Depopulated or abandoned spaces are a consequence of the emptying of settlements and the complete disappearance of the human factor in the use of space. The aim of this paper is to determine the size and structure of this space—clusters that can be considered abandoned at the regional level. In the focus of this paper is the space at the district level in Serbia, within which significant changes in land use occurred in the period 1990–2018. Time series of formal databases and data obtained by GIS tools were analysed in order to observe the changes in the structure of surfaces and to define the trend of merging or increasing the empty space during the last two decades. This paper analyses planning documents and strategies in order to determine with which problems the state identifies abandoned areas and what planning solutions are possible. A new method for calculating the homogenization of abandoned space is presented. The results indicate the homogenization of the abandoned space in the border regions in the south of Serbia, as well as major changes in land use, such as reforestation and reclamation of agricultural land.

The article deals with the complex dynamics of depopulation in rural areas in Serbia. Although the topic has been very topical in recent decades and research has long identified the causes and consequences of depopulation in numerous regions in Europe, there seems to be no systematic approach to the implementation of policies for the management of abandoned areas. We started from already known factors contributing to depopulation, including economic, social and environmental dimensions. Based on previous research, historical trends and a statistical database, we attempted to represent depopulation as a spatial process that has its own size, structure and consequences, using a new, quantitative methodology for grouping abandoned areas into clusters as basic units of dispersal of depopulated areas. The aim of the work was to quantitatively determine the size and structure of the depopulated area in Serbia after the 2022 census. The study opened up new fields of research for the future use of depopulated space, but also offered certain solutions for policy makers, researchers and municipalities struggling with the challenges of depopulation. The results of the work show the existence of 47 abandoned clusters in 10 administrative regions of Serbia, which is 17 more than in the 2011 census. Further homogenization and consolidation of clusters was found in the statistical regions: Toplička, Zaječarska, Jablanička, Pirotska and Raška region, i.e. an increase in the total depopulated area as well as its spatial expansion towards the north of the country.

Tourism is a significant segment of development policy at the national level, and it is important in terms of contributing to the Gross domestic product (GDP) diversifying of economy, reducing disparities between regions, fostering development capital, and promoting regional development. Tourism greatly contributes to the sustainable development of a region and a unit of local self-government, in an environment where sometimes there are no other alternatives for achieving that goal. Theories of regional development and tourism have evolved over a similar period after the Second World War. The concept of regional development has undergone a significant transformation through various theories. The paper analyzes the main principles of the theory of endogenous regional development and the possibility of its application for tourism research as a development factor. Tourism development policy is often created by the views of these theories. The purpose of this paper is to indicate, based on the analysis of modern ideas and approaches to regional development, whether they are suitable for the study of tourism and which factors are decisive in achieving its development function. The paper points out certain elements of theories that can individually or together represent the theoretical basis for tourism development planning in regions and local government units.

Global energy demand is steadily increasing, accompanied by a growing emphasis on clean and renewable energy sources. Serbia possesses significant solar energy potential, with solar radiation levels among the highest in Europe—about 40% above the European average. Within this context, rural depopulation clusters offer attractive opportunities for solar energy development due to the availability of underutilized land. This study aims to identify optimal locations for solar power installations in Serbia’s depopulated areas by applying multi-criteria decision-making methods under uncertainty. A hybrid framework, combining fuzzy Analytic Hierarchy Process (fuzzy AHP) and fuzzy MULTIMOORA, was employed to evaluate potential sites. Fuzzy AHP was used to determine the relative importance of criteria, while fuzzy MULTIMOORA ensured a robust ranking of alternatives by addressing the vagueness in data and expert judgments. The analysis identified several high-potential brownfield locations, with the most suitable land class covering 5.01% (16.94 km²) of the examined cluster area (311.3 km²). These areas are typically characterized by flat terrain, high solar irradiation, and minimal environmental constraints, providing favorable conditions for solar farms. Among the assessed sites, location no. 9 consistently ranked highest across all three fuzzy MULTIMOORA variants: FRPA (z = 0.0588), FRS (y = 0.2811), and FFMF (p = 1.6748). The findings confirm that the hybrid fuzzy AHP–MULTIMOORA approach offers valuable support for informed decision-making on solar energy deployment in depopulated rural regions. Moreover, the utilization of rural brownfield sites contributes to the expansion of renewable energy, rural revitalization, and sustainable land management in Serbia.