Decaying villages in the centre of Europe with no population decline: Long-term analysis using historical aerial images and remote sensing data

Agricultural land abandonment and depopulation of rural areas are a problem observed in numerous regions of the world, especially in Europe. Effectively counteracting this phenomenon requires the development of tools adapted to its nature in a given area as well as the origin and dynamics of observed changes. The article presents a study on the dynamics of land abandonment in central Poland, which has resulted in the complete abandonment of land cultivation of an area of hundreds of square kilometres. Historical stereometric aerial photographs from 1973 and the results of ALS measurements taken in 2012 were used in the study. The historical data was used to generate point data clouds representing the three-dimensional, historical structure of vegetation height in a specific year, with an accuracy similar to that of contemporary ALS measurements. The results obtained were quite surprising because, unlike many other studies of this issue, no intensive depopulation was found, and the change in the age structure, although noticeable, does not differ significantly from the changes observed in the entire population of Poland during the period in question. This approach allows for a very accurate assessment of changes in land use, in particular the process of the abandonment of land use, combined with secondary forest succession and self-reforestation processes. Such an analysis may cover a period of several decades and its results allow a precise diagnosis of the duration and dynamics of abandonment.