Origin, mutations and dynamics in Southeastern Arabia oases: Soil/water availability and management for the last 5 millennia – OASIWAT

The project OASIWAT aims to understand the social and environmental factors that have contributed to the development, mutation and durability of oases in Southeast Arabia since the 3rd mil. BC until today. Oases are precious man-made constructions, intensively cultivated and irrigated, that have evolved under a fragile and fluctuating socio-economic, technological, demographic and climatic equilibrium.

The emergence and evolution of oases in Southeast Arabia are closely tied to a socio-economic system structured around the exploitation, transformation and export of copper ingots from the Hajar mountain chain, covering most of the United Arab Emirates and northern Oman, to the Near East, Africa and the Indian peninsula. Archaeological data have provided information on cycles of occupation and abandonment of both villages and oases (sedentarisation versus bedoinisation) since the Bronze Age (eg. land conquest: Bronze Age (3rd mil. BC), Iron Age II (1300-600 BC), Late Islamic Period (14-17th c. AD); abandonment: End of the Bronze Age (2000-1300 BC), Iron Age III (600-300 BC)). However, data are patchy for intermediate periods (late PIR/Sassanid/Early Islamic (300 BC-1400 AD)) as well as on the dynamics of the oases themselves and their agrosystem. This is partly due to the fact that past oases are traditionally perceived as retroprojections of current ones and their study hampered by the denial of their diachronic dimension. Moreover, archaeological data are often directly connected to climate change. Unfortunately, there is a substantial paucity of environmental records for much of Arabia beyond ca. 4,200 years BP. Research on the short-term and high amplitude climatic shifts has mainly focussed on early and mid-Holocene periods. As a consequence, the long-term correlation between climate, resource availability and management, settlement pattern and socio-economic systems remains unclear.

The project OASIWAT proposes an innovative reconstruction of these landscapes based on a systematic diachronic and integrated study of oasian agro-hydrosystems, considered as adaptative answers to demographic, hydro-and morpho-sedimentary constraints. Two tasks have been defined:
1- Estimate the evolution of natural resources availability (water and soil) by building a regional geomorphic, paleohydrological and climatic framework for the last 5 millennia. This framework will be established through the multiproxy analyses of a range of palaeoenvironmental archives (eolian, fluvial, and coastal) at the scale of the watersheds, and solid OSL and 14C dating.
2- Understand the emergence and evolution of the oasian hydro-agrosystem through a-the creation of a 3D model of past and current oases, b- the innovative combination of interdisciplinary methods in the field and in the laboratory (geoarchaeology, agronomy, archaeology, (paleo)pedology - micromorphology, geochemistry, ethnopedology, paleobotany), c-the creation of a precise chronological framework based on14C and OSL.

The project will focus on 3 oases in the Hajar Mountains (Masafi and the Unesco site of Al Ain in the United Arab Emirates, and Rustaq in Oman), selected for their unique geographical location (in terms of resources and climate), the presence of well-preserved deposits and the possibility of creating solid references. Their study will allow for a better understanding of human, economic and social adaptations to hydro-climatic constraints. The creation of diachronic technological-climatic landscape models will contribute to deconstructing the fixed “oasian model” while fuelling the debate on the balanced management of these fragilized and precious spaces.