A reconstruction of the occupation layer of archaeological sites according to a statistical analysis of multispectral imaging

Abstract

In the modern era and especially in the 20th century, the territory with most of the archaeological sites in central Russia and the Urals was used as agricultural land. The history of long-term studies of medieval Finno-Ugric settlements (Cis-Urals) makes it possible to distinguish segments of an occupation layer in various states of preservation: superficially disrupted, replaced and transported. Superficially disrupted and replaced layers are found at the settlement site and are believed to be residential and economic areas​​. The transported layer is mainly transported to the slopes of the terraces to which the sites of the Chepetskaya culture are assigned. Therefore, it is necessary to study not only the site of the settlement itself but also the adjacent territory. To reconstruct the boundaries and structure of medieval settlements, a new methodological approach has been proposed. Initially, a statistical analysis of multispectral aerial photography data was carried out: the calculation of Haralick's textural features; the reduction in the number of features by principal component analysis and the segmentation of images based on the obtained features using the k-means method. This makes it possible to divide the settlement site and the surrounding area into areas with fundamentally different vegetation intensities. A comparison with the geophysical, soil and archaeological survey data allows the interpretation of the identified areas. The research was carried out at the settlement of Kushman-3 (9th–13th centuries AD). Two lines of defensive structures, which are not manifested in the relief, were identified; the structural parts of the settlement were determined and an interpretation of the way they were used in the Middle Ages was proposed. As a result of the application of the new statistical algorithm, the locations of occupation layer segments in different states of preservation were determined, and the boundaries of the Kushman-3 settlement were substantiated.