Eastern Bulgaria Research Articles

A new view to the spatial distribution of the Paleogene lithostratigraphic units in the Goren Chiflik Horst based on borehole data

The present article aims to provide new data on the spatial distribution and lithological features of the Paleogene lithostratigraphic units in the Goren Chiflik Horst, which is part of the Moesian Platform in Eastern Bulgaria. Eight formal Paleogene lithostratigraphic units were recognized on the basis of primary lithological data derived from 29 borehole sections. They are as follows: the Komarevo Fm. (Thanetian), the Beloslav Fm. (Ypresian), the Dikilitash Fm. (Ypresian), the Aladan Fm. (Ypresian), the Avren Fm. (uppermost Ypresian–lowermost Priabonian), the Dvoynitsa Fm. (Lutetian), the Dolni Chiflik Mb. of the Avren Fm. (Bartonian–Priabonian), and the Ruslar Fm. (Oligocene). Their spatial distribution and relationships are visualized by drawing up 11 geological cross-sections. Additional data on their lithology, thickness, boundaries and age are also given.

New data on the Paleogene lithostratigraphic units’ distribution in the Avren Step south of Varna and Beloslav Lakes based on borehole data and seismic profiles’ interpretation

The present article aims to provide new data on the spatial distribution and lithological features of the Paleogene lithostratigraphic units in the Avren Step, which is a part of the Moesian Platform in Eastern Bulgaria. On the basis of primary lithological data derived from 81 boreholes’ sections and lithostratigraphic interpretation of five seismic profiles, six formal Paleogene lithostratigraphic units were recognized. They are as follows: the Komarevo Fm. (Thanetian), the Beloslav Fm. (Ypresian), the Dikilitash Fm. (Ypresian), the Aladan Fm. (Ypresian), the Avren Fm. (uppermost Ypresian–Priabonian), and the Ruslar Fm. (Oligocene). Their spatial distribution and relationships in the northern part of the studied area are visualized by drawing up of five geological cross-sections, while the deep geological structure of the southern part is shown by lithostratigraphic interpretation of the five seismic profiles. Four of the units (the Beloslav, Dikilitash, Aladan and Ruslar Formations) demonstrate almost constant lithology throughout the whole studied area with some variations in their thickness. The Komarevo Formation, and especially the Avren Formation, show considerable lithologic and thickness variability.

Cyanoprokaryotes biodiversity in nine shallow Bulgarian wetlands

The results from the investigation of the phytoplankton in nine shallow wetlands, situated in Central and Eastern Bulgaria, conducted in the frame of recent projects related to identifying harmful algal blooms and algal toxins in the country are demonstrated. Therefore, the focus is on the cyanoprokaryotes and their toxigenic species in particular. The species were identified using conventional light microscopy, while for distinguishing the toxigenic species and strains PCR-based molecular methods were applied. Cyanoprokaryotes comprised about 30% of the total phytoplankton biodiversity of the studied wetlands and were unevenly spread among them. The presence and spread of toxigenic strains in the studied wetlands also did not show any strong geographical pattern. Taxonomic problems related with the evaluation of the real cyanoprokaryotic biodiversity and potential alien or invasive character of the morphospecies are discussed.

Varia: Старобългарският превод на Псевдозлатоустовото „Слово за Усекновение на Йоан Кръстител“ (BHG 859)

The article proposes an analysis of three copies of the Pseudo-Chrysostomian Homily on the Beheading of St.John the Baptist. The textological, lexical and grammatical characteristics of Slavonic copies under examination,when compared with the Greek text, support the opinion that the homily was translated during the Old-Bulgarian period, in eastern Bulgaria, in the 10th century. The observations on the translation methods testify to its high quality and that the free choice of correlates established at some places often makes the text more accessible to the Slavic audience.

Hepatitis C virus genotype analysis in patients with chronic hepatitis in North Eastern Bulgaria

Background: The main objective of this study was to analyse the spread of hepatitis C virus (HCV) genotype in patients with chronic liver disease; commenting on the molecular characterization of HCV and gender and age in Varna, Bulgaria. Across Europe and the world, HCV is a significant economic concern and public health crisis. Defined by genotype variations, HCV is the leading cause of chronic liver disease, liver related morbidity, and mortality worldwide. Active examination for asymptomatic patients is essential, initiating early treatment aimed at the specific HCV genotype, effective outcomes, and reducing transmission and mortality in Bulgaria.Methods and materials: Nucleic acid extraction and amplification were performed with commercially available test kits on 115 patients blood samples collected from March 2018 to October 2018. Male (n = 58) (50.43%, 95% CI = 41.29%–59.57%) and female (n = 57) (49.57%, 95% CI = 41.29%–59.57%) samples were equally distributed (mean age = 51.4 years; SD = ±16.5 years; range = 17–87 years old).Results: Genotype 1b predominated (73%, 95% CI = 64.89%–81.11%), followed by high prevalence of 1a (13.9%, 95% CI = 7.58%–20.22%) and 3 genotypes (11.3%, 95% CI = 5.51%–17.09%). Genotypes 2 and 4 were equally the least prevalent (0.9%, 95% CI = −0.83%–2.63%). In genotype 1b, 60.7% were women and 39.3% were men; in genotype 1a, 25% were women and 75% were men; and in genotype 3, only 7.7% were women and 92.3% were men. Males were most prevalent in genotypes 1a (75%) and 3 (92.3%), while women were most prevalent in genotype 1b (60.7%).Conclusions: HCV genotype lb is the predominant variant within the epidemiological pattern of HCV genotypes in patients with chronic liver diseases in North Eastern Bulgaria.

Distribution of the meadow lizard in Europe and its realized ecological niche model

ABSTRACTOne of the most interesting but elusive members of the European herpetofauna is the meadow lizard (Darevskia praticola). It is a small, ground dwelling, predominantly forest living lacertid, for which many ecological and biological data are still missing. Moreover, at least for the western part of the species range (south-eastern Europe) its distribution and environmental associations are insufficiently known, likely due to difficulties in detection even with intensive field sampling. Here, we complemented the available literature records with our personal observations and explored the effects of environmental factors shaping the species ecological niche and distribution in Europe using the ecological niche modelling approach from Maxent software. The new records of the meadow lizard fill a gap in its known distribution. The most suitable habitats are in central and eastern Serbia, south-western Romania, and central, southern and south-western Bulgaria. Mean temperature of the coldest quarter, vegetation and slope had the strongest effect in defining the meadow lizard’s ecological niche. Niche suitability increased with the increase in forest cover and slope, while the temperature showed a bell-shaped response with a rather narrow tolerance range for temperature. Contrary to expectations, precipitation seemed to have no contribution to the species occurrence. Ecological niche model performance increased with a higher resolution of predictor variables despite the lower number of available occurrence records, although the slope variable had a greater predictive power when calculated at a lower resolution. Interestingly, high resolution vegetation variables (30 m) were able to show some level of habitat fragmentation, which likely resulted from deforestation. Overall, our results epitomize the effects of limited sampling on the biogeography inference of elusive species while having significant repercussions on conservation priorities and management of the species.

Illite/smectite diagenesis and thermal evolution of Lower Cretaceous–Paleogene successions in the Dolna Kamchiya Depression, Eastern Bulgaria

The diagenesis of mixed-layer illite/smectite (I/S) minerals in Lower Cretaceous–Paleogene successions from the Dolna Kamchiya Depression was studied, using X-ray diffraction analysis of the clay fraction (<2 μm) from core samples. The proportion of illite in I/S and degree of ordering increase with depth irrespective of the geological age, indicating that highly expandable I/S compositions were progressively illitized during the burial evolution. Lowest smectite values are recorded in the Lower Cretaceous deposits, whereas in the Paleogene sections are documented great regional variations in the I/S mineralogy, caused by differential basin subsidence. The transition from randomly interstratified (R0) to R1-ordered I/S occurs between depths of 2200 m and 2400 m, and crosscuts the major stratigraphic boundaries. The variable patterns of I/S depth profiles resulted from the combined influence of temperature, burial history, sedimentation and subsidence rates, and basin geodynamic types on diagenesis. The rapid increase in illite content in the I/S clays across the main unconformities reflects the great thickness of eroded sediments during uplift and denudation events and/or elevated heat flow. The reconstructed palaeogeothermal gradient for the Eocene after corrections for decompaction and erosion would correspond to the values for foreland basin settings reported in the literature. Application of the I/S geothermometer to the Lower Cretaceous–Paleogene rocks demonstrates a general trend of increased organic maturity toward southeast in relatively isochronous deposits. The new results appear to be the first record for the effect of a multiphase basin evolution on the smectite illitization in sedimentary successions from the Dolna Kamchiya Depression.

Demographics and Incidence of Histologically Confirmed Intracranial Tumors: A Five-year, Two-center Prospective Study.

IntroductionIntracranial tumors (ICTs) are a diverse group of malignancies that pose an immediate threat to patients' lives, no matter their local or metastatic origin, benign or malignant nature. These lesions have severe clinical courses and need to be diagnosed and treated as soon as possible, with pathological verification being the pivotal moment in the process of determining curative modalities.AimThe aim of this study was to compare the incidence of histologically confirmed ICTs in Eastern Bulgaria, based on their type (primary, metastatic, and non-volume occupying lesions (NVOL)), their respective subtypes, and incidence in a descriptive manner.Materials and MethodsFor a period of five full calendar years (January 1st, 2012 – December 31st, 2016), all histologically confirmed cases of intracranial tumors were prospectively collected from two individual tertiary healthcare institutions. The cases were then statistically analyzed in a descriptive manner, and incidences of primary, metastatic, and NVOL were compared with regards to their specific origins, types, and subtypes. Metastatic tumors were further segregated relative to their intracranial metastatic location.ResultsThe total number of individual ICTs registered in the set timeframe was 822. Primary ICTs represented a total of 66.12% of the histologically confirmed cases, with the most common entries being tumors from a glial and meningeal origin, 30.90% were histologically confirmed as metastatic ICTs, from which the most common entries were of pulmonary origin, and the other 2.94% were NVOL. On behalf of their intracranial metastatic location, metastatic tumors were located predominantly in the supratentorial region, represented as a total of 87.80%, while the other 12.20% were located in the subtentorial region. Based on the descriptive analysis, the annual incidence per 100,000 capita of all ICTs is 9.12, comprised of 6.03 per 100,000 for primary ICTs, 2.82 per 100,000 for metastatic ICTs, and 0.27 per 100,000 for NVOL. The annual incidence of the most commonly diagnosed primary ICTs per 100,000 is 2.36 for meningioma, 2.03 for glioblastoma, and 0.48 for pituitary adenoma. The annual incidence of the most commonly diagnosed metastatic ICTs per 100,000 is 1.32 for lung cancer metastases, 0.28 for gastrointestinal tract (GIT) metastases, 0.22 for melanoma, and 0.17 for breast cancer metastases.ConclusionBased on our results, primary ICTs are operated and biopsied more than two times as much as metastatic ICTs and only a small fraction of neurosurgical interventions are undertaken due to NVOL. Metastatic ICTs are predominantly supratentorial with no evidence of a tumor predominantly metastasizing in the subtentorial region. The demographics reported in the study establish some aspects of age and gender preferences, as well as the annual incidence per 100,000 for the most commonly diagnosed types of ICTs in our population.

Gold and “silver-like“ (graphite) glittering decoration: Symmetry patterns on Chalcolithic (5th mill. BC) pottery from eastern Bulgaria

Gold and “silver-like“ (graphite) glittering decoration: Symmetry patterns on Chalcolithic (5th mill. BC) pottery from eastern Bulgaria

Haemosporidian blood parasite diversity and prevalence in the semi-collared flycatcher (Ficedula semitorquata) from the eastern Balkans

We present the first survey on prevalence and diversity of haemosporidian parasites of the genera Plasmodium and Haemoproteus in a poorly studied migratory passerine, the semi-collared flycatcher (Ficedula semitorquata). In total, 110 individuals were sampled during two breeding seasons in Eastern Bulgaria. We collected both blood samples for PCR identification and blood films for microscopic identification of haemosporidians. We found six distinctive parasite cyt b lineages present in the blood of the semi-collared flycatcher (three Haemoproteus and three Plasmodium). Two of the lineages, i.e. pWW3 of Plasmodium sp. and hCCF2 of Haemoproteus sp., are recorded for the first time in the family Muscicapidae. The overall prevalence ranged between 12.2 and 15.9% and we did not find co-infections. We hypothesize that the low prevalence of haemosporidians in this species might be linked to its small population size and relatively restricted geographical range.

Aquatic SnailsEcrobia maritima(Milaschewitsch, 1916) andE. Ventrosa(Montagu, 1803) (Caenogastropoda: Hydrobiidae) in the East Mediterranean and Black Sea

In the paper cytochrome oxidase subunit I (COI) in minute gastropods Ecrobia has been sequenced from five localities at the Black Sea (Pomorie Lake and Constanza) and eastern Mediterranean (Gulf of Corinth, Evvoia Island, Attica). Pomorie Lake, a hyperhaline lagoon in eastern Bulgaria, harbours a population of Ecrobia maritima, whose shell and penis morphology are presented. COI partial sequences of E. maritima from Pomorie Lake differ markedly from those in the two Aegean populations not studied so far (Evvoia Island, Attica), and from another four studied earlier, scattered across the Black Sea and Aegean Sea. Such a high level of divergence was unexpected, since Pomorie Lake is only about 20 km away from the closest known locality of E. maritima (Burgas, Bulgaria). The mean p distance within E. maritima was 0.0113. A similar value of p distance (0.0137) was found within the clade grouping all the haplotypes of E. ventrosa. Mean genetic distance between these two species is p = 0.048. E. ventrosa inhabits western Europe, Tunisia, the Peloponnesus and the Corinthian Gulf (Itea: present study), both in the Ionian Sea, and — surprisingly — the coast of the Black Sea in Romania (Constanza: present study). E. maritima was found in the Black Sea and the Aegean Sea. Estimated time of divergence between the species is 3.30 ± 0.23 Mya, and 1.00 ± 0.11 Mya between E. maritima from Pomorie Lake and the other studied localities. The observed pattern is discussed in the context of the geological history of the region, especially glaciation events. Speciation of E. maritima in the Ponto-Caspian waters isolated from the Mediterranean in the Late Piacenzian and divergence of the population presently occurring in Pomorie Lake during the local Calabrian salinity crisis are postulated.

The possibility of computer analysis of the twilight soundscape of the orthopteran (Tettigoniidae, Gryllidae) community, by the example of an agrocenosis in Eastern Bulgaria

Computer analysis of the twilight soundscape with the sounds of grasshoppers (Tettigoniidae) and crickets (Gryllidae) recorded in an agrocenosis of Eastern Bulgaria was performed. Seven species were identified by the dynamic spectrograms. It is shown that analysis of the group stridulation spectrograms of Ensifera can be useful not only for solving ecological and faunistic problems but also for studying the acoustic interactions of conspecific and heterospecific individuals in the same biotope.

Demographic Changes and Visual Disability and Eastern Bulgaria

Introduction : Age and gender are among the risk factors influencing the disability. Purpose : To study the connection between the demographic changes in Eastern Bulgaria and frequency of disability. Material and methods : The blindness and low vision were evaluated retrospectively and calculated per population of 100 000. All information was obtained from the National Statistical Institute and the Specialized Visual Labor Expert Medical Commission - Varna registry for the period 2005-2012, filled in a specifically designed data collection form, and subsequently processed with SPSS 20. Results and discussion : The data from the NSI shows an increase of the population above 60 years of age from 2009. The individuals up to 19 years of age are 4.90 %, and those of 20 years of age and above are 95.19 %. The primary disability (PD) starts to increase after the age of 60 and decreases to a small extent within the age group above 80 years. The majority of the patients are city residents. Regarding the gender indicator it has been demonstrated that contrary to monocular blindness where the male PD prevails, for binocular blindness above the age of 80 the PD women are more affected. Conclusions : PD for individuals with visual conditions increases in correlation with general tendency of the population ageing.

New localities of Battarrea phalloides (Basidiomycota) in Bulgaria

Battarrea phalloides, a rarely found basidiomycete which is included in the Red List of fungi in Bulgaria and also in the Red Data Book of the Republic of Bulgaria with threat status EN B2a(i,ii,iv), has been recorded in two new localities in Eastern Bulgaria near to the Black Sea coastal region. The paper provides data on macro- and microscopic description of the basidiomata, coordinates, and map of distribution of the fungus in Bulgaria.

Славянский перевод апокрифа "Didascalia Domini / Откровение святым апостолaм" (BHG 812a-e)

The New Testament apocryphon Didascalia Domini is one of the least known. Its original was written in Greek, according to François Nau, at the end of the 7th century. Relatively early it was translated into Old Church Slavonic. At present five copies of this translation are known, stretching from the 13th to the 15th century. Three of them belong to the Serbian redaction, one each to the Russian (East Slavic) and to the Middle Bulgarian redaction. According to Michail Nestorovič Speranskij the translation originated in Bulgaria. The Greek copies, the oldest of which stems from the 11th century, have divergent final chapters. Moreover, the Slavic translation has yet another ending not corresponding to any of the Greek texts. The textological analysis of the five Slavic copies makes it possible to get an idea of their mutual relationship. On the basis of the linguistic archaisms of the text one can surmise that the translation has been made in Eastern Bulgaria during the 11th century. At the end of the paper there is a critical edition of the Slavic text.

Trends in registered blindness in eastern Bulgaria

Purpose : The purpose of the study was to evaluate the incidence and causes of registered blindness and low vision in Eastern Bulgaria. Methods : Documentation per each included patient based on archives of the Expert Disability committee was evaluated and divided in two intervals. The cumulative incidence per 100 000 was calculated in 3 severity groups for bilateral and monocular blindness and by residence. Results : The incidence of binocular blindness decreased from 63.79 to 41.61 for males and from 64.21 to 41.14 for females during the second period. Meanwhile, monocular blindness increased from 41.14 to 65.14 for males and from 33.01 to 48.83 for females. It rapidly increases after 60 years of age and is the highest for those over 80. Patients with visual acuity (VA) below 0.05 comprise 40-35%, between 0.06 and 0.1 - 22- 35%, and 0.15 to 0.3 - 38-34%. The proportion and incidence of patients with VA below 0.05 have decreased two times during the second period among residents of cities and remained high - 42-48% in the rural population. Severe monocular blindness was significantly higher among males across the whole population. In the age group below 19 years, the leading causes of binocular blindness were retinopathy of prematurity (ROP), congenital glaucoma, microphthalmos and congenital cataract and for monocular impairment - trauma and amblyopia. For those above 20, the main causes were glaucoma, end-stage diabetic retinopathy, cataract - both with significant reduction in the incidence, AMD and trauma. Conclusions : Systematic evaluation of the deteriorated quality of life and estimation of the cost of vision loss and eye diseases to individuals and their families as well as extended family caregivers and thirdparty payers, the health care system and Bulgarian society is essential in the development of evidence-based interventions that translate research into enhanced clinical and community practice and prevention of unnecessary visual impairment.

The genetic structure of wild Orobanche cumana Wallr. (Orobanchaceae) populations in eastern Bulgaria reflects introgressions from weedy populations.

Orobanche cumana is a holoparasitic plant naturally distributed from central Asia to south-eastern Europe, where it parasitizes wild Asteraceae species. It is also an important parasitic weed of sunflower crops. The objective of this research was to investigate genetic diversity, population structure, and virulence on sunflower of O. cumana populations parasitizing wild plants in eastern Bulgaria. Fresh tissue of eight O. cumana populations and mature seeds of four of them were collected in situ on wild hosts. Genetic diversity and population structure were studied with SSR markers and compared to weedy populations. Two main gene pools were identified in Bulgarian populations, with most of the populations having intermediate characteristics. Cross-inoculation experiments revealed that O. cumana populations collected on wild species possessed similar ability to parasitize sunflower to those collected on sunflower. The results were explained on the basis of an effective genetic exchange between populations parasitizing sunflower crops and those parasitizing wild species. The occurrence of bidirectional gene flow may have an impact on wild populations, as new physiological races continuously emerge in weedy populations. Also, genetic variability of wild populations may favour the ability of weedy populations to overcome sunflower resistance mechanisms.

Y-Chromosome Diversity in Modern Bulgarians: New Clues about Their Ancestry

To better define the structure and origin of the Bulgarian paternal gene pool, we have examined the Y-chromosome variation in 808 Bulgarian males. The analysis was performed by high-resolution genotyping of biallelic markers and by analyzing the STR variation within the most informative haplogroups. We found that the Y-chromosome gene pool in modern Bulgarians is primarily represented by Western Eurasian haplogroups with ∼ 40% belonging to haplogroups E-V13 and I-M423, and 20% to R-M17. Haplogroups common in the Middle East (J and G) and in South Western Asia (R-L23*) occur at frequencies of 19% and 5%, respectively. Haplogroups C, N and Q, distinctive for Altaic and Central Asian Turkic-speaking populations, occur at the negligible frequency of only 1.5%. Principal Component analyses group Bulgarians with European populations, apart from Central Asian Turkic-speaking groups and South Western Asia populations. Within the country, the genetic variation is structured in Western, Central and Eastern Bulgaria indicating that the Balkan Mountains have been permeable to human movements. The lineage analysis provided the following interesting results: (i) R-L23* is present in Eastern Bulgaria since the post glacial period; (ii) haplogroup E-V13 has a Mesolithic age in Bulgaria from where it expanded after the arrival of farming; (iii) haplogroup J-M241 probably reflects the Neolithic westward expansion of farmers from the earliest sites along the Black Sea. On the whole, in light of the most recent historical studies, which indicate a substantial proto-Bulgarian input to the contemporary Bulgarian people, our data suggest that a common paternal ancestry between the proto-Bulgarians and the Altaic and Central Asian Turkic-speaking populations either did not exist or was negligible.

Structural and depositional evolution of the East Balkan thrust belt, Bulgaria

Analysis of structural and sedimentologic data from onshore outcrops, offshore wells, and offshore seismic profiles indicates that the thrust belt geometry in eastern Bulgaria from the Paleocene to the Holocene is characterized by a southeastward plunge toward the western Black Sea Basin. This plunge was caused by (1) a combination of eastward-thinning continental crust in the west and oceanic crust in the east; (2) a postrift thermal subsidence of the continental crust; (3) buttressing and no buttressing of the Moesian platform against the thrust belt in its western and eastern parts, respectively; and (4) northeastward thrust belt advance. These factors controlled the overall eastward-diminishing uplift of the thrust belt and associated eastward sediment funneling into the Black Sea. Evidence for the eastward-fading uplift and buttressing includes the (1) eastward decreasing amount of shortening along constructed cross sections, yielding 30, 10.5, 11, and 4 km (18.6, 6.5, 6.8, and 2.5 mi, respectively) from west to east, respectively; (2) eastward trend of more complete stratigraphic sections and shallower erosional levels; and (3) eastward increase in decollement depths, being 3.7, 3.8, 9.5 to 13.5, and 12.3 to 14.1 km (2.3, 2.4, 5.9–8.4, and 7.6–8.8 mi). The age of the last thrusting is progressively younger toward the east from the middle Eocene through the late Eocene to the Oligocene from west to east, respectively. Onshore parts of the thrust belt, which were significantly affected by buttressing against the Moesian platform, exhibit thrusting followed by late Eocene gravitational collapse, Oligocene quiescence, and Neogene extension. The thrust belt part farther east exhibits thrusting followed by Oligocene–Neogene extension. A Paleocene–middle Eocene piggyback basin formed in the onshore part of the thrust belt, centered in the East Balkan zone, with a southeastward-plunging axis, which migrated northeastward with basin shortening and filling. The development of the East Balkan thrust belt and its later extensional modification had a dominant control over sediment transport, lithofacies, and depositional patterns. Developing thrust belt fold structures, together with the orogenic hinterland and highs in the foreland, formed a northeastward and eastward expanding system of sediment input. Southeastward-plunging axes of the foreland basin and the Paleocene–middle Eocene piggyback basin were the principal sediment transport pathways, together with subordinate internal synclinal axes. These depressions funneled sediments toward and into the western Black Sea Basin. As orogenesis advanced to the northeast, former depositional areas were uplifted and eroded, providing local sources of sediment.

Determining of the morpholithology types in the Kamchia River basin (Eastern Bulgaria) by means of geographic information system (GIS)

The article presents the morpholithology types in the Kamchia River basin (Eastern Bulgaria) - the catchment area of the largest Bulgarian river which flows into the Black Sea. These types are determined on the base of information about the relief and lithological substrate. The rocks in the investigated area are divided into groups accord­ing to their physical-mechanical and chemical composition, and the relief types are determined in regards to the morphographic features of the catchment area. The research is done on the base of geological and topographic maps in scale 1:200 000 and also terrain observations are taken into account. As a result of the research a map of morpholithological types (1:200 000) is made. The map shows a considerable variety of the morpholithological types in the Kamchia River basin. This variety determines the appearance of the territory and also influences on the landscape differentiation. The analyses and composition of the morpholithology map are done in GIS envi­ronment. For that purpose a GIS database of lithology and relief (topography) of the Kamchia River basin is built as spatial 'overlay' analysis is done.