Assessing the Sustainable Development of National Parks: A Multidimensional Index Approach for Poland in 2021 and 2024

This study assessed the level, structure, and changes in sustainable development across all 23 Polish national parks in 2021 and 2024. The National Park Sustainable Development Index (NPSDI; Polish acronym IZRPN) comprises 27 environmental, social, and economic and management indicators. Normative weights of 0.50–0.25–0.25 were applied, with separate annual normalisation for rankings and a common scale for 46 park–year observations. Financial amounts were expressed in 2021 prices. The analysis included sigma and beta convergence, k-means clustering, and sensitivity to weights and indicator selection, including a test addressing potential pandemic effects. Mean NPSDI increased from 0.4254 to 0.4265, but SD rose by 8.15% and CV by 7.89%. The baseline model provided no evidence of beta convergence for the overall index. E* and G* exhibited sigma and beta convergence, whereas S* exhibited sigma divergence. Ten-fold cross-validation identified five exploratory profiles. Fourteen parks (60.9%) retained their profile, while nine changed it. The findings should be interpreted as a diagnosis conditional on index construction, considered alongside the components, habitat conditions, and documentation of conservation activities.