Water supply and sanitation in El Salvador

Transcription

Hi, I’m John Green and this is Crashcourse World History and today we’re going to talk about our old friend, the rise and fall of civilizations. And we're going to look at it through the lens of War! No, just kidding, resources. Really Mr. Green? Haven’t we MINED that topic enough? JMG: I see what you did there, Me From the Past, and I do like your puns. I don’t like much about you, but I like puns. But we do talk a lot about resources and environmental issues in this series, because, you know, uh, they’re important. you know, because we just have the one planet on which to have history, but today we’re going to switch things up by looking at time periods and regions, and a resource that we haven’t examined before. Rather than like food or animals or precious metals, today we’re going to talk about water, without which we wouldn’t have food or animals. And precious metals would be of very limited use, because we also wouldn’t have humans. And we’re going to travel to the classical Mayan and Khmer civilizations in Central America and South East Asia respectively. Well, we’re not actually going to travel there because we don’t have the budget for a time machine. So, not only would we die of thirst without water, we also need to have enough of it around to raise plants and animals, because, you know, that’s how we eat. Some places get enough rain to support agriculture, but the vast majority don’t, which is why irrigation is often a requirement for building cities and stuff. And then there are places on Earth that get too much water, often because seasonal rains cause rivers to flood. And in these places people need to build dams and levees to control the flooding and also to channel the extra water to places where it can be useful. These kinds of projects, like, reservoirs, wells and cisterns are all examples of water control, or what some people call “hydraulic engineering.” hydraulic engineering was necessary, and people have been remarkably ingenious when it comes to agriculture. So, we know that we need agriculture for cities, and what we call civilization, and in most places, some form of hydraulic engineering is necessary for agriculture, which means it’s necessary for everything that comes after. But water isn’t only for drinking and eating. Like, those of you who remember the Indus Valley episode recall that Mohenjo Daro featured a giant basin that we called the Great Bath, which historians believe had a ritual function. And even if it didn’t, bathing is important for keeping clean. You know, one of the things that we use water for is sanitation and hygiene. And in dry regions the ability to control water can be symbolic of wealth and power. I mean, look at Las Vegas. Why do you think there’s this fountain at the Bellagio hotel in Las Vegas in the middle of a desert? It’s a way of bragging. Look at all of the money we took from you at our casino. But, quite a while before that, the Mayans managed to build a remarkably complex culture in one of the world’s least hospitable regions, and they couldn’t have done it without water management. Mayan culture reached its peak between 250 and 900 CE, and it was centered in the Yucatan peninsula in what is now Mexico and reached into parts of what today are Guatemala, Honduras and El Salvador. The Mayans developed complex mathematics primarily used to create calendars that do NOT predict the end of the world. And they also had a writing system, which described their religion and their rulers, the Holy Lords, who were both political and religious leaders. When the Mayan civilization collapsed it was not because all the people died out – you can still find many a Mayan today – but because these Holy Lords lost their authority, At which point the Mayans stopped living in their massive temple complexes. But we should start at the beginning. Let’s go to the Thought Bubble. So as we mentioned before, the Yucatan is not an ideal place to build a civilization. Most of it is a karst plain with a bedrock of limestone. The soils are poor and the water table is too low to excavate wells without modern digging equipment. There aren’t many rivers and rainfall is highly seasonal, with torrential downpours during the unpredictable wet season and a long dry season. Much of Mayan agriculture was small scale, but it produced enough surplus to provide tribute for the Holy Lords. Archeological records show that by 1000 BCE people were digging ditches to drain swamps, and settlements were built in such a way to capture rain runoff. Tikal is one of the major Mayan centers that has over 3000 structures in its 16 square kilometer footprint. It took generations to build and it “entirely lacked a natural supply of water: no springs, rivers, or lakes in its immediate vicinity.” So to supply water for the estimated 60,000 people who lived and worked there they created reservoirs. But, a diverse environment meant diverse solutions to water issues. At Edzna they built cisterns to capture rainwater and canals to connect reservoirs to the central ceremonial complex. They were able to collect 2 million cubic meters of water from runoff. At Palenque, in the lowlands of Chiapas, Mexico, they built “aqueducts, dams, channels, drains and a bridge,” to control flooding caused by streams that fed the city. In all these places, water management required a lot of labor. How much of this was cooperative and how much was coerced, we can’t really say. Thanks, Thought Bubble. Another thing we can’t really know for sure is the role that water played in Mayan politics and religion, but we can make some educated guesses. Mayan art features a lot of water motifs, so much so that one scholar has described the Maya as “having a fascination with aquatic iconography.” It is also possible that the authority of the Holy Lords rested largely on their ability to control water. Anthropologist Lisa Lucero suggests that the Holy Lords controlled the reservoirs and distributed water to the people during the dry season in return for tribute in the form of food and labor. If this was true, it was a dangerous game for the Holy Lords, because basing your claim to power on an ability to bring rain can get you in trouble when a drought comes along. And, of course, that’s what happened. Mexico can be particularly vulnerable to drought related to our old historical actor friend El Nino. And scientists, oh it’s time for the Open Letter. But first let’s see what’s in the globe today. Uh-oh, it is a warm swirl of water off the coast of South America. An Open Letter to El Nino. Hey El Nino. Right, so scientists, using tree rings and ice cores have figured out that the Yucatan did suffer a series of droughts that correspond to the decline of Maya power. As impressive as the Maya were, in some ways they pale in comparison to the Khmer culture that flourished between 802 and 1327 CE in what is now Cambodia. The Khmer are best known for building the temples at Angkor, most famously Angkor Wat the largest religious building ever constructed. But almost as impressive were the reservoirs surrounding the temple complex, especially the West Baray which is 8 kilometers long and 2 kilometers wide and at one point held more than 48 million cubic meters of water. The water issues in Cambodia are different from those found in Mexico, but the amount of labor and care that went into dealing with them is the same. And like the use of water in Mayan complexes, the function of the barays is not fully known. On a functional level, it’s not clear if they were used for irrigation during the dry season or flood control during the monsoon. And it’s also possible that they served a religious function, being “an attempt to recreate heaven on earth.” We don’t know a whole lot about the people who lived at Angkor except what we can glean from a few of the relief carvings and a Chinese written account from the 13th century, but most of them were peasant rice farmers. Angkor Wat was built by king Suryavarman II in the 12th century, so it was a relatively late addition, and came after the construction of the West Baray a century earlier. Modern archaeological techniques, including imaging from space have revealed that the barays and moats surrounding the temples, most of which are gone today, were linked by a series of channels. What they don’t reveal is their function. Bernard Philippe Groslier, who characterized Angkor as a “hydraulic city,” thought that the barays were built to catch monsoon water that would be used to irrigate rice during the dry season. He was influenced by Wittfogel and assumed that a great deal of centralized control was needed to provide food and water for a population that he estimated at 1.9 million people. Sounds like a good theory, but it was challenged by anthropologist W.J. van Liere who argued that religious considerations probably determined the layout of the barays because they were not well situated for irrigation. Probably the best answer is that the hydraulic system served multiple functions, controlling floods, providing irrigation, and creating a sacred ritual space. As with the Maya, we don’t know exactly what led to the decline of the Khmer, but environmental factors probably played a role. We know that monsoons weakened in the middle to late 14th century, and also that droughts would sometimes alternate with intensely wet monsoon years. It is likely that the increasingly complex hydraulic system at Angkor just couldn’t keep up with the fluctuations. This may not have directly led to the end of the line of Khmer kings, but it wouldn’t have helped them to maintain their power. Humans can’t survive without water, and just as it was a major concern for classical civilizations, water control remains an issue for the present and, especially the future. One billion people do not have access to safe drinking water and “by 2025 more than half the world’s nations will face shortages of fresh water...” So, if we believe that environmental shifts and failing water control systems led to the collapse of classical civilizations like the Maya and the Khmer, then we might be worried, given our current voracious thirst and poor record of water conservation. One lesson we might draw is that it’s a bad idea to build cities in places that don’t have water, Phoenix. But, a look back at the past might give us reason to be optimistic. After all, the Maya and the Khmer civilizations lasted hundreds of years, and were able to provide water using technology much less sophisticated than what we have at our disposal. And we have something else. As Steven Mithen, the author of the book on which most of this episode was based has written, “we do have knowledge about the ancient world to guide us in the present and future: understanding the past enables us to see the present more clearly.” Now like all fans of history, I'm a bit biased on that subject, but I tend to agree. And so we need to understand that history is not just about humans interacting with each other, but also about the ways that humans interact with the larger world. Thanks for watching. I'll see you next week. Crash Course is filmed here in the Chad and Stacey Emigholz Studio in Indianapolis and it's made possible by our Subbable subscribers, including our lead sponsor for today's video Mrs. Booth, who wants to thank Sunda, Burgoon, and the SCHS World History AP students or being awesome. And co-sponsored by Mike Burns from the Concordia School in Shanghai I want to say a special thank you to all of our Subbable subscribers, especially the educators. And as we say in my hometown, don't forget to be awesome.