How Climatic Changes Toppled The Ancient Megacity Of Angkor

By Roni Dengler | October 17, 2018 3:56 pm

(Credit: Intarapong/Shutterstock)

Angkor, one of the most significant archaeological sites in Southeast Asia, was a thriving metropolis at the center of the Khmer Empire in the 13th century. Then its inhabitants suddenly left town. Now, researchers find abrupt climatic changes and vulnerable infrastructure led to the city’s demise. It’s a cautionary tale for modern cities, many of which are already feeling the stress of climate change.

Monumental Megacity

Once a vast, urban hub, Angkor was the capitol city of a kingdom that stretched from the tip of the Indochinese Peninsula to modern Yunnan Province in China and from Vietnam to the Bay of Bengal. By the 13th century, the city itself covered at least 100 square kilometers. Over 600 years, ruling kings added to the metropolis, building majestic monuments including Angkor Wat, a Buddhist temple that is a central tourist attraction near the modern-day city of Siem Reap in Cambodia. Historical accounts say Angkor was a bustling megacity into the late 13th century. But, the next available record from a few hundred years later indicates the city was abandoned, the jungle encroaching on its temples.

Experts debate what led to the city’s collapse. Some believe the Siamese overthrew Angkor; others say religious conversions and civil wars upset the social balance. Yet, recent evidence from remote mapping of the region suggested the city’s infrastructure played a role. During its reign, Angkor established an extensive system of waterways. The complex network of canals, moats and reservoirs to capture, store and distribute surface water likely provided water for agriculture and controlled flooding from seasonal rains. But in the late 14th century, the area experienced summer monsoons so intense they damaged the water management network.

Vulnerable Infrastructure

Daniel Penny, a geoscientist and anthropologist at the University of Sydney in Australia, and colleagues wanted to find out whether the atypical rainfall tipped the city’s infrastructure past its capacity and led to the city’s downfall. So the researchers built a model of Angkor’s water infrastructure network based on comprehensive archeological maps. Then they subjected the simulated waterways to flooding. The model revealed large floods could quickly destabilize the city’s water system thanks to feedback from erosion and sedimentation, the researchers report today in the journal Science Advances. The results match up with physical evidence of the system and rainfall records over Southeast Asia from the 14th century.

The researchers say the city’s infrastructure — developed over successive construction efforts built on top of and dependent on each other—was vulnerable to climatic changes. That breakdown contributed to the city’s collapse, and it’s a lesson for urban architects today, they say. Infrastructure designed to be modular and redundant would help to minimize disruptions of basic services and ease repair after damage occurs, something only more likely as climate change progresses.

CATEGORIZED UNDER: Environment, Living World, top posts
  • Dodgy Geezer

    These are models based on the archaeological remains and records. But the one thing that is missing is actual evidence of the sedimentation.

    Why is this? If the study had predicted that sedimentation would be found and field work confirmed this that that would comprise strong supporting evidence for the hypothesis. As it is, all we have is a model finding – and we now know that models can be used to support a very wide variety of theories – including some which real world evidence shows to be downright wrong…

  • seth korion

    Karl Popper, The Logic of Scientific Discovery:

    “The first of these model languages lacks even the means of expressing identity. As a consequence, it cannot express an equation: it does not contain even the most primitive arithmetic. The second model language works only as long as we do not add to it the means of proving the usual theorems of arithmetic—for example, Euclid’s theorem that there is no greatest prime number, or even the principle that every number has a successor. In the third model language—the most elaborate and famous of all—mathematics can again not be formulated; and, what is still more interesting, there are no measurable properties expressible in it. For these reasons, and for many others, the three model languages are too poor to be of use to any science. They are also, of course, essentially poorer than ordinary languages, including even the most primitive ones.” xxiv

    “Every system of concepts which satisfies a system of axioms can be called a model of that system of axioms. The interpretation of an axiomatic system as a system of (conventions or) implicit definitions can also be expressed by saying that it amounts to the decision: only models may be admitted as substitutes. But if a model is substituted then the result will be a system of analytic statements (since it will be true by convention). An axiomatic system interpreted in this way cannot therefore be regarded as a system of empirical or scientific hypotheses (in our sense) since it cannot be refuted by the falsification of its consequences; for these too must be analytic.” p53

    • csjordan

      Kind of tired of people giving these folks, who did a lot of work to present this theory, grief because they can’t take a transporter back to 13th century Cambodia and have to be actual scientists instead(with all that risk of being proved wrong).

      Ease up people! We know this is just a model. If you have problems with how they did the model then just spit it out!

      I’m sure lots of people will, as is supposed to be with scientific theories, look deeply at it and try to find flaws.

      It’s how the system works, dawg!

      But you guys aren’t doing that: you are criticizing anthropology(!?!) and modeling as a form of science.

      They modeled it. Is it accurate or not(and why)?

      And please, somebody tell me what anthropology has to do with whether a heavy rain washes out a dam or not?

      • seth korion

        “If I tell you your half attention will only half learn.”—Ethan A Hawley to his teenage son; The Winter of Our Discontent, Steinbeck

        Karl Popper was explicit. So was Geezer.

        Download Popper’s The Logic of Scientific Discovery and read it until you get it.

        • Swami_Binkinanda

          The inept sophists’ children’s book of bible stories. “read it until you get it” is the same argument for Scientology, Christian Science, and evangelism.
          Popper is not a god and his philosophy of science was not concocted to solve social historic and prehistoric problems. Foolish religiosity is not something Popper would have respected or demanded of others. How your methodology solves the problems you face is the real test. If it requires a snotty appeal to authority, then it probably fails.

          • seth korion

            No Popper was not a god, and no the reference to him was not an appeal to authority.

            It was specifically about his discussion concerning models and the fact they are not science. It was intended to be an introduction to the fallacies of scientific thinking. Something for csjordan to think about.

            And don’t evade the subject, which was the efficacy of the Angkor model, nothing else. Everything you’re raving about in your assumptions is not relevant to what I said.

  • Uncle Al

    Anthropology is discovering a muddy headless Ken doll, then pontificating about a culture worshiping Turkish (as opposed to Italian) eunuchs.

    • csjordan

      See above: scientific method.

      If you have a better way to figure things out, please enlighten us.


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