External development potential of brownfield sites in the Czech–Polish cross-border post-industrial region: A network-based assessment

Brownfield transformation is not only a technical and environmental task, but increasingly a cross-scalar governance challenge, particularly in European cross-border regions where planning systems, legislation and development trajectories intersect. The study examines brownfield sites in the cross-border region of Moravian-Silesian Region (Czech Republic) and Silesian Voivodeship (Poland). It pursues two aims: to harmonise and characterise brownfields across contrasting planning contexts, and to assess how network-based accessibility zones relate to the socio-economic development potential of surrounding municipalities. The study introduces a harmonised method for delimiting brownfield sites, defined as post-mining and post-industrial areas that may be contaminated and partially reused, and develops a Composite Index of External Development Potential as a contextual screening tool integrating five external socio-economic indicators relevant to post-industrial redevelopment contexts and comparative spatial assessment. The 595 identified brownfield sites reveal pronounced cross-border differences in size structure and spatial concentration, with smaller, clustered sites in Moravian-Silesian Region and larger, more dispersed sites in Silesian Voivodeship. Accessibility-based analysis shows clear socioeconomic gradients, with the weakest external development potential near brownfields and progressively more favourable conditions at greater network distances. K-means clustering distinguishes three municipal types, highlighting contrasting socio-economic contexts in which brownfields are embedded across the cross-border region.