Quantifying Water and Tillage Soil Erosion Risk to the Neolithic Settlement Site of Bylany (Czech Republic)

Abstract

This study assesses the threat of soil erosion to the unique Neolithic settlement site of Bylany. Since the 1950s, it has been explored using traditional archaeological methods and, more recently, non-destructive techniques like aerial prospection and geophysics. The archaeo-geophysical survey using magnetometry revealed more frequent fragmented linear magnetic anomalies and decreased magnetic intensities, indicating some differences in the sunken archaeological features. We hypothesised that these differences result from soil erosion. To test this, we conducted field surveys at well-documented archaeological sites, comparing changes in the depths of sunken features. Additionally, erosion modelling was used to reveal whether the field survey results align with the present modelled potential soil erosion. Findings indicate that this unique settlement area is threatened by water and tillage soil erosion to such an extent that some of the sunken features are being destroyed. The rate of soil erosion estimated by the field survey is between 0.6 and 18 mm.year⁻¹; the modelled total soil erosion for the resurveyed features was up to 3.6 mm.year⁻¹ (50.7 t ha⁻¹ year⁻¹). Modelling also suggested even higher erosion on a slope where a smaller rondel was detected by a geophysical survey in 2019 but remains unexcavated. The results highlight the urgent need for conservation efforts to protect this unique archaeological settlement site featuring three rondels on the same land from further degradation. This study thus provides a compelling case of unanticipated soil thickness reduction, as was suggested by geophysical surveys and verified by excavation data.