The End of the “Green Oasis”: Chronological Bayesian Modeling of Human and Environmental Dynamics in the Bahariya Area (Egyptian Sahara) from Pharaonic Third Intermediate Period to Medieval Times

Abstract

After the sharp transition to aridity that followed the “Green Sahara” episode 5500 years ago, human settlements took refuge in Egyptian oases, which have to varying extents been “Green Oases” for centuries. In that period, synchronous with the beginning of historical times, the desert’s aridity is generally regarded as broadly comparable to the current period. Natural and anthropogenic deposits studied during 13 excavation campaigns in Bahariya Oasis (Egyptian Desert) suggest that a fairly clear transition from a relatively green environment to much more arid landscapes occurred in the first millennia BCE and CE. This article aims at establishing the chronology of human occupations and environmental change within this period, by combining archaeological and radiocarbon data, using Bayesian modeling. It reveals that the drying up of the environment experienced by desert farmers occurred at some point between the reigns of Antoninus Pius and Caracalla (2nd–3rd century CE). The accuracy of the produced chronological models made it possible to highlight synchronisms between the end of this “Green Oasis” phase and comparable aridification phenomena on regional and interregional scales. Similar degradation processes on remote sites inside the Roman Empire might be explained by globalized anthropogenic agencies overlapping with a broader climatic drying.

Echoes of the Past: Unveiling the Kharga Oasis’ Cultural Heritage and Climate Vulnerability through Millennia

“…In recent years, there have been several scholarly investigations that have concentrated on the restoration of paleoclimatic variations in the Western Desert of Egypt [1,1,7,25,34,38,39,41,42,[44][45][46]. The aforementioned researches have employed various metrics such as radiocarbon dating of human habitation, geomorphological scrutiny encompassing the detection of lacustrine deposits, and the scrutiny of plant macro remains to reconstruct the crucial ecological circumstances that support human sustenance.…”

“…The aforementioned researches have employed various metrics such as radiocarbon dating of human habitation, geomorphological scrutiny encompassing the detection of lacustrine deposits, and the scrutiny of plant macro remains to reconstruct the crucial ecological circumstances that support human sustenance. In this study, rock art evidence was employed to examine the effects of paleoclimate fluctuations on the Kharga Oasis [7,11,47,48].…”

“…Dating back 12,000 years, the Kharga Oasis provides abundant evidence of human settlements [3][4][5]. The Kharga Oasis has experienced a substantial concentration of population and commercial activity since 10,500 B.C., continuing into the Pharaonic period [6][7][8]. However, the northern parts of the Kharga Oasis were likely completely abandoned due to paleoclimatic changes, though population declines may have occurred during certain periods.…”

The IPCC: A Primer for Archaeologists

“…This is a tall order for archaeology, but we should not give up hope. We are constantly seeing breakthroughs in chronology building from development of new techniques (Casanova et al 2020) and better methods for pruning temporal uncertainty given multiple sources of chronological information (Colin et al 2020). Agroecosystem models incorporating local climate signals are increasingly available in areas beyond the U.S. Southwest (e.g., Contreras et al 2019).…”