20. Mixing geoarchaeology, geohistory and ethnology to reconstruct landscape changes on the longue durée

This chapter uses a combination of quantitative and qualitative social and biophysical methods to characterise socio-environmental changes over the Holocene. Based on a regressive approach, this work gathers data with varying granularity, precision and resolution from sources that are as different as radiocarbon dating, sediment analyses, travellers' accounts, aerial photographs and interviews with contemporary populations. Borrowing methods from geomorphology, palaeoenvironments, palaeoclimatology and geohistory, ethnology, and human geography leads to a holistic and systemic approach, considering all aspects of an issue to leave as few grey areas as possible. There are challenges to this approach, the biggest being to assemble diverse data and produce a coherent discourse on environmental history. To illustrate the “recipe” of this approach, its replicability and limits, the chapter focuses on two study sites (Ethiopia and Greece), while also pointing to some particularities of sites in Egypt, Sudan and Oman.