4. Mountains and Mountain Regions in Bulgaria

The mountains in Bulgaria occupy almost half of its area (47.54 %). The geographic situation of the country, the present-day differentiation and variety of the relief, and its combination with other natural components affect the economic management of the mountain regions. This research provides a comparative analysis of the changes in the territorial extension of the mountain regions according to the criteria approved in recent years [before and after Bulgaria’s accession to the European Union (EU)]. According to the EU Regulations, the mountain regions are defined as unfavorable, with limited capacities for land use and with higher costs for performing agricultural activities. Among the groups of criteria, set in different normative documents and projects, special attention is paid to the criterion above sea level altitude. The mosaic nature of relief and the great number of landscape types in Bulgaria require that the complex impact of the physical geographic factors should be taken into consideration while determining the lower boundary of the mountain regions. In research work, however, to be in compliance with the aims of each investigation and to achieve unbiased scientific results, we have to observe either the boundaries already specified in the normative documents or the physical geographic borders.