university (1917-1940), in the interdisciplinary research of the economy and society, in shaping the Romanian peasant doctrine and promoting Europe wide the interests of agrarian countries, in assuming political responsibilities as parlamentarian or as member of various interwar governments. As a respected professor and a leading politician he vigorously rejected the presence and influence of extreme right movements in the society and that valiant attitude was at the origin of his assassination in November 1940.

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Членството на България в ЕС: седем години по-късно

Author(s): Svetla Boneva / Language(s): Bulgarian Publication Year: 0

Bulgaria concluded its seventh year of full EU membership at the beginning of 2014. This is a period long enough to review the successes and failures, expectations, disappointments, and attempts to stand and defend our interests in the Union. The paper analyses the first seven years of the Bulgarian membership in the EU considering the challenges brought by the economic and financial crisis, growing Euroscepticism and the revival of nationalist rhetoric. The second 7-year period of the Bulgarian membership is under the multiannual financial framework between the years of 2014-2020 which significantly decreased the budget for two key EU policies – the Common Agricultural Policy (CAP) and the Cohesion Policy (CP). The author analyses the implications from the Bulgarian perspective and suggests that further efforts are needed to support country’s capacity to absorb EU funds through high-quality projects, transparency in the public procurement process and effective judiciary, public administration, more decisive steps for e-government.

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