TRANSPORT ACCESSIBILITY OF ADMINISTRATIVE CENTRES IN SUMY OBLAST: A SPATIAL-GEOGRAPHICAL APPROACH

Abstract

The article focuses on the assessment of transport accessibility of district centres in Sumy region using graph theory methods.The transport network was represented as a weighted undirected graph, with distances between centres measured along the shortest road routes. Five key locations were selected as the subject of the study – regional centers in the region: Sumy, Romny, Konotop, Okhtyrka, and Shostka. The analysis applied a set of topological metrics, including the sum of shortest path lengths (absolute accessibility index), eccentricity (maximum shortest distance), as well as relative indices of Bavelas and Beauchamp, which normalize absolute values and allow comparing nodes within a single network and identifying “central” and peripheral positions. Additionally, the average values of the indices for the network as a whole are generalized, which makes it possible to characterize its integration. The calculations were performed using the Python software environment and libraries for graph and data array analysis NetworkX and NumPy, which ensures the reproducibility of the procedures.The results demonstrate a clear differentiation in the level of accessibility among the five analysed centres. Sumy and Romny show the most favourable positions, characterised by lower sums of shortest path lengths and smaller eccentricity values, which indicates their relative centrality in the regional network. Konotop occupies an intermediate position, while Okhtyrka and Shostka display higher eccentricity and lower centrality values, reflecting their more peripheral roles. At the network level, the indices reveal moderate connectivity, with accessibility influenced by spatial configuration and inter-settlement distances.The study highlights the potential of graph-theoretical approaches for analysing regional transport structures. The findings may serve as a basis for improving transport policy, optimising inter-district connections, and prioritising infrastructure investments in Sumy region.