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Applicability of Control Region of Mitochondrial DNA for Assessment of Turbot Populations Along the Bulgarian Black Sea Coast

Author(s): Petya Ivanova,Nina Dzhembekova,Ivan Atanassov,Krasimir Rusanov,Violin Raykov,Ivelina Zlateva,Maria Yankova / Language(s): English Publication Year: 0

Turbot is a valuable commercial fish species classified as endangered. Knowledge of the level and distribution of genetic diversity in turbot is important for designing conservation strategies for their sustainable survival and to preserve their evolutionary potential. Mitochondrial control region sequences were investigated to evaluate variability in population genetic structure of one population along the northern Black Sea coast. 19 CR haplotypes were found in the Shabla population, which were shared with turbot haplotypes, previously described for the Black Sea and the Mediterranean. A pattern with a high level of haplotype diversity (h = 0.954 ± 0.022) and a very low level of nucleotide diversity (π = 0.00563 ± 0.00063) indicated a high number of closely related haplotypes and suggested that this population may have undergone a recent expansion. Tajima’s D test and Fu’s FS test both suggest recent population growth. The haplotypes found in the Shablа population were typical for the north Black Sea populations and could be used for distinguishing the population along the Bulgarian Black Sea coast.

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Open Source GIS Decision Support Tools for Wildfire and Flood Natural Hazards with Embedded Interactive Training Resources

Author(s): Stefan Stefanov,Nina Dobrinkova,Emilia Tosheva / Language(s): English Publication Year: 0

Training of volunteers that participate in natural hazard suppression measures is very important and time consuming. The volunteers do not have unlimited amount of time to dedicate on educational activities. Thus, interactive training platforms are the next step of the training processes. In our paper we will describe an open source Geographic Information System (GIS) tool specifically designed to support decision making for field operations in cases of natural disasters. The training activities for the tool implementation were based on Google G-Suite cloud application. The GIS application was developed to deliver field situation alerts in operational room and G suite was used before the field work as preparatory training for the teams working with it. The combination of the online tools described in the paper is presented as potential first step of real time volunteer training system that in future can be further elaborated and improved.

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Methodology for Calculating the Parameters of Radio Paths with Ionospheric Reflection

Author(s): Plamen Mukhtarov,Rumiana Bojilova / Language(s): English Publication Year: 0

A methodology for calculating the parameters of radio paths operating with ionospheric reflection that depends on the state of the ionosphere and at a given distance of radio communication is presented. Based on the critical frequencies of the ionospheric regions E (foE) and F (foF2) and the maximum usable frequency at a distance of 3000 km (MUF3000), the electron density profile is reconstructed and the geometry of the radio wave reflection from the ionosphere is determined. As a result of the modeling, the frequency range of the radio waves at which radio communication is possible is determined; the latter is limited by the lowest usable frequency (LUF) and the highest usable frequency (MUF) illustrated by an example.

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GIS in Crises Management Use of Smart Phone GIS Application in the Event of Natural Disaster

Author(s): Aleksandar Petrovski,Nenad Taneski,Jugoslav Ackoski / Language(s): English Publication Year: 0

Today it has become both the government and citizens concern to care human beings against ever-increasing crisis around the globe. There are so many natural disasters like: forest fire incidents, earthquakes, floods, eruptions, tsunami and etc. despite all this kinds of natural and man- made disasters from a social perspective, it their potentiality to seriously and irreversible damage regions. In addition the extent and severity of such incidents may significantly affect the population. For that reason and the fact that Geographic information system is recognized as a useful system for alleviation the risk during the crisis management we develop the idea to promote a new model to have a practical and applicable method of GIS adoption within the crisis management in order to save as many lives as it can be done. This study aims to come out with a model that will not allow drop links. Each smart phone will have application in the event of natural disaster and it switched due to the change of the vital function of man in trouble. This will help departments respond as soon as they can and save lives as many as they can and to reduce the percentage of people who could not call for help. This work highlights the design challenges and required technical innovations towards the goal of making GIS much more useful.

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Framework for Wildfire Danger Prediction System

Author(s): Nina Dobrinkova,Maria Asenova / Language(s): English Publication Year: 0

Wildland fires are natural hazard that occur every year in different parts of the world. European Mediterranean countries often are suffering from this disaster and in some cases human casualties plus infrastructure damages are in place. Bulgaria as part of the north east Mediterranean basin is affected by wildland fires in the last three decades more often than before. In our article we will present a framework for wildfire danger prediction system by usage of wireless sensor networks collecting real data and elaborating it into alerts. The test area is located on the territory of South-West state-owned forestry district. The described approach is based on the national fire danger rating algorithm, but in our case downscaled to daily prognosis. The system is under construction at the time of the paper writing thus the framework of the system main functionalities is the main scope of the article.

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Evaluation of Sentinel-3a OLCI Ocean Color Products in the Western Black Sea

Author(s): Violeta Slabakova,Natalyia Slabakova,Snejana Moncheva,Nina Dzhembekova / Language(s): English Publication Year: 0

Ocean color remote sensing has entered a new era with the successful launch of the Ocean and Land Colour Instrument (OLCI) on board Copernicus Sentinel-3 satellites. The representativeness and accuracy of the OLCI geophysical products are poorly quantified in the Black Sea which is featured by high bio-optical complexity. This paper addresses the evaluation of the OLCI/3A sensor's performance for retrieving ocean color products of the western Black Sea waters, by carrying out qualitative and quantitative match-up analysis between in situ and OLCI data. Results indicate a systematic underestimate of the water-leaving radiances (more pronounced at 412 and 665 nm) in contrary to the OLCI standard Chlorophyll (CHL) products which significantly overestimate the in situ records. These findings confirm the need of consistent reference in situ bio-optical data with improved spatial and temporal coverage for further satellite ocean color missions calibration and validation activities in the Black Sea.

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A Modelling System for Numerical Weather Prediction in the Bulgarian Antarctic Base Area

Author(s): Boriana Chtirkova,Elisaveta Peneva,Gergana Georgieva / Language(s): English Publication Year: 0

The weather forecast of good quality is essential for the humans living and operating in the Bulgarian Antarctic Base (BAB), located on the Livingstone Island coast at 62.64⁰ S and 60.36⁰ W. The numerical weather prediction models in southern high latitude regions still need improvement as the user community is limited, little test cases are documented and validation data are scarce. The modelling system is based on the WRF model, configured in three nested domains down to 1 km horizontal resolution, centered over BAB. The main objective of the study is to configure and validate the WRF model and to recommend certain set-up parameters like model area coverage, topography, land use, vertical levels, physics parametrization schemes, preparation of initial and boundary conditions and run configuration on HPC machines. Three test periods of “bad” weather events are considered during the summer seasons in 2016, 2017 and 2020. The ability of the 3 days forecast to capture the basic meteorological events in this period is discussed. Sensitivity experiments to the land use type are conducted and while the MODIS land data is found to be the most accurate for the region, a slight increase in the soil thermal capacity results in better model performance.

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The Western Black Sea Waves 1980-2020 – Study Based on ERA5

Author(s): Vasko Galabov / Language(s): English Publication Year: 0

The study presents a reconstruction of the Western Black Sea wave climate based on a numerical hindcast using the SWAN wave model and ERA5 input data. While there are many wave hindcasts reconstructing the Black Sea wave climate, based on various atmospheric reanalysis projects, the present work is the first based on the state of art ERA5 reanalysis. We focus on the storminess affecting the Bulgarian coast. The storminess in the recent decade (2010-2019) was found to be the highest compared to the previous 3 decades covered by the reanalysis (while the previous 2000-2009 is with the lowest), but the trends in the storm proxies used in the study are not statistically significant. This confirms the conclusions of other studies that the wave climate of the Western Black Sea is steady.

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Seismicity Patterns Associated with Earthquakes on the Balkan Peninsula

Author(s): Emil Oynakov,Dimcho Solakov,Irena Aleksandrova,Jordan Milkov / Language(s): English Publication Year: 0

Statistical analysis was performed, which revealed statistical parameters of the seismic setting before the earthquake in the region of Crete (01.04.2011 with coordinates 26.56oE, 35.64oN; Ml = 6.2, h = 63 km and T0 = 13: 29: 10.5 ). For this purpose, the spatial and temporal changes in the b-value and the value of the Z-seismic lull were estimated. The temporary change in the b-value shows that the average value of b decreased from 1.75 ± 0.02 between 1985 and 2002 to 1.4 ± 0.02 between 2003 and 2011. A significant decrease in the b-value and clear anomalies of calm in the Z-value in early 2011 were also observed in several neighboring areas. The epicenter of the earthquake falls in an area with a relatively low value of the a-parameter estimated for the entire previous period. In the study area, the abnormal decreasing trend of the b-value may be an indicator of increased stress, and the increasing trend of the Z-value may indicate areas of calm before the studied earthquake.

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Parameters of the Seismic Risk for Blagoevgrad Region, Bulgaria

Author(s): Petya Trifonova,Dimcho Solakov,Stela Simeonova,Metodi Metodiev,Stefan Florin Balan / Language(s): English Publication Year: 0

The present study investigates the characteristics of seismic sites of some of the NOTSSI monitoring network stations, based on microseismic noise. Nakamura's method of the spectral ratio of the horizontal to the vertical components of the seismic noise (H / V), directly related to the S-wave velocity of distribution (Vs) at the observed site was used for calculating the station repairs. The spectral H / V ratio of the seismic noise for 11 seismic stations is calculated, combined with geological data bellow each station. The values of A0 - site-effect, f0 - resonance frequency and h - depth of reference at the most contrasting resonance boundary were obtained. Attention is paid to seismic instruments and sensors

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Geoarchaeological Research in the Area of the Cape Shabla Using Unmanned Aerial Vehicles, North Bulgarian Black Sea Coast

Author(s): Bogdan Prodanov,Preslav Peev / Language(s): English Publication Year: 0

This paper aims to set out the role of using aerial remote sensing and marine hazard can play in informing responses to global challenges of coastal cultural heritage and enhancing the sustainable development of coastal zones. Aerial remote sensing and photogrammetric approaches are an integral part of modern archaeological research. In the last two decades of the century, a significant change in approaches to archaeological research has taken place: from direct fieldwork and excavation to remote sensing. In Bulgaria, this scientific discipline is quite new and it is in its infancy. However, during the last few years, the Institute of Oceanology – BAS conducted such types of investigations and a lot of new data have been collected. For this initial survey has been chosen a heritage site on the Bulgarian seashore. The studied area is the archaeological site Caron Limen/Caria at the Cape Shabla and it is determined as highly hazardous to coastal erosion. A systematic archaeological study of the topographic evolution of the coast in association with the functionality of case study area and other coastal facilities during Late Antiquity and Medieval Ages provides new data on the development of coastal life and especially the nature of sea exploitation in the context of maritime commerce.

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Earthquake Scenarios for the City of Ruse

Author(s): Dimcho Solakov,Stela Simeonova,Plamena Raykova,Boyko Rangelov,Constantin Ionescu / Language(s): English Publication Year: 0

Earthquakes are the deadliest natural disasters affecting the human environment. Global seismic risk and vulnerability to earthquakes are increasing steadily as urbanization and development occupy more areas that a prone to effects of strong earthquakes. Furthermore, uncontrolled growth of mega cities in highly seismic areas in the world is often associated with the construction of buildings and infrastructure, inconsistent with the regional seismo-tectonic features and seismic hazard. The assessment of seismic hazard and generation of earthquake scenarios is the first link in the prevention chain and the first step in the evaluation of the seismic risk.In the present study a deterministic earthquake scenario (expressed in macroseismic intensity MSK) for the city of Ruse is generated. The study is guided by the perception that usable and realistic, based on both local seismic history and tectonic conditions, ground motion maps have to be produced for urban areas. The scenario maps account soil amplification effects using the geotechnical zonation of the considered urban area.

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Complex Assessment of the Urban Earthquake Risk

Author(s): Dimitar Stefanov / Language(s): English Publication Year: 0

The impact of earthquakes in urban areas is a complex problem compounded by multi-hazard and consequential risk issues, enormous inventory of vulnerable physical elements and the attendant socio-economic problems. An approach for assessment of urban earthquake risk is presented. Rational urban risk predictions and expected losses from major earthquakes in the future serve the basis and also provide strong reasons for the pro-active risk mitigation activities. The proposed approach is based on a combination of numerical values for the determined levels of consequences in the three considered areas (social consequences, material consequences, economic losses).

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Assessment of Landslide Susceptibility and Hazard along the Northern Bulgarian Black Sea Coast

Author(s): Plamen Ivanov,Vladislav Zaalishvili,Rosen Nankin / Language(s): English Publication Year: 0

The Black Sea coast is one of the regions of Bulgaria with distribution of a significant part of the Bulgarian landslides. The analysis of the factors influencing the stability of the coastal slopes shows that they have a higher concentration and more intensive total impact on the northern part of the Bulgarian Black Sea coast, where most of the larger landslides are located. In this study, the Mora and Vahrson method was applied to estimate the landslide susceptibility along the northern Bulgarian Black Sea coast. This method is based on evaluation of various local factors for slope instability which are estimated using a Geographic Information System. The purpose of the study is to produce a landslide susceptibility map and to locate landslide-prone areas for this region.

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Assessment of Empirical Relationships between Beach-Face Slope and Sediment Size Using Field Data (Burgas Bay Case)

Author(s): Petya Eftimova,Nikolay Valchev,Bogdan Prodanov,Nataliya Andreeva,Todor Lambev,Liubomir Dimitrov / Language(s): English Publication Year: 0

The study examines the relationships between the beach-face slopes and sediment sizes for several coastal stretches located in Burgas Bay using limited field data, and explores the applicability of a number of previously developed formulations for local geomorphic, lithologic and wave conditions. Knowledge on the clear dependence between considered parameters is of particular importance for many engineering applications such as calculation of maximum run-up, shoreline changes, beach berm erosion potential, and assessment of coastal flood and erosion hazards. The results have shown that none of the considered empirical relationships can be used straightforwardly, although some of them might be considered for future analysis. Hence, it is necessary to enrich the database with wider ranges of beach-face slopes, sediment sizes coming from areas with different wave exposure and morphodynamics state in order to elaborate a reliable native relationship suitable for local to regional specifics of the western Black Sea coast. This underpins the importance of regular coastal monitoring.

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An Earthquake Catalogue for Bulgaria and Adjacent Areas since 1981

Author(s): Dimcho Solakov,Stela Simeonova,Plamena Raykova,Irena Aleksandrova / Language(s): English Publication Year: 0

A homogeneous earthquake catalogue for Bulgaria and adjacent areas covering the period 1981–2019 is presented. The existing catalogues (including instrumental seismicity) for Bulgaria, covering the time period 1981–2000, were updated for the time period 2001-2019 using instrumentally determined focal earthquake parameters. In the present update catalogue, MW is calculated for the entire period 1981–2019 applying the regression equations converting magnitude scales used in Bulgarian seismological routine practice (Md and MP) to the most reliable and widely used scale of magnitude, i.e. the seismic moment magnitude, MW. Thus, a magnitude homogeneous catalogue concerning MW scales is presented. The extended catalogue contains 645 independent events. The completeness test revealed that the catalogue is complete for moment magnitudes larger than or equal to 3.2 for the last 39 yr.

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Aggregated Tsunami Scenario for Karpathos Island

Author(s): Lyuba Dimova,Reneta Raykova,Alberto Armigliato,Gianluca Pagnoni,Stefano Tinti / Language(s): English Publication Year: 0

Karpathos is the second largest of the Greek Dodecanese islands. Historical data such as the event of 9 February 1948, indicate that this area is prone to earthquakes and tsunamis. In this study we evaluate the tsunami hazard for the Karpathos Island by means of a scenario-based technique. We take into account tsunamis generated by three main seismic sources in agreement with local tectonics and historical records. The code UBO-TSUFD is used for all numerical simulations. Tsunamis are computed in several domains with different resolution for a better calculation of the maximum coastal wave height and tsunami inundation. Tsunami parameters for each individual scenario are used to construct a unique aggregated scenario, which help us to evaluate the inundation zone. The contribution of all scenarios along the coast of Karpathos is studied via synthetic mareograms. It is found that EHA dominates and that the southern Karpathos is more exposed to tsunamis.

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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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Initial Assessment of Composition, Abundance, Spatial Distribution and Hotspots Identification of Floating Macro-Litter in the Bulgarian Black Sea Waters

Author(s): Violeta Slabakova,Ivelina Zlateva,Krasimira Slavova / Language(s): English Publication Year: 0

The present research is focused on composition, density, distribution and identification of accumulative areas of floating marine litter (FML) in the Bulgarian Black Sea coastal, shelf and offshore waters. Macro-debris abundances were determined in compliance with MSFD protocol for visual observations based on fixed-width strip transect method. Six floating litter monitoring surveys were carried out between 2017 and 2019. Over 144 hours of visual observations were performed in a total of 288 transects, covering an overall survey area of 7.52 km2. 1320 litter items were identified and classified during the campaigns of which 90% were detected as plastic materials. The presence of floating debris was observed throughout the entire study area with density ranging from 0 to 1750 items km-2 and average density of 170 items km-2. Unexpectedly marine litter concentration patterns were evenly distributed among the studied regions with some specifics at certain sites.

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Endemic Forests in Danger: Land Use Shifts and Accompanying Impacts upon the Natural Flood Storage Reservoirs along the North Bulgarian Black Sea Coast

Author(s): Iliyan Kotsev,Bogdan Prodanov / Language(s): English Publication Year: 0

Longozes represent endemic forests native to the East Balkans. Key factors for their existence are the humid subtropical climate with mild winters and the river inundations occurring twice-yearly. These hygrophilous forests play an essential regulatory role in the runoff peaks by ensuring a crucial ecosystem service as flood storage reservoirs. Nowadays, because of highly decreased and fragmented areals, longozes are red-listed as critically endangered. Hence, they are subject to preservation in compliance with the EU Habitats Directive and Annex 1 of Bulgaria’s Biodiversity Act. Aim and objectives of the study herein are: to investigate the spatio-temporal changes in the longoz forests’ areals along the North Bulgarian coast; to analyze the consequences of the anthropogenic impacts upon the river runoff; to provide a generalized assessment of the longozes’ contemporary flood retention capabilities. Topographic maps from the late 19th century were integrated in GIS to reconstruct the longozes’ historical extents by on-screen digitizing of the areas of interest. Analogous procedures were applied to such from the mid-1970s, a time frame correlating with the Socialist extensive development of Bulgaria’s coast. The areas’ historical land cover as in the late 1980s was further refined using Landsat imagery. These historic data sets were chronologically compared to the longozes’ contemporary extents, available as up-to-date cadastral data. The comparisons were executed using GIS crosstabulation techniques. The analyses demonstrate the ubiquitous decrease of the longozes due to overexploitation of the wood resources, land use shifts, resort construction, decreased river runoff, etc. These findings imply for a deteriorated environmental status, impaired flood storage capacity and the inability of the woods to act as a regulator of the peak ourflows nowadays, well correlating with the recent extreme coastal floods with fluvial origin.

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