Hernani Spiridonov – Geodynamics of Bulgaria (part II)

The publication, which is Part II of the paper, considers the paleogeography and paleodynamics of the territory of Bulgaria. It is considered as part of the Moesian platform, accordingly the southernmost protruding of Lavrasia, also known as the Bulgarian plate. The latter is part of the spacious supercontinent Pangeya-2, spread- ing from one pole to the other. Its destruction started namely during this period. The Jurassic sedimentation onto this area started by continental depositions during the Hetangian and Lower Pliensbachian. They are located with clearly and abruptly marked boundary onto a motley pad with angular discordance over the Paleozoic and Triassic. Further above follow sea sediments from Upper Hetangian. Actually, they are observed to the north of the Kyustendil-Ihtiman-Stara Zagora-Elhovo line. Some 200-300 km to the south of it, the Jurassic Vardar-Izmir-Ankara subduction zone was spreading, as part of the Mesotethis Ocean. After the Callovian, the whole Southern Bulgaria started lifting up and began to supply with sediments the post-arch troughs which were forming at that time: Nish-Troyan, Svetlyano, Treklyano,Kraynene.The subduction ended in powerful abduction of ophiolite plates during Late Upper Batho- nian–Early Lower Callovian, which were a couple of kilometres thick. Today, they are observed in the Vardar zone (internal Dinaride zone) and in the Circum-Rhodo- pean sedimentation belt (innermost Helenide ophiolite belt. It continues in Turkey as the well-known Ovassik zone, which is observed from the Lesbos Island to the west to the Tokat Massif to the east in Central Turkey, also in the Rhodopes, but later mod- ified by Alpean metamorphism. The formation of the post-arch flysch troughs (Troyan, Svetlyano etc.) according to plate-tectonic postulates is caused by a kick of the subduction zone’s link in the ocean’s direction. This last event resulted in stretching in the rear of the upper plate, in our case the Moesiian plate (Lavrasia), and formation of flysch troughs on its periphery. Therefore, in them, compression accompanied by folding cannot occur. The transition from subduction regime into collision regime, which started in the end of Middle Jurassic after the ophiolites’ obduction, does not take place instantaneously, but takes millions of years whereas meanwhile, under the collision zone, the cool and thick edge of the subduction ocean plate continues existing, i.е. Intraplate subduction takes place. It lasts from Middle Jurassic till the end of Aptian (more than 50 million years) to end in the powerful Alpine thrists. Together with the subducting ocean plate, parts of the upper continenral plate are also involved in subduction and at depth greater than 20 km their metamorphism takes place. In our case, this is the Rhodopean Massif. It may be added here that, in the process of collision, in the space between the converging plates, various Tectonic elements fall in (blocks, microoceans etc.), which are united in a motley mosaic – a Tectonic collage also known as „terrains”. Obviously, the Rhodopean Massif is such a terrain, in which protolites dating since the Pre-Cambrian, the Paleozoic and the Mezosoic have been found, and later metamorphized in the interval 62-32 million years (Alpean metamorphism). The collusion regime did not take place simultaneously along the entire length of the convergence boundary, because the edge of the converging continents is geologically unhomogenous and therefore, a single linear stripe could not be formed. Actually separate indentors existed, as the currenly existing Arabic Indentor. During the Upper Jurassic–Low Cretacious collusion, two such indentors may be identified: the Tracean (Istanbul) and the Rhodopean indentor. Remnants of them are nowadays’ thrust plates. The Thracean thrust plate has been known for a long time today under different names: Strandzha thrusts, East-Rhodopean complex thrust, Istanbul thrust, Matoride thrusts, South-East Bulgarian deep complex thrust, Rhodopean thrust or South-West Bulgarian deep complex thrust. The boundaries between them are the well-known from geophysics gravitational transitions (lineaments): the Zlatograd– Yambol and the Strouma–Etropole lineament.

Roumiana Vatseva – Land cover ontology

The term “ontology” comes from the field of philosophy that deals with the study of being. Application of ontology in information technology is associated with the need to create an exact description of the real world or its parts using formal and formalized structures. Gruber (1993) defines ontology as „an explicit specification of conceptualization” or „formal explicit specification of a shared conceptualization” (Gruber, 1995). In the context of computer and information sciences the ontology is defined by Gruber (2009) as a set of representational primitives with which to model a domain of knowledge. The representational primitives are typically classes (or sets), attributes (or properties), and relationships (or relations between members of a class). In the context of database systems, ontology can be adopted as a level of abstraction of datasets, similarly to hierarchical and relational models, but intended for modeling knowledge about individual objects, their attributes, and their relationships with other objects. In the context of knowledge sharing, the term ontology means “a specification of a conceptualization” (Gruber, 2009), or ontology is a description of the concepts and relationships that can exist for an agent or a community of agents. Application of ontology in geoinformation technology enables the sharing and reuse of spatial data, including land cover data, on the most abstract level.

Knowledge for land cover in space and time is organized and structured by conceptual grouping in categories (classes). Land cover refers to the observed biotic and abiotic objects of the earth’s surface (Meyer, Turner, 1992). Land cover is defined by Di Gregorio and O’Brien (2012) as the observed (bio)physical cover of the earth’s surface. It can be considered a geographically explicit feature that other disciplines can use as a geographical reference. Giri (2012) defines land use as the way or man- ner in which the land is used or occupied by humans. Conceptualization of land cover raises important specific issues that are related to the content and boundaries of individual objects, the size of the studied spatial unit and influence of the scale on the research methods and results.

Remote sensing data interpretation covers a range of processes such as abstraction, classification and generalization by which land cover data are extracted based on classification systems. Di Gregorio and O’Brien (2012) argue that for land cover mapping and all other disciplines producing two-dimensional representations of the earth surface, the classification scheme appears in a specific database in the form of a legend. A legend can, therefore, be defined as the application of certain classification criteria (classification rules or classes) in a specific geographical area, using a defined mapping scale and a specific dataset.

The main discussion and question that is still opened in connection with land cover research and application is related to the harmonization and integration of the existing classification systems. Currently there is no internationally accepted reference land cover classification. In this connection, ontology based semantic systems are developed for describing the various taxonomies (classification systems) in land cover domain.

Emil Gachev, Krassimir Stoyanov – The Debeli Namet glacier – Durmitor Massif, Montenegro

The article represents a geographical description of Debeli Namet – the only present perennial ice form on the Balkan peninsula that has been definitely catego- rized as a “classical small glacier”, which is situated in a deep cirque in the Durmitor mountains of Montenegro. Durmitor is part of the main Dinaric chain. It rises up to 2523 m a. s. l. and lies on a karst plateau (Jezersko-Pivska povrs) on 1450–1600 m a. s. l. The presence of perennial ice on the bottom of Velika Kalica cirque at quite a low altitude for these latitudes – 2035–2200 m a. s. l., and respectively at quite high average annual air temperatures (+1°C and more) is possible due to the strong shan- ding, the light, karstified limestone bedrock, and the large amounts of precipitation – to sustain melting the glacier surface must receive an actual amount of 5194 mm/y water equivalent (H u g h e s , 2008), comprising direct atmospheric precipitation on the firn surface of about 2600 mm/y (D j u r o v i ć , 2011), and a contribution of about
3000 mm/y more from avalanche and windblown snow.

The article summarizes results from a fieldwork at the glacier site that took place in October 2011. Then we measured by rope the area of Debeli Namet glacier, and recorded an area of 2.7 ha, which is least than in the autumns of 2005–2010 and more than in 1998 and 2003. Our measurement registered a length of 321 m and width of 136 m in the central part. Clearly observable was the snout at the end of the glacier with a width of 12–20 m.

According to the previous studies (H u g h e s , 2007, 2008) along with our observations, the Debeli Namet glacier shows quite great inter-annual variations of minimal size in autumn. On our old photo from September 1998 the glacier was turned into a shallow snow patch (glacieret). It seems that after a sequence of cold- er and snowyer years (e. g. 2004–2006, and possibly 2009–2010) Debeli Namet gains ice mass, forms a “tongue”, and under the impact of gravity the firn starts a clearly recordable dynamic movement that is in general typical for glaciers. On the opposite – after prolonged periods that consist of dry and warm years (e. g. in the end of the 90s of the last century) the firn mass shrinks to such an extent that the glacier loses its classical morphology and turns into a glacieret, similar to those in the Pirin mountains, that has got very small dynamic downward motion of ice. Therefore, although named a “glacier”, the Debeli Namet in fact periodically turns from the category “classical small glacier” into the category “glacieret”, and vice versa.

Evgeni Baltakov – Internal regional differentiation of Panega karst region

This paper describes morphological features of the Panega karst region, one of the most representatives in the country. It is determined by the geological structure and complex of surface and underground network of forms, on which are running exchanging hydrochemical and transformation processes. The main objective of this paper is to attempt an internal differentiation of Panega karst region and being divided to sub-regions. It is located in the west part of the Central Predbalkan to the watershed of Iskar and Vit Valleys. It covers Yablanishko Bardo – a territory with a classic karst and surrounding hills and valleys periphery – Brestnitsa-Nanovitsa subregion. Besides this main subregion we can define three smaller – Dragoytsa, Belentsi-Oreshene and Ninovtsi-Peshterna. From geological and geomorphological point of view there are some differential factors which give us a reason to recognize such subregions.

Mila Chilikova – Lubomirova – Drought – challenges and measures in hydrological context

Drought as a phenomenon related to precipitations, soil moisture and water resources evidently takes influence on nature, ecosystems, mankind and related to them activities. This obviously insists a multdisciplinary approach, aimed to decrease the possible negative consequences. But practice shows that because of the process behaviour variety there is no uniform approach for ovrcoming the challenges. Even in hidrological aspect the process is a complicated task with direct relation to availability and quantity of water resources. Taking into consideration the importance of problem and its direct connection to water management and climate change and wa- ter scarcity adaptation in help of specialists this paper emphasis upon the drought problems definition and clarification of main conceptual approaches, based on main EU practices. This is of great importance, taking into consideration main principles of Bulgarian and EU legislation, laying down the macro frame for drought measures concerning sector WATERS and Climate Change adaptation. It is done a brief process analysis, concerning both policies and on this base a common approach for hydrologycal process assessment is proposed. It allows establishment of drought monitoring sytem that could be used as a base for for future development of Drought DSS systems. The presented approach is applicible for Bulgarian conditions and could be in help for future investigations concerning development of Drought Management Plans and Drought Risk assessment. As an illustration of the drought assessment approcah practical application of an Automatic drought monitoring system for identification of drought by implementation of SRI in national scale, developed by NIMH-BAS is briefly presented. For clarification of future work purposes concerning drought assessment approach there briefly are presented main challenges with regard to development of drougth indeces concerning widely consideration of consequences with respect to the environment and water scarcity and the development of combined indices that could allow paralel investigation of more than one drought aspects: for example with regard to meteorological and/or agro-aspects and more.

Key words: drought, hydrological drought, drought indices, runoff, drought monitoring systems

Velimira Stoyanova – Applicability of the DRASTIC type index-methods for vulnerability assessment of groundwater arsenic contamination

The article provides an overview of the existing methods for assessing the vulnerability of groundwater contamination, and also of the selection of indicators for assessing the vulnerability of arsenic contamination of groundwater in floodplains.

The concept of vulnerability of groundwater was established in the late 1960s and was widely used in the 1980s and the 1990s. The first definition of Margat(1968) states that vulnerability is: “the degree of protection that the environment provides against the spread of pollution in groundwater”. The definition has been amended through the years, but to the present day there is still no standard definition. It is our opinion that the term “vulnerability of groundwater”, should stand for the ability of chemicals – product of human activity – to reach the water level, remain in solution and go beyond the statutory threshold limit values (TLV) in groundwater.

Different methods for assessing the vulnerability of groundwater exist: index, numerical, simulation and hybrid.

In assessing the vulnerability to a particular pollutant, it is appropriate to use methods designed specifically for that pollutant. In many cases it is impossible to establish a single criterion for the various pollutants because some of the factors favor the migration of some contaminants and prevent the spread of others.

Choosing the most appropriate method to be used for mapping the vulnerability of groundwater in a given area, depends on data availability, as well as on the geomorphological and the hydrogeological characteristics of the area.

In order to assess the vulnerability of groundwater to arsenic contamination in river floodplain terraces, we offer a modification of the DRASTIC index-method, which modification would reflect the features of arsenic migration in landscapes, as well as the geomorphological and the hydrogeological characteristics of the floodplains.

The modified index includes six factors, which are characterized, similar to the DRASTIC, by specific gravity ranging from 1 to 5 (Table 10): depth of groundwater, groundwater recharge, oxidation / reduction potential (Eh) of the soil, mechanical composition of the soil (physical clay), active soil reaction (pH), lithological structure of the aeration zone and filtration properties of the aquifer.

Zoya Mateeva, Anton Philipov – Helio-energy assessment of the Yankovo region

This paper deals with the solar renewable energy resources and with the possibilities to use them for energy output in the region of Yankovo. The factors, which determine the efficiency of the solar resource in the region, are divided into two groups: factors, related to the landforms, and factors, related to the solar (helio-) resource. The first group studies the slope exposure and gradients, the orographic openness, the availability of protected sites under the European Ecological Network NATURA 2000, the transport access and land use. These relief features have to be considered so as to take the right decision about the optimum positioning, construction and maintenance of helio-facilities. The second group of factors studies the helioenergy resource, based on the sunshine duration, the intensity of solar radiation and the energy potential of these climate resources. In order to assess them, the following characteristics have been taken into account: total cloudiness, number of clear and dark days, number of days without sunshine, etc. The authors have made some recommendations of practical importance, including the risk assessment, connected with improper utilization of solar renewable resources for energy production in the region. Attention is also paid to the risk, resulting from the adverse climatic and geo-dynamic processes and phenomena as well as from certain regulatory and administrative barriers.

Chad Staddon, Stefan Genchev – Екологично отношение и поведение на българското население от Разложката котловина към околната среда: резултати от 10-годишно изследване

This paper explores certain dimensions of the transformation in attitudes towards the environment in one largely rural locality of Southwestern Bulgaria. While there has been much attention paid to general and national-scale issues in postcommunist environmental reconstruction (e.g. C a r t e r, T u r n o c k, 2002; P e t e r s e n, 1993), relatively little research exists that examines the specifically local impacts of broader postcommunist transformational processes.

Tomasz Komornicki, Piotr Rosik, Marcin Stępniak – Transport accessibility in Eastern Poland

The purpose of the paper is to assess the current accessibility in the macro-regional and provincial setting of Eastern Poland and the simulation of changes, which may take place owing to the realisation of the large-scale investment programs. The indicator of potential accessibility was used. The analyses and simulations confirmed that there is a need to improve the accessibility of the area, first of all through construction of transport routes of high speed, linking main centres of Eastern Poland with Warsaw, Cracow and Gdansk. Improvement of accessibility within the area of Eastern Poland may be realised also by implementation of investment projects located in other regions, and in particular – in central Poland.

Kunzi Zhu, Jinming Sha, Yuqin Liu, Saiping Xu, Rumiana Vatseva – Analysis of spatial and temporal changes of informatization in China

Since China‘s entry into the information society, the researchers have discovered the ex- istence of the “digital divide” among regions. For this phenomenon, researches were focused on economics perspective, but lack of scale thinking in geography. Based on literature review, correlation analysis and anlysis of the hierarchy process, it is established informatization development index (IDI), and then calculated IDI for the 31 provinces in China in 2001-2011. The findings of this study are as follows. Firstly, national IDI steadily improved from 2001 to 2011. Secondly, there are significant regional differences in informatization, and the IDI declines gradually from Eastern China to Western China. From 2001 to 2011, the development of IDI in Eastern China is faster than Central China and Western China, and the regional digital gap is becoming bigger. While, the development of IDI in Western China is faster than Central China, and the regional digital gap is becoming smaller. Finally, provincial digital gap in Western China is smaller than before, but in Eastern China it is becoming bigger. In addition, the study also shows that China‘s informatization is the response of economy, but the polarization degree of informatization is larger than economy.

Key words: informatization development index (IDI), scale, digital divide, spatial – temporal change, China

Gergana Metodieva – Publishing activity of the Department of Geography at the National Institute of Geophysics, Geodesy and Geography at the Bulgarian Academy of Sciences (1950-2011)

The paper „Publishing activity of the Department of Geography at the National Institute of Geophysics, Geodesy and Geography at the Bulgarian Academy of Sciences (1950-2011)” is a continuation of two previous publications, printed in this journal. The current paper makes a comparative analysis of the contents, structures, and the teams of authors in the different editions (collections, atlases and books). The publishing activity of the Institute is related to its structure, the nature of research and to the specificity of the geographical sciences as a branch of the scientific knowledge in general. Publishing of the Institute’s scientific output is of great importance for the promotion and the distribution of its scientific product across the country and abroad. The performed survey on the publishing activity shows that during the period 1950-2011,a total of 17 monographs, 13 proceedings, 3 atlases and three other books were issued by the Institute. During this period two series – “Proceedings of the Institute of Geography” journal (1951-1974, comprising 16 volumes) and “Problems of Geogra- phy in the People’s Republic of Bulgaria” journal (1964 to 1978 – 5 volumes), were issued, as well as the “Problems of Geography” journal (1974-2011, a total of 144 vol.). The issuing of the latter one continues to-date.

Georgi Zhelezov – Integrated assessment of the natural and technological ha- zards of the Danube floodplain in the Romanian – Bulgarian cross-border section between Calafat-Vidin and Turnu Măgurele–Nikopole

The project is aiming to improve the already existent information on natural and technological hazards on both Romania and Bulgaria border area and increase transparency in terms of availability and dissemination for all the interested actors (local government, municipalities, emergency situation inspectorates etc.).

Tsvetan Kotsev – Arsenic contamination of the Ogosta River – relation between the soil biochemical processes in the floodplain and the river dynamics

Ivanka Boteva – Geography – a Universe of knowledge

Ivanka Boteva – Prof. Ivan Batakliev

Marian Varbanov – Third edition of the book “The mountains in Bulgaria”

Georgi Alexiev – Professor Bozhidar Mavrudchiev at the age of 80