The Great Maya Droughts: Water, Life, and Death

Rating:
Summary: Dissapointing return to ecological determinism
Review: Although The Great Maya Droughts by Richardson Gill is a very impressive collection of information, it's not quite what I had expected. Given the title I had expected an archaeological account of recent finds and what they tell of the decline of Maya civilization. Instead the bulk of the book, eleven chapters of it, deals with a wide variety of scientific information having to do with a number of fields: physics, oceanography, complexity theory, meteorology, geology, hydrology, paleoclimatology, and volcanology among them. Not until the last two chapters of the book, and then mostly in summary form, does the author really discuss the archaeological data. For the average reader interested in the Maya and/or in general archaeology this might be a thirty dollar disappointment. Some of the material is rather complex, and although one might be able to work ones way through it on just the explanations the author gives of each topic, it would probably appeal more to those who already have at least some background in these areas. This having been said, though, I have to admit that I loved the book.

The author's primary goal is to introduce the theme of what he terms an energy failure as the cause of the Maya demise. To do this he approaches his topic as a physical scientist. Modern archaeology has come a long way since W. M. Flinders Petrie and A. Layard, and there is as much "hard" science involved in this discipline as digging in the sand. In fact with funds for excavations difficult to come by these days, there is probably far less digging in the sand going on now than there was in the past. Gill seems to be a model of the new archeologist/scientist. Steeped in what E. O. Wilson calls "consilience," the author calls upon data from a variety of fields to supply him with the building blocks he needs to reinforce his thesis.

At first I was a little skeptical of this type of approach, even though I know a fair amount about most of Dr. Gill's supporting subjects. By the time he got to a discussion of the shifting of the ecotomes in Europe during the Roman period (p. 16), I was totally hooked. I had just read a book covering the rise and fall of the Roman occupation in Gaul, and Gill's discussion of it in his work made perfect sense. With his treatment of human culture and its limitations in terms of thermodynamics and its evolution in terms of self organizing criticality, he had completely reeled me in. Like others, I had considered the decay of the Maya centers to be a "multifaceted" problem. Human culture and behavior being as complex as they are-or seem to be-a multidimensional answer to the problem seemed logical. As Gill presents it, however, there is nothing so logical-or so simple-as the destruction of the human animal by a lack of water. As he points out, a person can live for months without eating but only days without water.

The book is well worth the effort, even for those with limited knowledge of the included topics, as long as he/she has the desire to learn something new and isn't afraid of a little work. Furthermore, the bibliography is a mine of useful resources, both books and periodicals. Some are a little old, 1970-1980s, but many are more current. Of the books that I've read from the author's list: Per Bak's How Nature Works is fun, as is Sigurdsson's Melting the Earth. Jered Diamond's Guns, Germs and Steel is wonderful, a "must read" sort of book. Both Decker and Decker's Volcanoes and Bullard's Volcanoes of the Earth, though a little old, are interesting and easy to read. Of the journals American Scientist, Archaeology, Nature, Science, and Scientific American should be readily available in most college and urban public libraries. Those like Geology, The Holocene, Hydrobiologia, Hydrology, the Journal of Human Evolution, Journal of Paleoceanography, and Quaternary Research may be available in some university libraries or in their individual department libraries.

For THOSE WRITING PAPERS on archaeology, history, meteorology/climatology, anthropology, ecology, etc. this book would make an instructive source for "how-to-do-it with science." It would make an excellent source of quotes in support of your own themes, a good source for bibliographical material, and a good bibliographical entry for your own paper.

Not an easy book to get through. Certainly not for those who just want an overview of the Maya. Definitely worth it for those with a desire to learn.

Rating:
Summary: Definitely worth it for those with a desire to learn.
Review: Although The Great Maya Droughts by Richardson Gill is a very impressive collection of information, it's not quite what I had expected. Given the title I had expected an archaeological account of recent finds and what they tell of the decline of Maya civilization. Instead the bulk of the book, eleven chapters of it, deals with a wide variety of scientific information having to do with a number of fields: physics, oceanography, complexity theory, meteorology, geology, hydrology, paleoclimatology, and volcanology among them. Not until the last two chapters of the book, and then mostly in summary form, does the author really discuss the archaeological data. For the average reader interested in the Maya and/or in general archaeology this might be a thirty dollar disappointment. Some of the material is rather complex, and although one might be able to work ones way through it on just the explanations the author gives of each topic, it would probably appeal more to those who already have at least some background in these areas. This having been said, though, I have to admit that I loved the book.

The author's primary goal is to introduce the theme of what he terms an energy failure as the cause of the Maya demise. To do this he approaches his topic as a physical scientist. Modern archaeology has come a long way since W. M. Flinders Petrie and A. Layard, and there is as much "hard" science involved in this discipline as digging in the sand. In fact with funds for excavations difficult to come by these days, there is probably far less digging in the sand going on now than there was in the past. Gill seems to be a model of the new archeologist/scientist. Steeped in what E. O. Wilson calls "consilience," the author calls upon data from a variety of fields to supply him with the building blocks he needs to reinforce his thesis.

At first I was a little skeptical of this type of approach, even though I know a fair amount about most of Dr. Gill's supporting subjects. By the time he got to a discussion of the shifting of the ecotomes in Europe during the Roman period (p. 16), I was totally hooked. I had just read a book covering the rise and fall of the Roman occupation in Gaul, and Gill's discussion of it in his work made perfect sense. With his treatment of human culture and its limitations in terms of thermodynamics and its evolution in terms of self organizing criticality, he had completely reeled me in. Like others, I had considered the decay of the Maya centers to be a "multifaceted" problem. Human culture and behavior being as complex as they are-or seem to be-a multidimensional answer to the problem seemed logical. As Gill presents it, however, there is nothing so logical-or so simple-as the destruction of the human animal by a lack of water. As he points out, a person can live for months without eating but only days without water.

The book is well worth the effort, even for those with limited knowledge of the included topics, as long as he/she has the desire to learn something new and isn't afraid of a little work. Furthermore, the bibliography is a mine of useful resources, both books and periodicals. Some are a little old, 1970-1980s, but many are more current. Of the books that I've read from the author's list: Per Bak's How Nature Works is fun, as is Sigurdsson's Melting the Earth. Jered Diamond's Guns, Germs and Steel is wonderful, a "must read" sort of book. Both Decker and Decker's Volcanoes and Bullard's Volcanoes of the Earth, though a little old, are interesting and easy to read. Of the journals American Scientist, Archaeology, Nature, Science, and Scientific American should be readily available in most college and urban public libraries. Those like Geology, The Holocene, Hydrobiologia, Hydrology, the Journal of Human Evolution, Journal of Paleoceanography, and Quaternary Research may be available in some university libraries or in their individual department libraries.

For THOSE WRITING PAPERS on archaeology, history, meteorology/climatology, anthropology, ecology, etc. this book would make an instructive source for "how-to-do-it with science." It would make an excellent source of quotes in support of your own themes, a good source for bibliographical material, and a good bibliographical entry for your own paper.

Not an easy book to get through. Certainly not for those who just want an overview of the Maya. Definitely worth it for those with a desire to learn.

Rating:
Summary: Awesome Anthropologic Insight
Review: Dr. Gill has truly broken new ground with this startling theory on the demise of the Mayan Empire. Why no-one heretofore considered drought as the primary cause of the Mayan disappearance now seems remarkable. His premise debunks the previous and long-held concepts on the mysterious demise of these ancient people and literally re-writes a major chapter in the history of Mexico. Thank you, Dr. Gill for finally shedding light on this dark topic and providing a conclusive answer to what has long been a nebulous and even divisive black hole in the anthropologic annals of North America.

Rating:
Summary: Awesome Anthropologic Insight
Review: Dr. Gill has truly broken new ground with this startling theory on the demise of the Mayan Empire. Why no-one heretofore considered drought as the primary cause of the Mayan disappearance now seems remarkable. His premise debunks the previous and long-held concepts on the mysterious demise of these ancient people and literally re-writes a major chapter in the history of Mexico. Thank you, Dr. Gill for finally shedding light on this dark topic and providing a conclusive answer to what has long been a nebulous and even divisive black hole in the anthropologic annals of North America.

Rating:
Summary: Informative and very readable book about an important topic
Review: This book's central thesis is that Classical Maya civilization collapsed as a result of a drought in Mesoamerica extending throughout the 9th century AD. This particular drought was the local manifestation of Northern Hemisphere weather patterns that the author asserts have been repeated frequently over shorter time periods for thousands of years, even into this century, and which nearly always produce drought in Mesoamerica.

Once you accept the author's evidence for Mesoamerican droughts and their regularity, that evidence provides a parsimonious explanation for the end of Classical Maya civilization. After reading this book, I think many people will accept the evidence and the explanation.

More complex hypotheses, including overpopulation, warfare between Mayan city-states, external invasion, disease, over centralization, exhaustion of a stable environment, and peasant revolt are not needed to explain the collapse. This does not mean that such factors, if they existed, did not influence the course of the collapse, just that the collapse would have happened because of the drought whether or not other factors existed.

To support his thesis, which is clearly stated clearly at the beginning of the book, Dr. Gill takes the reader on a tour of a multitude of scientific disciplines. Each discipline studied adds information about the importance, frequency, possible causes and consequences of drought in Mesoamerican and on civilization and population trends throughout the world. Any one of these tours alone is worth the price of the book, since they are extremely well written and provide the foundation for further study on each topic covered.

In a chapter titled "Geology, Hydrology, and Water," the author describes the geology and hydrology of the Yucatan and the Maya highlands and the major drainage basins, and provides an extensive discussion of the water supply problem and how it was managed in the pre-Columbian period. The basic geology is the standard stuff: seasonal rainfall, permeable limestone, karstic drainage, deep underground fresh water usually inaccessible, except in the north through cenotes and along the east cost from freshwater lakes or lagoons. But, this chapter also explained how the Maya adapted to this environment. For example, the author describes natural surface depressions used as water reservoirs and known as aquadas. The Maya paved many of these small depressions and some were provided with chultunes, bell shaped chambers excavated below the aquada bottom to capture additional water when the aquada was filled. (A single chultun could hold 30,000 liters of water, enough to comfortably supply drinking and cooking water for twenty-five people for one year).

In fact, Mayan city-states and even smaller settlements were designed with water management a primary consideration, with central reservoirs, residential reservoirs, canals, and the terrain and pavement of the city itself all engineered to facilitate the collection and storage of water during the wet season. This was important, because, as explained in a chapter on "Paleoclimatology," small-scale (relative to the great final calamity) droughts were endemic to the Maya area as shown both by Maya water management strategies and more recent evidence from sediment recovered from the bottom of lakes. Records during the Spanish colonial period point to further famines on a regular basis after the conquest. In fact, during the colonial period, population looses from drought in the Yucatan ranged up to 30 or 40%.

In another chapter titled "Volcanoes and Weather" Dr. Gill argues that there is a strong correlation between the eruptions of large volcanoes around the world, and the worldwide weather patterns that lead to drought in Mesoamerica. This particular chapter not only provided evidence to support this correlation, but evidence that the volcanoes may have been a forcing mechanism for those weather patterns. Volcanoes and weather are a topic of some interest to me, and until I read this book, I had trouble finding a good introduction to the study of volcanoes, and to the relationship between volcanoes and weather. Now I have.

To save space and my own energy, I am not going to discuss the chapter on "Thermohaline Circulation." Except, I will say that that I learned enough in that one chapter on North Atlantic deep water formation and three dimensional ocean circulation models for all of the world's oceans to help me understand an article on the subject recently published in the journal Nature. I will also skip lightly over the early chapter titled "Self-Organization" which discusses, among other things, the overall flow of energy in a civilization, and the important roll of exporting entropy to the environment by a civilization to reduce the potentially disruptive entropy in the civilization. I will also skip lightly over the chapter titled "Famine and the Individual" which describes how famine can rapidly lead to the complete collapse of social norms and the massive disruption of "normal" energy flows in any civilization.

Probably the most important or challenging single assertion Dr. Gill makes is changing the timing of the collapse of Chichen Itza. Traditionally dated around 1150 AD, and cited as an example of the ability of some Maya cities to survive the Classical collapse, the author re-dates this event to the 9th century based partly on re-interpretation of inscribed calendar dates attributed to the period after the collapse. This particular assertion is probably one of the most controversial in the book and is critical to the author's basic thesis. I suspect that it will be the focus of considerable argument. In support of this claim, the author provides a new interpretation of the relationship between Chichen Itza and the Toltecs, which itself is probably worth a fair amount of discussion.

I strongly recommend this book to just about anyone with an analytical mind. If you are interested in the general flow of Maya civilization this book has a lot to offer. If you are generally interested in the interplay between climate and civilization, this book also has a lot to offer. If you are just somewhat interested in topics such as global meteorology, volcanoes, tree-ring records in Europe and America, or the debate between uniformitariansm and neocatastrophism in the early study of geology, you will still find useful information that is readily accessible.

Rating:
Summary: Informative and very readable book about an important topic
Review: This book's central thesis is that Classical Maya civilization collapsed as a result of a drought in Mesoamerica extending throughout the 9th century AD. This particular drought was the local manifestation of Northern Hemisphere weather patterns that the author asserts have been repeated frequently over shorter time periods for thousands of years, even into this century, and which nearly always produce drought in Mesoamerica.

Once you accept the author's evidence for Mesoamerican droughts and their regularity, that evidence provides a parsimonious explanation for the end of Classical Maya civilization. After reading this book, I think many people will accept the evidence and the explanation.

More complex hypotheses, including overpopulation, warfare between Mayan city-states, external invasion, disease, over centralization, exhaustion of a stable environment, and peasant revolt are not needed to explain the collapse. This does not mean that such factors, if they existed, did not influence the course of the collapse, just that the collapse would have happened because of the drought whether or not other factors existed.

To support his thesis, which is clearly stated clearly at the beginning of the book, Dr. Gill takes the reader on a tour of a multitude of scientific disciplines. Each discipline studied adds information about the importance, frequency, possible causes and consequences of drought in Mesoamerican and on civilization and population trends throughout the world. Any one of these tours alone is worth the price of the book, since they are extremely well written and provide the foundation for further study on each topic covered.

In a chapter titled "Geology, Hydrology, and Water," the author describes the geology and hydrology of the Yucatan and the Maya highlands and the major drainage basins, and provides an extensive discussion of the water supply problem and how it was managed in the pre-Columbian period. The basic geology is the standard stuff: seasonal rainfall, permeable limestone, karstic drainage, deep underground fresh water usually inaccessible, except in the north through cenotes and along the east cost from freshwater lakes or lagoons. But, this chapter also explained how the Maya adapted to this environment. For example, the author describes natural surface depressions used as water reservoirs and known as aquadas. The Maya paved many of these small depressions and some were provided with chultunes, bell shaped chambers excavated below the aquada bottom to capture additional water when the aquada was filled. (A single chultun could hold 30,000 liters of water, enough to comfortably supply drinking and cooking water for twenty-five people for one year).

In fact, Mayan city-states and even smaller settlements were designed with water management a primary consideration, with central reservoirs, residential reservoirs, canals, and the terrain and pavement of the city itself all engineered to facilitate the collection and storage of water during the wet season. This was important, because, as explained in a chapter on "Paleoclimatology," small-scale (relative to the great final calamity) droughts were endemic to the Maya area as shown both by Maya water management strategies and more recent evidence from sediment recovered from the bottom of lakes. Records during the Spanish colonial period point to further famines on a regular basis after the conquest. In fact, during the colonial period, population looses from drought in the Yucatan ranged up to 30 or 40%.

In another chapter titled "Volcanoes and Weather" Dr. Gill argues that there is a strong correlation between the eruptions of large volcanoes around the world, and the worldwide weather patterns that lead to drought in Mesoamerica. This particular chapter not only provided evidence to support this correlation, but evidence that the volcanoes may have been a forcing mechanism for those weather patterns. Volcanoes and weather are a topic of some interest to me, and until I read this book, I had trouble finding a good introduction to the study of volcanoes, and to the relationship between volcanoes and weather. Now I have.

To save space and my own energy, I am not going to discuss the chapter on "Thermohaline Circulation." Except, I will say that that I learned enough in that one chapter on North Atlantic deep water formation and three dimensional ocean circulation models for all of the world's oceans to help me understand an article on the subject recently published in the journal Nature. I will also skip lightly over the early chapter titled "Self-Organization" which discusses, among other things, the overall flow of energy in a civilization, and the important roll of exporting entropy to the environment by a civilization to reduce the potentially disruptive entropy in the civilization. I will also skip lightly over the chapter titled "Famine and the Individual" which describes how famine can rapidly lead to the complete collapse of social norms and the massive disruption of "normal" energy flows in any civilization.

Probably the most important or challenging single assertion Dr. Gill makes is changing the timing of the collapse of Chichen Itza. Traditionally dated around 1150 AD, and cited as an example of the ability of some Maya cities to survive the Classical collapse, the author re-dates this event to the 9th century based partly on re-interpretation of inscribed calendar dates attributed to the period after the collapse. This particular assertion is probably one of the most controversial in the book and is critical to the author's basic thesis. I suspect that it will be the focus of considerable argument. In support of this claim, the author provides a new interpretation of the relationship between Chichen Itza and the Toltecs, which itself is probably worth a fair amount of discussion.

I strongly recommend this book to just about anyone with an analytical mind. If you are interested in the general flow of Maya civilization this book has a lot to offer. If you are generally interested in the interplay between climate and civilization, this book also has a lot to offer. If you are just somewhat interested in topics such as global meteorology, volcanoes, tree-ring records in Europe and America, or the debate between uniformitariansm and neocatastrophism in the early study of geology, you will still find useful information that is readily accessible.