Scales of transformations—Modelling settlement and land-use dynamics in late antique and early medieval Basel, Switzerland

Abstract

Multicomponent environmental models have increasingly found their way into archaeological research. Mostly, these models aim to understand human patterns as a result of past climatic and environmental conditions over long-term periods. However, major limitations are the low spatial and temporal resolution of the environmental data, and hence the rather static model output. Particular challenges are thus the number of chosen variables, the comprehensiveness of the explanatory parameters, and the integration of socio-cultural decision-making into the model. Here, we present a novel approach to generate annually resolved landcover variability using a broad variety of climatic, geological, hydrological, topographical, and dendrochronological data composites (Palmer Drought Severity Index (PDSI)). We analyze land-use and settlement capacity and vulnerability to estimate the socio-cultural transformation processes at Basel (Switzerland) during the Late Antiquity and the Early Middle Ages. Our results highlight the potential of the PDSI to predict local river run-off behavior from catchment analyses. The model enables to trace landcover as well as socio-cultural response to climatic variability and subsequent adaptation to trends in environmental vulnerability. This approach further helps to understand population dynamics in the periphery of the Roman administrative boundaries and to revise traditional archaeological narratives of large-scale population replacements during the so-called Migration Period.

Bioarchaeological analyses reveal long-lasting continuity at the periphery of the Late Antique Roman Empire

“…Most of the highly suitable sites are located within a 1 km distance of the settlement, which aligns with the theory underlying the activity spheres of subsistence farming of this article. 59 Following the expectations of the given hypothesis, the land-use suitability decreases toward the other side of the river Wiese. Crop production on both sides of the river cannot be ruled out.…”

“…A qualitative environmental analysis of the Waisenhaus graveyard catchment was carried out to predict the potential location of the corresponding Late Antique settlement, the associated croplands, and pastures. 59 The model was used to assess if the Sr isotope baseline suggested by Brönnimann and colleagues for the Iron Age site Basel-Gasfabrik, located 1.8 km away to the north-west ( Figure 3 ), could equally be used for this study. 57 We used various environmental parameters to identify suitable settlement spots based on geological and pedological attributes, groundwater level anomalies, landscape accessibility, and permeability, as well as the potential premodern hydrologic system in a 1.5 km distance around the site.…”

“…The variables were merged using a focal approach with high values equaling high suitability and low values representing low suitability. 59 An accumulated friction surface was calculated to integrate the river channels, measuring the permeability of a given area based on topographic roughness. Eventually, a potential movement expenditure derived from the centre of the site at Basel Waisenhaus.…”