Evaluating Erosional Impacts on Open-Air Archaeological Sites along the Doring River, South Africa: Methods and Implications for Research Prioritization

Open-air sites in arid and semi-arid landscapes are often subject to prolonged periods of exposure and episodes of erosion that can lead to the redistribution of artefacts and the loss of behaviorally significant spatial information. This is true along the Doring River, South Africa, where archaeologically rich sediment stacks with records exceeding 200,000 years are undergoing rapid erosion in response to modern climatic conditions and land use practices. This paper evaluates the impacts of past and future erosion on the disaggregation of artefacts from these open-air sites and the resulting loss of stratigraphic context and behaviorally significant spatial information. We use low elevation aerial images of the Klein Hoek 1 locality captured by an unmanned aerial vehicle (UAV) to develop a high-resolution local digital terrain model (DTM), which we use to model surface flow paths and quantify the potential for future sediment loss using the Revised Universal Soil Loss Equation (RUSLE). We compare the results of these analyses to the distribution of artefacts of different ages to assess artefact dispersion and to guide future research priorities at the locality. We find that some artefact clusters retain significant spatial integrity, whereas others are dispersed and likely out of primary context. The results also indicate that the geomorphic stability of a large part of Klein Hoek 1 has been compromised by erosion, with limited prospects for long-term survival given the present climate and land use practices.