Water Management and the Expansion and Demise of Angkor


Roland Fletcher 罗兰德·弗莱彻
University of Sydeney 悉尼大学


From the 5th century CE onwards the Khmer world began to create a variety of water management systems. Out of these developed the baray, a unique form of reservoir utilising water held entirely or substantially on the existing ground surface by substantial surrounding banks. While the sequence of development of the baray is still partially obscure it is clear that this form of water management and its associated networks of channels predates the late 9th century formation of Angkor and may predate it by several centuries. The significance of the period when the baray came into being is that this form of reservoir may have come into use in a relatively dry environmental water regime and then became profoundly significant first as a manager of erratic water supplies in the initial unstable climate changes of the Medieval Warm Period, becoming a stabiliser and risk management system for ensuring crop production from the 9th to the 13th century. The baray and their networks were therefore a pre-adaptation which secured crop supplies in an uncertain period and then supported increased aggregate crop yields in the peak warm phases of the Medieval Warm Period. The baray may therefore be usefully envisaged as a pre-adaptation which sustained the initial endurance and expansion of the Angkorian state and then stabilised its capital up to the 13th century. Some of the water infrastructure became immensely large. The massive material inertia that had been built into the baray and their canal networks then interacted with a new phase of extreme climatic instability in the 14th and 15th century. Planetary cooling in the late Medieval Warm Period produced monsoon intensities beyond the operational parameters of the network. In consequence the inertia of the network contributed to the disruption of a remarkably and uniquely elegant, simple and sophisticated water management system in Greater Angkor, leading to the demise of the capital in a period of great social and political transformation between the 13th and the 16th century CE.


Biographical Sketch

Dr. Roland Fletcher is professor of theoretical and world archaeology at the University of Sydney. Over the past thirty years Professor Roland Fletcher has developed a global and interdisciplinary perspective in archaeology, that integrates research, teaching and service. His fields of expertise are the theory and philosophy of archaeology, the study of settlement growth and decline and the analysis of large-scale cultural phenomena over time. In 1995 Fletcher published The Limits of Settlement Growth: a theoretical outline – an analysis of the past 15,000 years of settlement-growth and decline – with Cambridge University Press. He has an international reputation as a radical theorist and as the instigator of the Greater Angkor Project, which derives from his theoretical work and is part of a major research program in Cambodia. This program of research on Angkor has developed international collaborations for the University of Sydney and has enhanced its public profile through media presentations, such as the National Geographic International TV program ‘Lost City’. The Angkor research team also serves the intentional community through the applied research of the Living with Heritage Project at Angkor, in collaboration with the Cambodian government and UNESCO.