Abstract

Angkor, the capital of the Khmer Empire between the 9^th and the 14^th century, was a giant low-density urban complex covering about a thousand square kilometres – the most extensive city in the world until the later 19^th century. The population was about 750,000. The city contained hundreds of shrines including the 15 or so larger temples for which it is justly famous.  The large temples required immense maintenance staff. For exampl e, the Ta Prohm, one of the ten largest, had a staff of 12640 people and a support population of 66625 people. The population of Angkor depended on the vast infrastructure of the urban water management network to minimise the risks of seasonal variation in rainfall. The tropical forest had been removed and replaced by bunded rice fields and an anthropogenic woodland around the houses. By the 14^th century parts of the urban network were over 500 years old. In the 13^th century the transition from the Medieval Warm Phase to the Little Ice Age had commenced leading to severe climatic instability for more than a century.  Mega-monsoons were interspersed with severe droughts. The water load of the mega-monsoons tore out the main canal across Angkor and caused serious erosion in Central Angkor. The water management network was disrupted and the urban population’s protection against drought was broken. Between the 14^th and the16th century Angkor was largely abandoned and the urban heartland of the Khmer Empire reverted to forest and villages. The impact of severe climate change on the combination of low-density urbanism, extensive landscape clearance and dependence on massive infrastructure has some potential significance for the present day.

The lecture will be followed by a wine reception.