Karstic Aquifers and Climate Refugia: A Preliminary Outline History of Water-Management Strategy in Bronze and Iron Age Southeast Arabia

Abstract

This paper attempts to set out a preliminary narrative of changing water exploitation and settlement in Southeast Arabia from the Umm an-Nar period to the Iron Age, with a particular focus on the 4.2ka event. It argues for long-term cultural and adaptive trends that are only now becoming apparent and are relevant to understanding local adaptation strategies to climatic events such as the 4.2ka event. In setting out this narrative, we also aim to show the value of Southeast Arabian data to regional discussions relating to human adaptation to climate change. We argue that lower ground water availability related to aquifer structures would have been a problem for Bronze Age (Umm an-Nar) communities, in particular those living in Central Oman around the Hajar Mountains and would have affected settlement viability in certain climatic conditions, leading to decline in the number and size of settlements after c. 2000BC. We suggest that late Umm an-Nar (2200–2000BC) settlement and agricultural activity over-extended in this area, a development paralleled in Harappan and Mesopotamian communities. These changes would have affected already ancient traditions, for example in relation to the communal ritual monuments. By contrast, for the Northern Emirates karstic aquifers were a crucial factor supporting settlement continuity after the 4.2ka event, in particular in the western coastal areas of Ras al-Khaimah and the area around Dibba on the east coast. It is argued that the distribution of these aquifers is key to understanding the cultural and economic changes associated with the ensuing Wadi Suq period (2000–1600BC). Other processes strengthened the pattern, such as changing interregional exchange patterns and associated overland and maritime routes. By the Iron Age (starting c 1300 BC), it appears that rainfall patterns changed again and settlement density in Central Oman began once again to exceed that of the Northern Emirates. We suggest that this is at least partly linked to the resilience of local communities in dealing with another climate event (3.2ka event) that potentially necessitated the management of climatic patterns that may have included periods of higher and lower rainfall including irregular flooding. Whilst some of the ideas set out here are still quite speculative, they are set out in the belief that further understanding of these changing patterns is crucial for our understanding of long-term adaptation to climate change in this region.

Keywords

• climate change
• aquifers
• south east arabia
• settlement change
• local resilience
• 4.2ka event