Water.
The Epic Struggle for Wealth, Power, and Civilization.
by Steven Solomon.
PROLOGUE.
In 1763 a twenty-seven-year-old instrument maker named James Watt repaired a model of a Newcomen steam engine owned by the University of Glasgow. Britain was in the grip of a dire fuel famine resulting from the early deforestation of its countryside, and many of the primitive engines invented by Thomas Newcomen a half century earlier were working to pump floodwater from coal mines so that more coal could be excavated as a substitute fuel. While repairing the Newcomen machine, Watt had been startled by its inefficiency. Filled with the spirit of scientific inquiry then going on in the Scottish Enlightenment, he determined to try to improve its capacity to harness steam energy. Within two years he had a much-more-efficient design, and by 1776 was selling the world's first modern steam engine.
James Watt's improved steam engine was a turning point in history. It became the seminal invention of the Industrial Revolution. Within a matter of decades, it helped transform Britain into the world's dominant economy with a steam-and-iron navy that lorded over a colonial empire spanning a quarter of the globe. Britain's pioneering textile factories multiplied their productivity and output by shifting from waterwheel to steam power and relocating from rural riversides to new industrial towns. Steam-driven bellows heated coke furnaces to produce prodigious amounts of cast iron, the plastic of the early industrial age. Watt steam engines helped overcome Britain's fuel famine by pumping excess water out of coal shafts-and put the discharge to use by supplementing the water supply of the inland canals that had sprung up to expedite the growing shipments of coal from the collieries to the markets. Watt steam engines abetted the rise of urban metropolises, and improved the health and longevity of their residents, by pumping up freshwater from rivers for drinking, cooking, sanitation, and even firefighting. From Watt's steam engine, a new industrial society took hold that launched human civilization on an altogether new trajectory. World and domestic balances of power were recast, and mankind's material existence, population levels, and expectations increased more in just two centuries than they had in all the thousands of preceding years.
Yet as momentous as it was, Watt's innovation for exploiting steam power was but one of a long list of water breakthroughs that have been causally entwined with major turning points in history-much like the one unfolding before us today. Water has strongly influenced the rise and decline of great powers, foreign relations among states, the nature of prevailing political economic systems, and the essential conditions governing ordinary people's daily lives. The Industrial Revolution was akin to the Agricultural Revolution of about 5,000 years ago, when societies in ancient Egypt, Mesopotamia, the Indus Valley, and northern China separately began mastering the hydraulic arts of controlling water from large rivers for mass-scale irrigation, and in so doing unlocked the economic and political means for advanced civilization to begin. Ancient Rome rose as a powerful state when it gained dominance over the Mediterranean Sea, and developed its flourishing urban civilization at the heart of its empire on the flow of abundant, clean freshwater brought by its stupendous aqueducts. The takeoff event and vital artery of China's medieval golden age was the completion of its 1,100-mile-long Grand Canal, which created a transport highway uniting the resources of its wet, rice-growing, southerly Yangtze region with its fertile, semiarid Yellow River northlands. Islamic civilization's brilliance was sustained by the trading wealth that accompanied the opening of its once-impenetrable, waterless deserts by long-distance camel caravans that spanned from the Atlantic to the Indian oceans. Open oceanic sailing was the West's breakthrough route to world dominance, which it built upon through its leadership in steam, hydraulic turbines, hydroelectricity, and other water technologies of the industrial age. The sanitary and public health revolutions of the late nineteenth and early twentieth centuries that underpinned mankind's unprecedented demographic transformations sprung from efforts to provide freshwater free of filth and conditions inhospitable for disease-carrying organisms. America's historical rise, too, was explained in important part by its mastery and integration of its three diverse hydrological environments: exploitation of the industrial waterpower and transport potential of the year-round rivers in its temperate, rainy eastern half, highlighted by the catalytic Erie Canal; the naval domination of its two ocean frontiers, and ascendance to world leadership, following the epic building of the Panama Canal; and the triumph over its arid Far West by its pioneering innovation of giant, multipurpose dams inaugurated with its Depression-era Hoover Dam. The worldwide diffusion of giant dams, in turn, was a linchpin of the Green Revolution, and ultimately the emergence of today's global integrated economy.
That control and manipulation of water should be a pivotal axis of power and human achievement throughout history is hardly surprising. Water has always been man's most indispensable natural resource, and one endowed with special, seemingly magical powers of physical transformation derived from its unique molecular properties and extraordinary roles in Earth's geological and biological processes. Through the centuries, societies have struggled politically, militarily, and economically to control the world's water wealth: to erect cities around it, to transport goods upon it, to harness its latent energy in various forms, to utilize it as a vital input of agriculture and industry, and to extract political advantage from it. Today, there is hardly an accessible freshwater resource on the planet that is not being engineered, often monumentally, by man.
Whatever the era, preeminent societies have invariably exploited their water resources in ways that were more productive, and unleashed larger supplies, than slower-adapting ones. Although often overlooked, the advent of cheap, abundant freshwater was one of the great growth drivers of the industrial era: its usage grew more than twice as fast as world population, and its ninefold increase in the twentieth century rivaled the more celebrated thirteenfold growth in energy. By contrast, failure to maintain waterworks infrastructures or to overcome water obstacles and tap the hidden opportunities water always presents has been a telltale indicator of societal decline and stagnation.
Every era has been shaped by its response to the great water challenge of its time. And so it is unfolding-on an epic scale-today. An impending global crisis of freshwater scarcity is fast emerging as a defining fulcrum of world politics and human civilization. For the first time in history, modern society's unquenchable thirst, industrial technological capabilities, and sheer population growth from 6 to 9 billion is significantly outstripping the sustainable supply of fresh, clean water available from nature using current practices and technologies. Previously, man's impact on ecosystems had been localized and modest. Across heavily populated parts of the planet today, much of the rivers, lakes, and groundwater on which growing societies depend are becoming dangerously depleted by overuse and pollution. As a result, an explosive new political fault line is erupting across the global landscape of the twenty-first century between water Haves and water Have-Nots: internationally among regions and states, but just as significantly within nations among domestic interest groups that have long competed over available water resources. Simply, water is surpassing oil itself as the world's scarcest critical resource. Just as oil conflicts were central to twentieth-century history, the struggle over freshwater is set to shape a new turning point in the world order and the destiny of civilization.
Humanitarian crises, epidemic disease, destabilizing violence, and corrupt, failed states are already rife in the most water-deprived regions, where 20 percent of humanity lacks access to sufficient clean freshwater for drinking and cooking and 40 percent to adequate sanitation. Those who have predicted that the wars of the twenty-first century will be fought over water have foremost in mind the water-starved, combustible Middle East, where water looms omnipresently over every conflict and peace negotiation, and where those with oil are desperately trying to postpone their day of reckoning by burning it to pump dry aquifers and desalinate seawater in order to sustain farms and modern cities in the desert. Freshwater is an Achilles' heel of fast-growing giants China and India, which both face imminent tipping points from unsustainable water practices that will determine whether they lose their ability to feed themselves and cause their industrial expansions to prematurely sputter. The buffeting global impact will be especially far-reaching for the fates of water-distressed developing nations that are reliant on food imports to feed their swelling, restive populations. While the West, too, has some serious regional water shortages, its relatively modest population pressures and generally moist, temperate environments make it an overall water power possessing significant water resource advantages. If aggressively exploited, these advantages can help relaunch its economic dynamism and world leadership.
The lesson of history is that in the tumultuous adjustment that surely lies ahead, those societies that find the most innovative responses to the crisis are most likely to come out as winners, while the others will fall behind. Civilization will be shaped as well by water's inextricable, deep interdependencies with energy, food, and climate change. More broadly, the freshwater crisis is an early proxy of the twenty-first century's ultimate challenge of learning how to manage our crowded planet's resources in both an economically viable and an environmentally sustainable manner. By grasping the lessons of water's pivotal role on our destiny, we will be better prepared to cope with the crisis about to engulf us all.
PART I.
Water in Ancient History
CHAPTER ONE.
The Indispensable Resource.
Earth has aptly been called the "water planet." It is, like ourselves, 70 percent water. Alone among the solar system's apparently lifeless planets and moons, it contains abundant surface water in all three of its natural states-solid ice, gaseous vapor, and, most important, flowing liquid. Water's pervasiveness and indispensable capability to transform and transport other substances played a paramount role in forging Earth's identity as a planet and the history of all life upon it. Its deceptively simple molecular architecture of one oxygen and two hydrogen atoms possesses a mighty range of powers and functions unique among Earth's substances. Water is the planet's universal solvent: its extraordinary capacity to saturate, dissolve, and mingle with other molecules to catalyze essential chemical reactions makes it Earth's most potent agent of change. It is water that conveys the life force of nutrients and minerals upward against gravity to crops, treetops, and the blood vessels of human beings. It is water that enabled the earliest forms of life to evolve and help create the planet's oxygen-rich atmosphere. Water's anomalous property of becoming less dense and more expansive as it freezes helps fracture rocks to promote geological change and fortuitously means that an insulating layer of ice forms first over the top of lakes and rivers, protecting the water-living creatures below.
Movements of liquid water and ice sheets over eons likewise carved many of Earth's geographic landscapes and defined the changing characteristics of its habitats and climates. It is water's exceptional capacity to absorb great amounts of heat before heating up itself that moderates seasonal surface temperatures and prevents the planet from becoming a perennially steamy hothouse like Venus or a frigid desert like Mars. It is the absence of water in the soil that causes deserts to suffer the extremes of heat in daytime and intense cold at night, while it is water's presence that maintains comfortable ranges in temperate zones. Moving water creates and constantly redistributes the planet's skin-thin layer of fertile topsoil, which when cultivated and magically watered in the right amounts yields civilized man's daily bread-primarily wheat in the Mideast and Europe, rice in south Asia, maize and potatoes in the Americas, and tubers in Africa.
Among water's most indispensable qualities is that it is Earth's only self-renewing vital resource. Evaporated water precipitates in a desalinated and cleansed form over the planet through Earth's continuous water cycle to restore natural ecosystems and make sustained human civilization possible. Although the remarkably constant total volume of accessible, self-renewing freshwater is infinitesimally tiny as a virtual few droplets of the planet's total water, it has sufficed to provide all all of the water needed to support mankind throughout the entirety of human history-until today. of the water needed to support mankind throughout the entirety of human history-until today.
Water appeared on Earth early in the planet's infancy over 4 billion years ago, possibly through collisions with ice-bearing comets. Over time it assumed its familiar forms, such as oceans, ice sheets, lakes, rivers, streams, and wetlands on the surface, rainfall, snow, and water vapor in the air, and the invisible subsurface of shallow groundwater systems, soil moisture, and deep reservoirs of confined aquifers. Transmutations between water's three natural states help drive Earth's climate change cycles, prominently including the long fluctuations between cold, dry ice ages and warm, wet interludes like the present era.
Earth's last great ice age lasted some 90,000 years and reached its zenith about 18,000 years ago with ice covering one-third of the planet, compared to about one-tenth today. With so much water locked up in ice, global sea levels were about 390 feet lower. Now separate landmasses were traversable on foot. As the ice sheets melted and receded over the next several thousand years, they enriched the soil, filled underground aquifers, and created the contours of our present geography of lakes, rivers, and harbor-rich coastlines and filled in the shallow seas and channels-the English Channel, for instance, land-bridged England and continental Europe as recently as 9,000 years ago. Thick forests grew in the new temperate zones left behind by the glaciers, particularly in the Northern Hemisphere, where the glaciers had been concentrated. Then, about 10,000 years ago, the planet entered an anomalous interlude in which the climate became both warm and unusually stable. It was under these highly favorable climatic conditions that human civilization made its debut on Earth's stage.
Basic water conditions of aridity and moisture, seasonality and variable predictability patterns of precipitation, and river flow signatures and navigable lengths are defining elements of the planet's diverse range of habitats to which each occupying civilization tried to gainfully adapt during its few moments in history. Heat dispersal by ocean currents and the blanket of warm atmospheric water vapor help keep Earth habitable for humans from the equator to the subarctic latitudes. Within these boundaries are a half dozen main landscapes, each with a unique hydrological identity: Near the poles is the bitterly cold, low-rainfall, high-permafrost, and poorly drained tundra. The taiga, featuring large coniferous forests, lay south of the tundra in the Northern Hemisphere. Temperate forests, with good soil, ample rainfall, and rich flora, follow next, moving toward the equator. Then comes a belt of semiarid grasslands with less-fertile soil and erratic rainfall, such as in the barely cultivatable prairie of the North American Great Plains, Africa's savanna, and the steppes of central Asia. Interspersed among these regions are transition zones, notably one stretching from the Mediterranean to the Indus Valley and another in northern China, marked by drying, semiarid climates and several large rivers that flood over wide plains-the eventual cradle habitat of the ancient irrigation-farming-based civilizations. Between the 30-degree latitudes lie large deserts; around the equator are vast tropics with extreme rainfall, high temperatures, and rapid evaporation. Both are among the most water-fragile habitats on Earth-the former due to its dryness, and the latter due to its inundating, ever-soggy excess. Water also governs the crucial microclimates that exist within each basic zone. The seas play a dynamic role: it is the warm Atlantic Gulf Stream current that flows northeasterly from the Gulf of Mexico that keeps northern Europe wet and warm despite being at the same latitude as Canada's frigid Hudson Bay, just as the swift, northeasterly Kuroshio, or Japan Current, in the Pacific Ocean warms North America's coastal northwest. The Gulf Stream, in turn, also influences the prominent summer monsoons of Africa and Asia. Climatologists today postulate that the global conveyor belt circulation of deep and surface ocean currents acts as a key on-off switch of ice ages and is triggered by shifting mixtures of oceanic salinity and heat, particularly at the delicately balanced turnaround point in the North Atlantic. Similarly, the early signs of global warming are expected to express themselves in the form of more extreme precipitation events-more intense, frequent, and seasonally unpredictable storms, melts, and droughts. In short, every aspect of the past, present, and future of the planet and its inhabitants has been and will be powerfully influenced by water's pervasive impact.
Despite Earth's superabundance of total water, nature endowed to mankind a surprisingly minuscule amount of accessible fresh liquid water that is indispensable to planetary life and human civilization. Only 2.5 percent of Earth's water is fresh. But two-thirds of that is locked away from man's use in ice caps and glaciers. All but a few drops of the remaining one-third is also inaccessible, or prohibitively expensive to extract, because it lies in rocky, underground aquifers-in effect, isolated underground lakes-many a half mile or more deep inside Earth's bowels. Such aquifers hold up to an estimated 100 times more liquid freshwater than exists on the surface. In all, less than three-tenths of 1 percent of total freshwater is in liquid form on the surface. The remainder is in permafrost and soil moisture, in the body of plants and animals, and in the air as vapor.
One of the most striking facts about the world's freshwater is that the most widely accessed source by societies throughout history-rivers and streams-hold just six-thousandths of 1 percent of the total. Some societies have been built around the edges of lakes, which cumulatively hold some 40 times more than rivers. Yet lake water has been a far less useful direct resource to large civilizations because its accessible perimeters are so much smaller than riversides. Moreover, many are located in inhospitable frozen regions or mountain highlands, and three-fourths are concentrated in just three lake systems: Siberia's remote, deep Lake Baikal, North America's Great Lakes, and East Africa's mountainous rift lakes, chiefly Tanganyika and Nyasa. Throughout history, societies have also widely accessed shallow, slowly flowing groundwater, which is the underground counterpart of surface rivers and lakes.
The minuscule, less than 1 percent total stock of accessible freshwater, however, is not the actual amount available to mankind since rivers, lakes, and shallow groundwater are constantly being replenished through Earth's desalinating water cycle of evaporation and precipitation-at any given moment in time, four-hundredths of 1 percent of Earth's water is in the process of being recycled through the atmosphere. Most of the evaporated water comes from the oceans and falls back into them as rain or snow. But a small, net positive amount of desalted, cleansed ocean water precipitates over land to renew its freshwater ecosystems before running off to the sea. Of that amount, civilizations since the dawn of history have had practical access only to a fraction, since two-thirds was rapidly lost in floods, evaporation, and directly in soil absorption, while a lot of the rest ran off in regions like the tropics or frozen lands too remote from large populations to be captured and utilized. Indeed, the dispersion of available freshwater on Earth is strikingly uneven. Globally, one-third of all streamflow occurs in Brazil, Russia, Canada, and the United States, with a combined one-tenth of the world's population. Semiarid lands with one-third of world population, by contrast, get just 8 percent of renewable supply. Due to the extreme difficulty of managing such a heavy liquid-weighing 8.34 pounds per gallon, or over 20 percent more than oil-societies' fates throughout history have rested heavily on their capacity to increase supply and command over their local water resources.
Some societies developed in landscapes that offered relatively abundant, easily accessible, water resources with reliable availability and moderate variations; others have been hindered by more water-fragile and arduous habitats marked by dearth or excess and, worst of all, frequent, unpredictable shocks like extreme droughts and floods that overwhelmed otherwise sound hydraulic planning. Each unique environment imposed opportunities and constraints that helped shape that society's organizational patterns and history.
Adaptation is a constant necessity because water conditions are in flux. As historians Ariel and Will Durant have written, "Every day the sea encroaches somewhere upon the land, or the land upon the sea; cities disappear under the water...rivers swell and flood, or dry up, or change their course; valleys become deserts, and isthmuses become straits...Let rain become too rare and civilization disappears under sand... let it fall too furiously, and civilization will be choked with jungle." Natural secular climate change alters conditions slowly, but dramatically, over time. As recently as 5,000 years ago the Sahara Desert was verdant grassland with hippopotamuses, elephants, and cattle herders, whose water has since evaporated and seeped away into deep, fossil aquifers, while today's desiccating, windblown northern plain of the Yellow River was a watery swampland at the time it was a cradle of ancient Chinese civilization. Almost everywhere civilization has taken root, man-made deforestation, water diversion, and irrigation schemes have produced greater desiccation, soil erosion, and the ruination of Earth's natural fertility to sustain plant life.
How societies respond to the challenges presented by the changing hydraulic conditions of its environment using the technological and organizational tools of its times is, quite simply, one of the central motive forces of history. Repeatedly, leading civilizations have been those that transcended their natural water obstacles to unlock and leverage the often hidden benefits of the planet's most indispensable resource.
CHAPTER TWO.
Water and the Start of Civilization In A Study of History, A Study of History, British historian Arnold Toynbee influentially posited that the history of civilizations was centrally driven by a dynamic process of responses to environmental challenges. Difficult challenges provoked exceptional, civilizing responses in ascendant societies, while inadequate responses contributed to stagnancy, subordination, and collapse in declining ones. Prominent among the environmental challenges was water. British historian Arnold Toynbee influentially posited that the history of civilizations was centrally driven by a dynamic process of responses to environmental challenges. Difficult challenges provoked exceptional, civilizing responses in ascendant societies, while inadequate responses contributed to stagnancy, subordination, and collapse in declining ones. Prominent among the environmental challenges was water.
Throughout history, wherever water resources have been increased and made most manageable, navigable, and potable, societies have generally been robust and long enduring. Those that succeeded in significantly increasing their command and supply regularly were among the few that broke out of history's normative condition of changelessness and bare subsistence to enjoy spurts of prosperity, political vigor, and even momentary preeminence. Often major water innovations leveraged the economic, population, and territorial expansions that animated world history. Those unable to overcome the challenge of being farthest removed from access to the best water resources, by contrast, were invariably among history's poor.
Water's leading role in civilization was visible in the landscape of natural and man-improved waterways that ever have been history's directional arrows of exploration, trade, colonial settlement, military conquests, agricultural expansion, and industrial development. Wherever navigable waterways converged or where key river crossings or favorable harbors were established, influential urban centers arose at the center of civilizations. In every age, whoever gained control of the world's main sea-lanes or the watersheds of great rivers commanded the gateways of imperial power. If the advance of civilization could be charted on an electronic, time-sequenced map of the globe, it would show early city-states unifying up river valleys, along seacoasts, then spreading across nearby seas, and finally extending westward to link all the world's oceans and waterways in an ever-denser and faster-traveled web that has evolved into today's fitfully integrated global economy and world civilization.
It was also a common pattern of history that expansions driven by intensified use of water and other vital resources were followed by population increases that in turn so increased consumption that they ultimately depleted the further intensification capacity of the society's existing resource base and technologies. Such resource depletions thus presented each society with a moving target of new challenges requiring perpetually new innovative responses to sustain growth. This population-resource equation-the ever-shifting balance between each society's population size and the resources and know-how within its means to produce enough goods to sustain it-and its activating cycle of intensification and resource depletion, too, was one of the central dynamics of human and water history. History was littered with societies that declined simply because they could not overcome the deleterious local-resource depletions and population expansions accompanying their own initial success.
Signature water challenges evolved from era to era. Breakthrough responses that harnessed new water resources by novel means in one epoch sowed new conditions from which emerged the defining water challenges, and opportunities, of the next. At each turn of the cycle, the equation of water advantages recalibrated, altering the power balances among states and interest groups. Successful responses in every epoch, however, were invariably marked by intensified productivity in at least one of the five principal, interrelated ways water has been used throughout world history: (1) domestically for drinking, cooking, and sanitation; (2) economic production for agriculture, industry, and mining; (3) power generation, such as through waterwheels, steam, hydroelectricity, and as coolant in thermal power plants; (4) for transportation and strategic advantage, militarily, commercially, and administratively; and (5) of growing prominence today, environmentally to sustain vital ecosystems against natural and man-made depletions and degradations. Whenever a major breakthrough occurred in any of these principal uses, such as Watt's improvement of the steam engine, it often had an outsized, transformational impact upon history by converting what had been a water impediment into a dynamic force for expansion. Time and again, too, an ascendant civilization's expansion involved the fusion of two or three diverse hydrological environments with its original habitats, such as the combining of a river's swampy delta with its upper river valley, a semiarid farming region of millet and wheat with another dominated by verdant monsoonal hillsides and rice farming, or a zone of wide deserts or temperate, rain-fed river and farming lowlands with the opportunities of open seas. Dynastic declines and the fall of expansive civilizations, when they came, also often occurred along the same hydrological fault lines.
Water tied man to Earth with a special bond. Fetuses gestated in water. Man and environment mutually exchanged water through the natural biological cycles of perspiration, exhalation and evacuation, and replenishment by drinking. A healthy, active person needed to consume at least two to three quarts of freshwater daily to stay alive-there was no substitute. Thirst came with only a 1 percent water deficiency; a 5 percent shortfall produced a fever; a 10 percent dearth caused immobility; death struck after about a week with a 12 to 15 percent water loss.
The special affinity between water and man was reflected in water's primary role in creation stories in diverse cultures throughout the world. "Almost every mythology sees the origins of life coming out of water," observed mythologist Joseph Campbell. "And, curiously, that's true. It's amusing that the origin of life out of water is in myths and then again, finally, in science, we find the same thing." Water was one of the Greeks' four primary terrestrial elements and one of five in ancient China and Mesopotamia. Water still plays a central role in common religious rituals of purification from Hinduism and Shinto to Islam, Christianity, and Judaism. Whether it was the rain dance of a tribal shaman, the ritual opening of an irrigation canal by an ancient king, or the dedication of a giant hydroelectric dam by a twentieth-century president, provision and control of sufficient water has conferred political legitimacy in all forms of human society.
Yet water's unique natural characteristics always simultaneously presented a double-edged challenge to civilized man: it was at once the necessary resource of survival that when brought under control yielded immeasurable benefits to society, but it also imposed one of the most formidable natural obstacles and limitations to growth. Water sustained life, but also, through the devastating shocks of drought, flood, and mudslide, could obliterate it on a terrifying scale, as witnessed in the quarter of a million deaths in the Indian Ocean tsunami of late 2004 and the traumatic 2005 inundation of New Orleans. While man needed water to live, drinking contaminated water and exposure to stagnant water infested with disease-carrying organisms was by far the leading cause of debilitating illness, infant mortality, and short life spans for all of history. Rivers, seas, and the waterless oceans of the deserts could be protective or constraining, in turn a separating defensive buffer between societies, or a bridge between peoples to open communication and trade, or a highway of invasion and conquest. Irrigation watered cropland, but also raised fertility-killing salts to the soil's surface. The secret of water's extraordinary potency to transform history was that whenever a society, in its constant struggle to wrench a surplus from nature, was able to innovate to make its water resources more manageable, abundant, potable, or navigable, it not only merely liberated itself from a major water-bound obstacle and constraint, but also unlocked and harnessed more of water's inherent, often hidden catalytic potential for growth.
A radical transformation in man's relationship to water played a pivotal role in the great transition to settled agriculture at the start of history. After eons as hunter-gatherers following their alimentary mainstay of herds of giant herbivores such as steppe bison, giant elk, and woolly mammoth from seasonal water hole to water hole, and gathering wild, edible plants along the way, some human tribes about 10,000 years ago began to adopt a settled economic life predicated upon the artificial transformation of nature through farming. As a hunter-gatherer, primitive man used water as he found it. As a settled farmer, managing water resources became essential to survival and growth. radical transformation in man's relationship to water played a pivotal role in the great transition to settled agriculture at the start of history. After eons as hunter-gatherers following their alimentary mainstay of herds of giant herbivores such as steppe bison, giant elk, and woolly mammoth from seasonal water hole to water hole, and gathering wild, edible plants along the way, some human tribes about 10,000 years ago began to adopt a settled economic life predicated upon the artificial transformation of nature through farming. As a hunter-gatherer, primitive man used water as he found it. As a settled farmer, managing water resources became essential to survival and growth.
Environmental change in climate and water conditions offered the most likely explanation of the mystery why hunter-gatherers suddenly traded their relatively undemanding and healthy lifestyle for the more-labor-intensive, less-healthy challenges of farming life. As the ice age glaciers retreated northward due to increased global warming and moisture at the start of the present warm period, tundra mosses and grasses also retreated and were gradually replaced by thick temperate forests. This forced the large herds ever northward after their food supply. An abrupt, 1,300-year-long mini ice age around 12,900 years ago may have accelerated the herds' disappearance. Some groups gave up following the herds to hunt smaller animals, fish, and gather the wild cereals and other edible plants that flourished on open landscapes. Experiments with settled farming and animal domestication ensued. Gradually, domesticated seed agriculture based on wild barley and emmer wheat grasses emerged in the Middle East's Fertile Crescent, which had transformed from prairie to semiarid landscapes as the climate changed. Farmers began to work the amply rain-fed, well-drained, and easier-to-work soils of wooded river valley hillsides with simple stone and wooden axes, hoes, and sickles. Slashing the bark killed enough trees for sunlight to nourish seeds planted in the loose leaf mold around the trunks. Scattered ash from burning the dead trees after two or three plantings temporarily revitalized the soil's depleted fertility for another few seasons. Finally, weed invasion forced such "slash-and-burn" method farmers to abandon the land and move on to clear new plots. Early walled, irrigated farming and trading settlements ultimately arose in a few favored locations. Jericho, possibly the world's oldest true city from about 7000 BC, with about 3,000 inhabitants, internal cisterns, grain storerooms, and a tower within its 10 acres, was situated at the lower slope of Mount Carmel near an ample "sweet," or freshwater, spring-in contrast to "bitter" water with traces of salt-known in the Bible as Elisha's Spring that irrigated the small, fertile, once-forested Jordan River valley and was later to lure the biblical Joshua and his Hebrew followers after the exodus from Egypt. Jericho's location also gave it access to the precious salt and trade routes of the Dead Sea. Salt had become vital to maintaining body fluid once the human diet had shifted to cereals.
Slash-and-burn farming on hillsides had one major drawback. It was always extremely vulnerable to erratic rainfall. The response to this environmental challenge produced one of history's most momentous innovations-the rise of large-scale, irrigated agriculture, and with it the birth of civilization. The earliest irrigated farming civilizations all developed along the semiarid plains of large, flooding, soil-bearing rivers where precipitation was too scant for rain-fed agriculture. In Mesopotamia, where civilization arose first, some hillside farmers moved down into the stoneless, muddy floodplains and swamps of the lower Tigris-Euphrates river valley in Sumeria near the mouth of the Persian Gulf. It would seem to be counterintuitive for farmers to relocate into a forbidding, miasmic habitat marked by scant rainfall and infestations of deadly waterborne diseases, and prone to violent floods and droughts. Yet the rivers possessed two prized resources that trumped all drawbacks-an ample, reliable, year-round supply of freshwater and a self-renewing source of fertile silt that spread across the cropland with the floods. If productively managed by the arduous building and maintenance of irrigation waterworks, the water supply and silt could produce bountiful yields many times greater than were possible on the rain-dependent hillsides. By specializing in the mass production on cultivated fields of one or two staples like wheat, barley, or millet, farm communities that mastered the techniques of irrigation ultimately produced grain surpluses that were stored as reserves for bad seasons when the floods were excessive or inadequate. These food surpluses in turn yielded rising populations, big cities, and all the early expressions of civilization-arts, writing, taxation, and the first large states-that were the precursors of modern society. The development of reed and wooden rafts, powered by oar and sail, also turned the rivers into high roads for trade, communication, and political integration. As political power concentrated and production of field seed grains expanded with better organization, these early, river-based irrigation civilizations became cradles of history's first great empires.
Irrigation farming societies also developed in other hydrological habitats based upon staple crops other than field agriculture of wheat and related grains. By the third millennium BC transplanted rice was being extensively cultivated in paddies along the naturally flooded fields of the monsoonal river valleys of Southeast Asia. This garden cultivation, too, required sophisticated, labor-intensive water management-storing the downpour, transplanting rice plants, and submerging and draining paddies at just the right levels and seasons, for instance, to support much more densely populated, civilized communities. Yet the monsoon-fed wet rice garden cultivation was not done on a scale as grand or politically centralized as in the semiarid wheat field agriculture, river-irrigation states. The seasonal rains delivered sufficient natural water supplies to support independent, smaller communities that did not need, and indeed could better resist, any centralized government command. In fact, the case of early wet rice societies supported the general observation that the way water resources presented themselves exerted a strong influence on the nature of the society's political system. By and large, where wealth-creating water resources were widely and easily accessible and not dominated by the existence of an arterial transport and irrigating waterway, there was a stronger tendency for smaller, more-decentralized, and less-authoritarian regimes to prevail.
The spread of civilization to cropland watered only by rainfall about a thousand years after the rise of large-scale irrigation societies represented one of history's most enduring, if slow-moving, expansive forces. In wheat-growing regions, the key development was the diffusion of the animal-powered wooden traction plow that facilitated the cultivation of large enough tracks to sustain fixed village communities. Yet nowhere did rain-fed farming ever produce the food surpluses, population densities, grand civilizations, and empires supported by irrigation; their heyday on the world stage, rather, depended upon the advent of other, later technological developments. Thus, for nearly all of history when wealth came from agriculture, one of the central dividing lines of human civilization lay between water-rich, irrigated agrarian states and water-challenged, sparsely populated, relatively poor, small, rain-fed farming communities.
Two other historical dividing lines were also marked by water usage. One was the gradual emergence of seafaring civilizations on the fringes of antiquity's irrigation empires in lands with marginal domestic agricultural fertility that earned their wealth principally by trading among neighboring states. Sea trade, which exploited the fast and cheap navigation potential of water's buoyancy, advanced in the Mediterranean Sea with the development of sail and oar-powered wooden cargo ships suitable for its relatively calm, enclosed waters and evolved very gradually into a significant historical force by the second millennium BC. In the Mediterranean, the Red Sea, and the Indian Ocean, sea traders facilitated cross-cultural and commercial exchange based upon market-set prices that over many centuries helped propagate a small but vibrant unregulated economic sphere in which the early beginnings of the modern market economy were nurtured.
The other great water demarcation line was the barbarian divide-the existential clash of societal organization and lifestyles between the nomadic pastoralist descendants of primitive hunter-gatherers and the expanding, civilized agricultural realm. The militarily skillful barbarian tribes of the central Asian steppes, the desert Bedouins of the Arabian Peninsula, and later the Nordic Vikings in their river longboats were far fewer in number and ranged Earth's more water-fragile and less-yielding landscapes, herding their animals between water holes, and trading with or, when strong enough, raiding or demanding tribute from civilized settlements. Periodically, they gathered enough strength under great warrior leaders to lead fearsome invasions that disrupted, overwhelmed, and ultimately reinvigorated civilized empires across the world. History recorded four great barbarian waves, starting with the Bronze Age charioteers of 17001400 BC and ending with the Turkish-Mongol invasions from the 700s through the fourteenth century, when the age of gunpowder and sheer manpower advantages decided matters for settled civilization. The slow, fitful expansion of civilized society around the globe was always synchronized with the breakthroughs and setbacks in irrigated and rain-fed cultivation, some of which were landmark events of world history. Wherever farming took hold, population advanced. In 8000 BC the planet was populated by about 4 million hunter-gatherers. After 5000 BC it began to double every 1,000 years. By 1000 BC world population had reached about 50 million. Then, under the prosperous shield of order-providing empires, it generally accelerated. By the late second century AD, some 200 million people inhabited the world. Even Watt's steam engine and the Industrial Revolution did not lessen civilization's reliance on agriculture. Instead, they provided new tools to enhance innovation production to feed the growing demand of a world inhabited by 6.5 billion by the early twenty-first century. Despite the dramatic expansion of total cropland, water volumes, and agricultural technologies, one thing that has not changed since ancient times is man's greater reliance on irrigation to feed himself. Today, two-fifths of the world's food is being grown on less than one-fifth of the planet's irrigated, arable land. All of human society today shares an irrigation legacy with the cradle civilizations of antiquity.
CHAPTER THREE.
Rivers, Irrigation, and the Earliest Empires One of the striking common features of ancient history was that all of mankind's four great cradle civilizations were wheat, barley, or millet field irrigation agricultural societies that arose in semiarid environments alongside large, flooding, and navigable rivers. For all their differences, Egypt around the Nile, Mesopotamia along the twin Tigris and Euphrates, the Indus civilization around the Indus, and China along the middle reaches of the Yellow River also shared similar political economic characteristics. They were hierarchical, centralized, authoritarian states ruled by hereditary despots claiming godly kinship or mandate in alliance with an elite class of priests and bureaucrats. All power was imposed top-down through control of water, which was the paramount factor of economic production, and managed through the marshaling of mass labor.
In his classic 1957 work, Oriental Despotism, Oriental Despotism, Karl A. Wittfogel proposed a causal linkage between centralized authoritarian states and specialized, mass irrigation agriculture. The overriding challenge of so-called hydraulic society, he posited, was how to intensify exploitation of its silt-spreading, flooding river's potential water resources. The larger the river, the greater was the potential productive wealth, population density, and power of the ruling hydraulic state. Yet only centralized planning and authoritarian organization on an immense scale could exploit water resources to their productive maximum. Surplus yields depended critically upon delivery of adequate supplies of water at the right time to the right places as well as protection against catastrophic flooding. This required the forced, often brutal mobilization of hundreds of thousands, and sometimes millions, of peasant laborers during lulls in the farming season to construct and maintain irrigation and diversionary canals, sluices, water storage dams, protective dikes and levees, and other waterworks. Karl A. Wittfogel proposed a causal linkage between centralized authoritarian states and specialized, mass irrigation agriculture. The overriding challenge of so-called hydraulic society, he posited, was how to intensify exploitation of its silt-spreading, flooding river's potential water resources. The larger the river, the greater was the potential productive wealth, population density, and power of the ruling hydraulic state. Yet only centralized planning and authoritarian organization on an immense scale could exploit water resources to their productive maximum. Surplus yields depended critically upon delivery of adequate supplies of water at the right time to the right places as well as protection against catastrophic flooding. This required the forced, often brutal mobilization of hundreds of thousands, and sometimes millions, of peasant laborers during lulls in the farming season to construct and maintain irrigation and diversionary canals, sluices, water storage dams, protective dikes and levees, and other waterworks.
The bulky, inherently hard-to-manage physical property of liquid water itself, noted Wittfogel, "creates a technical task which is solved either by mass labor or not at all." Once conscripted and organized for waterworks, the workforces were readily mobilized by the state to construct its other celebrated grand monuments of hydraulic civilizations-pyramids, temples, palaces, elaborate walled cities, and other defensive fortifications like China's Great Wall. In further support of his hydraulic theory, Wittfogel observed that similarly organized theocratic, authoritarian, gigantic public-works-building agrarian societies, based on miraculously easy and fast-growing maize and potatoes, and responding to other labor-intensive water management challenges, were reinvented again much later in the New World, among the Olmec-Maya on cultivated swamp mounds of the tropical lowland habitats of Central America and on the bleak, terraced, and irrigation-channeled mountain plateaus of the Andes inhabited by the Incas and their predecessors.
Wittfogel's theory of hydraulic society fueled much debate over the decades, including whether the cooperative needs of irrigation created the large centralized state or vice versa. Yet such debate often sailed past the most salient point: the two social formations were complementary; they reinforced one another. Power and social organization in such societies depended absolutely upon regimented, concentrated control of the water supply. Whenever the water flow was interrupted, whether from natural or political causes, crop production fell, surpluses dissipated, dynasties and empires toppled, and starvation and anarchy threatened the entire social order. Ancient hydraulic societies tended to thrive where two prominent conditions existed: first and foremost, where the best available resources of water were highly concentrated in the state-controlled irrigation source; second, where the unifying presence of a dominating, navigable river gave the state command over regional communication, commerce, political administration, and military deployment.
For millennia authoritarian irrigation societies produced the most advanced civilizations in the world. Although the hydraulic model would be supplemented, and eventually superseded, by new social formations, it produced a recognizable prototype that has endured through history. Whatever the era, huge water projects requiring vast mobilization of resources tended to go hand in hand with large, centralized state activity. Vestiges of this hydraulic tendency were evident in the giant dams built in the twentieth century by centralizing liberal democratic, communist, and totalitarian states, often in the early stages of restoration periods.
Ancient Egypt was the prototype hydraulic civilization because its river, the Nile, was the consummate hydraulic waterway. The Greek historian Herodotus, who visited in 460 BC, famously described Egypt as the "Gift of the Nile." Indeed, Egypt's history was-and still is-almost entirely determined by what happened on and around the natural phenomena of its great river.
The Nile provided everything that was needed in virtually rainless Egypt. It was the only large source of irrigation water and its annual flood brought a thick, self-renewing layer of fertile black silt for its farmland. Unlike other great rivers, the annual flood season arrived and receded with clockwork predictability and in miraculous synchronization with the agricultural cycle of planting and harvesting. It was one of the easiest landscapes to manage for irrigation. Egyptian farmers needed merely to construct embankment breeches, sluice gates, extension channels, and some simple dikes to retain sufficient floodwater to soak the soil in the cultivated, low-lying basins beyond the river before releasing the excess to the next basin downstream. The Nile's steep gradient, furthermore, kept the river flowing steadily with good drainage that helped to flush out the soil-poisoning salts that afflicted artificial irrigation systems everywhere else. Indeed, the Nile was world history's only self-sustaining, major river irrigation system.
The Nile's natural beneficence also bestowed Egypt with a second great gift-it was a rare two-way two-way navigable river. Its current and surface wind moved in opposite directions all year round, so it was possible to float downriver with the current and sail south upriver in simple, broad-bottomed vessels with square sails. navigable river. Its current and surface wind moved in opposite directions all year round, so it was possible to float downriver with the current and sail south upriver in simple, broad-bottomed vessels with square sails.
Finally, the wide, waterless desert beyond both banks provided a defensive barrier that helped insulate ancient Egyptian civilization against large-scale invasion for centuries. As a result of Egypt's total reliance on its single grand river, the flow of political power to the center in Egypt was simple, total, and unchanging. Throughout history, whoever controlled the Nile also controlled Egypt.
The Nile's bounty, however, depended upon one unpredictable variable beyond the Pharaoh's control-the extent of the river's annual flood. Excessive flooding inundated entire villages and wiped away cropland. Far worse were years of low flooding when insufficient water and silt resulted in famine, desperation, and chaos. To an astonishing degree, dynastic rises and declines throughout Egypt's long history correlated to cyclic variations in the Nile's floods. Good flood periods produced food surpluses, political unity between Upper Egypt's Nile Valley and Lower Egypt's marshy delta, waterworks expansions, Egyptian civilization's glorious temples and monuments, and dynastic restorations. Extended years of low flood, by contrast, were dark ages of privation, disunity, and dynastic collapses. Without Nile water, neither the wise nor the corrupt could rule effectively. Pharaoh's kingdom fractured between valley and delta and sometimes further into competing precincts ruled by warlords and menaced by bandits.
Ancient Egypt was marked by the rise of three great kingdoms-the Old Kingdom (circa 31502200 BC), the Middle Kingdom (20401674 BC) and the New Kingdom (15521069 BC)-and their respective dissolutions into the intervening First, Second, and Third Intermediate Periods. Nile flood levels were so important to determining tax revenue from the harvest and overall governance that they were assiduously monitored by priestly technocrats from Egypt's early beginnings by nilometers, which were depth gauges marked off on stones and originally situated at temples along the river. Nilometer records show that the fates of Egypt's subsequent occupiers were likewise driven by cyclic oscillations in the flood level of the Nile. In short, the rhythms of the Nile framed all the essential parameters of history and life in Egypt, including food production, population size, extent of dynastic reach, and conditions of peace or strife.
Nile flood levels, in turn, ultimately depended upon an occurrence far beyond Egypt's borders-the degree of the summer monsoonal rains that fell at the headwaters of the Blue Nile. The Blue Nile started in Ethiopia's Abyssinian plateau at over 6,000 feet at a spring venerated by the modern Ethiopian Orthodox Church. The southernmost source of the White Nile, the river's other main branch, was at a spring in Burundi in Africa's equatorial plateau lake region. The Blue and White Niles came together just north of Khartoum in the Nubian Desert before entering Egypt. By the time the Nile emptied into the Mediterranean Sea, its 4,168-mile journey made it the world's longest river. Yet by total water volume it was comparatively small-only 2 percent of the mighty Amazon, 12 percent of the Congo, 15 percent of the Yangtze, 30 percent of the Mississippi and 70 percent of Europe's Danube, Pakistan's Indus, or America's Columbia rivers. Virtually none of its net flow originated within rainless Egypt's own hot, arid borders. Since about half the White Nile's water evaporated in Sudan before reaching Egypt, some four-fifths of the river flow sustaining Egyptian civilization, and nearly all its precious silt, originated in the highlands and deep ravines of Ethiopia.
Every summer monsoonal rains swelled the Nile's tributaries in Ethiopia, triggering the downstream rush and the annual flood. The river normally rose in northern Sudan by May and by June reached the first cataract near Aswan in southern Egypt. By September the entire Egyptian Nile Valley floodplain was inundated under a turbid, reddish-brown lake, which then began to recede into the main river channel but left behind its thick, odorous residue of fertile black silt. By managing the overflow of water with simple irrigation works, Egyptian farmers produced the ancient Mediterranean's richest breadbasket. Crops were planted in the waterlogged soil following the inundation and harvested in late April and May after the floods were gone; during the early summer the mud baked and cracked under the hot sun, aerating and reinvigorating the soil. Seeds were cast over the ground and buried by wooden scratch plows-a simple hoelike, wheelless implement dragged by a draft animal. Thousands of years of annual flood deposit built up 10-foot-high natural embankments ideal for human settlements on both sides of the river's nearly 600-mile length through the narrow Nile Valley. Just over the embankments were low-lying basins for farming, a total area less than modern Switzerland, into which farmers channeled the Nile's resources of water and silt to produce Egypt's emmer wheat and barley.
Ancient Egypt & Nile [image]
The Nile in Egypt consisted of two distinct hydrological and political zones. Upper Egypt was the Nile Valley from the first cataract at Aswan. Just north of modern Cairo began the fan-shaped, rich, labyrinthine 100-mile-long delta of reedy marshes and lagoons of Lower Egypt, whose topography and history were also partly molded by the fluctuating sea levels of the Mediterranean. When the kingdom was robust, one Pharaoh wore the double red and white crown symbolizing the unity of delta and valley, respectively.
The first to wear the double crown was Egypt's traditional founder Menes, the so-called King Scorpion, who as prince of Upper Egypt finally conquered the delta around 3150 BC and established Egypt's capital at Memphis at the delta's head. Power had consolidated over the previous centuries in both the delta and the valley from the battles of dozens of independent chieftains, themselves descendants of the nomadic hunter-gatherer bands who had settled closer to the river's water supply during the gradual drying of the regional climate. Whether Menes was a ceremonial title or an actual historical king, possibly identified with the early ruler Narmer, his legend accurately reflected the essential origins of Egyptian civilization, including his close personal identification with irrigation waterworks, and the fundamental duty of the ideal Pharaoh to control the flow of the Nile. Menes' royal ceremonial macehead, for instance, shows him as a conqueror wearing the white crown of the valley, dressed in a kilt and belted loincloth with a bull's tail, and using a hoe to dig an irrigation canal, while another figure removes the excavated dirt in a basket.
Menes' macehead paralleled records from other hydraulic societies showing sovereigns immersed in the daily functions of opening and closing floodgates, allocating irrigation water to peasants' fields, and directing waterworks construction. The older hydraulic civilization in Sumeria, with which Egypt had sea contact from the earliest times, was notably influential in the developmental trajectory of ancient Egypt's methods and tools. The hydraulic nature of ancient Egypt was also evidenced in the world's first recorded dam, a 49-foot masonry giant, supposedly built around 2900 BC to protect Menes' capital at Memphis from floods. Actual archaeological remains exist of another similar, masonry-faced, earthen reservoir dam 37 feet tall and 265 feet wide at the base, from between 2950 and 2700 BC about 20 miles south of modern Cairo. Far more common in ancient Egypt were simple, often short-lived earth-and-wood diversion dams to direct irrigation water during flood season.
The Nile's propitious characteristics and the simple, irrigated basin agriculture it supported visibly shaped all aspects of Egyptian culture, society, and daily life. At the apex of the hierarchical Egyptian state was the Pharaoh, the absolute sovereign who in the Old Kingdom was viewed as a living god who owned all the land and controlled the river. Supporting him was an administration of elite priest-managers, with such indicative titles as "inspector of the dikes," "chief of the canal workers," and "watcher of the nilometers." The priests' divine authority was validated by their command of such vital esoteric secrets as when the river would flood or recede, and when was the right moment to plant and to sow, and the technical engineering of durable waterworks. The state's totalitarian power was underpinned by the centralized collection, storage, and distribution of grain surpluses produced in good years. Labor on waterworks, and other state projects, was carried out by one of the oldest forms of manpower mobilization in world history-the compulsory, seasonal corvee. The peasant's duty to Pharaoh and state was so absolute that it continued into the afterlife; the peasant was often buried with clay statuettes that symbolically stood in for his perpetual work obligations after death. Control of water also helped foster the development of many of Egypt's early sciences and arts. The learned elites created calendars to facilitate farming, surveying tools to regrade and mark off land after inundations, and maintained written administrative records on parchment manufactured from the common papyrus reeds of the Nile delta. Papyrus, the oldest form of paper, represented one of history's earliest uses of water in manufacturing. It was fabricated by peeling away the outer covering of the reed, then cutting the stalks into thin strips, which were then mixed with water to activate its innate bonding properties. The thin strips were then layered, pressed, and dried.
A second linchpin of Pharaoh's power, repeated in societies throughout every age of history, was control of the region's key water transport highway. Control of shipping on the Nile allowed the Pharaoh to regulate all important transport of people and goods, and thus provided the means to exert effective rule over all Egypt. Barges laden with grain, oil jars, and other goods commonly plied Nile ports from Memphis to Thebes to Elephantine Island and, after 2150 BC, beyond to Nubia in modern Sudan when a canal was excavated through the solid granite at the Aswan water falls. The Nile artery, the richness of its valley and the delta, the predictable onset of its floods, and its protective surrounding desert also rendered Egypt one of world history's most inward-looking, changeless, rigidly ordered, and longest-enduring civilizations. Yet Egypt's simple basin agriculture was only a one-crop system with limited capacity to increase output beyond a certain ceiling. This capped Egypt's maximum population level and left Egyptians highly susceptible to famine and instability during prolonged periods of low Nile floods.
From about 2270 BC onward, the central authority and cultural grandeur of the Old Kingdom gradually disintegrated amid anarchic warfare among provincial chieftains, banditry, and famine. A climatic dry period in the Mediterranean region, which simultaneously disrupted civilization in Mesopotamia, contributed to a series of low floods on the Nile that undermined the agricultural economic basis of society.
Egyptian civilization's first dark age of disunity and competing fiefdoms lasted nearly two centuries. The return of abundant Nile floods resuscitated agricultural prosperity and facilitated the reunification into the Middle Kingdom following the military conquests and diplomacy of the rulers of Thebes in Upper Egypt in about 2040. The Middle Kingdom restoration was also associated with large new water projects and intensified food production, including the expansion of cropland into a large, swampy depression fed by high Nile floods called Faiyum. It was the prosperity of the Middle Kingdom that may have drawn the biblical family of Jacob to Egypt's delta during a period of drought and political upheaval in Palestine.
A series of droughts weakened the central state's power to resist Egypt's first full-fledged foreign invasion. In 1647 BC, the Hyksos, a Semitic-Asiatic group of Bronze Age charioteers who had penetrated Egypt through the increasingly porous Sinai Desert frontier, seized control of the delta almost without resistance. The Hyksos conquest traumatically altered Egyptian history by forcibly ending the cultural sense of fixed order and security that its isolated, predictable river environment had provided for so long.
When the hated Hyksos were finally expelled a century later and Egypt reunified under its New Kingdom, which would last half a millennium, Egypt assertively projected its cultural renewal outward through extensive foreign sea trade, military conquests of the Levant to the Euphrates and of Nubia in the south, and monuments of its native culture, such as the outsized temples at Luxor and Karnak, the modern Thebes. The New Kingdom renaissance coincided with three centuries of good Nile floods.
Harvests were increased by the intensive use of an ancient water lifting device, the shadoof. The shadoof, which likely originated in Mesopotamia centuries earlier and reached Egypt gradually, could raise 600 gallons of water per day. The device itself was a long pole on a fulcrum counterbalanced by a bucket at one end and a stone weight at the other. Two men operated it. One filled the bucket while the other leaned on the stone to lift the bucket and pour its contents into an irrigation channel that carried it to small plots. The shadoof allowed Egyptian farmers to irrigate a supplemental crop outside the main flood season.
In subsequent centuries, more powerful water-lifting devices were applied to the Nile. Archimedes' screw, invented by Greek polymath Archimedes and introduced by Hellenic rulers in the century following Alexander the Great's conquest in 332 BC, was a giant corkscrew encased in a long, watertight tube that raised river water through its grooves by hand cranking. Most important was the noria-a chain of pots attached to a large wheel turned by tethered oxen marching in a circle-which had arrived with the Persian conquerors in the sixth century BC. Noria pots filled up through dipping in the river and emptied their water into a pipe or channel as they descended from the apex of their arc. In first millennium BC Egypt, a single noria could raise water as much as 13 feet and irrigate 12 acres of a second crop in the off-season. It was also used to drain swamps for reclamation. By raising and redirecting heavy and bulky water, water-lifting technologies increased irrigated cropland by as much as 10 to 15 percent through the Greek and Roman occupations. The noria was so successful that it remained in continuous use until the twentieth century and the advent of electric and gasoline pumps. The noria was the water-lifting precursor of the seminal waterwheel, a transformative innovation that automatically harnessed power from flowing stream to ground flour and drove the first industries.
The New Kingdom also derived great wealth from Egypt's full embrace of foreign sea trade. Egyptians had been one of the first peoples to regularly sail the shorelines of the eastern Mediterranean. Old Kingdom vessels had regularly sailed to Byblos to secure precious, high-quality timber-so scarce in tree-poor, rainless Egypt-from the fabled cedar forests of Lebanon, to make boats, plows, and other vital tools of civilization. Pyramid illustrations show that as early as 2540 BC they ferried soldiers to Levantine ports in square-sailed ships that were simple adaptations of the river vessels that plied the gentle winds and currents of the Nile. Yet only with the reuniting of Egypt in the New Kingdom did sea trade become much more extensive. The spirit of the age was expressed by Queen Hatshepsut, one of the rare Egyptian female sovereigns and the first important queen of ancient history. Shortly after the start of her twenty-year reign in 1479 BC, inspired by an oracle of the god Amun, Hatshepsut launched a maritime trading expedition via the treacherous Red Sea to restore trade with Punt in the Horn of Africa, which was one of the two sources in the ancient world for prized, exotic luxuries like frankincense and myrrh, used for religious ceremonies and embalming mummies. The expedition returned with live frankincense trees that were transplanted in the queen's gardens and inaugurated three centuries of thriving shipping and trade extending from Punt to the eastern Mediterranean. Cedars from Lebanon, copper from Cyprus, silver from Asia Minor, and fine crafts and Asian textiles arrived from the north. Invariably, Egyptian military campaigns in the Levant accompanied the increasing overlapping of economic interests. Yet although Egypt profited handsomely from this sea trade, it never transcended its Nile-centric legacy to also become a true Mediterranean maritime civilization. Light, oversized Nile boats never were built to venture far beyond the safe, known shoreline routes. To transship larger cargoes across the open waters, the Egyptians instead relied upon abler vessels and seamen from Crete, where the Minoans presided over the Mediterranean's first great seafaring civilization.
The Mediterranean provided the highway for three waves of raiders that began to attack Egypt at the end of the thirteenth century BC. The Sea Peoples were an eclectic collection of seafarers put to flight as refugees from their homelands by the invasion of Iron Age barbarians from inland mountains who disrupted Bronze Age civilizations throughout the Middle East. After about a century, following a campaign that included one of history's early naval battles, the Egyptians finally repelled the last of the Sea Peoples, whose allies, the Philistines, settled in Palestine and would soon engage in battle with the Hebrews, who had earlier fled Egypt under Moses in search of new lands. Ultimately, however, the cyclic ebbing of good Nile floods marked a century of internal disorder and disintegration, while history's ever-expanding geographic overlap of regional empires brought new waves of foreign invasions that ushered in the longest and bleakest of Egypt's intermediate periods. For nearly four centuries, Egypt was subjugated by foreigners. Libyans, Nubians, and, briefly, the fierce, iron-weapon-armed Assyrians put their imprint on the Nile and its lands.
A brief resurgence of native Egyptian rule occurred in the late seventh century BC. Under the ambitious Pharaoh Neko II (610595 BC), Egypt established a powerful navy, while its armies won battles and seized land in the war-torn Levant as far as the Euphrates River. Neko followed a policy of opening Egypt to the thriving Greek world and sea trade. He is most renowned in water history for excavating the first documented "Suez Canal," which he hoped would help Egypt compete in the Mediterranean. Neko's canal did not follow the same route from the Red Sea to the Mediterranean as the celebrated nineteenth-century canal. Instead, it connected the Red Sea to a branch of the Nile, and thus could unite Egypt's Mediterranean and Red Sea fleets of Greek-style galleys propelled by three banks of oars, known as triremes. It was dug wide enough to allow two vessels to pass each other. According to Herodotus, 120,000 died constructing it. Neko reportedly stopped work before completion when an oracle warned him that it would work to the advantage of his foreign enemies.
In fact, the canal was completed after the Persian conquest under King Darius I, who ruled from 521 to 486 BC, to facilitate shipping from Egypt to Persia. The new Hellenic dynasty of Ptolemies that assumed power after Alexander the Great's conquest hastened to dredge and extend the canal in the early third century BC. It was revitalized again in the early second century AD, under Emperor Trajan, during the height of the Roman Empire, but silted up under the Byzantines. The canal may have been opened and then later filled in by early Muslim rulers. In the early sixteenth century, the Venetians and the Egyptians discussed reopening the Red Sea to a Mediterranean connection in response to the Portuguese creation of the all-water spice trade route to India that broke the long, profitable Venice-Alexandria stranglehold on the region's trade with the East. But nothing came of it. Also fruitlessly, the Ottomans considered such a project during the sixteenth century; the sultan and the Christian king of Spain instead struck an armistice that allowed each side to focus its energies on fighting its own religion's heretics. Thereafter, the water link between the Red Sea and the Mediterranean remained closed until 1869, when the world-changing geopolitical and engineering marvel of the modern Suez Canal was opened to world commerce and naval forces.
Control of the Nile, and the caprices of its high and low floods, remained vital to the fortunes of all of Egypt's subsequent occupiers. The Greek and Roman overlords from Alexander's conquest in 332 BC to the fourth century AD, were blessed by good Nile floods and even rainfall, which facilitated an impressive expansion of cultivated land and intensified irrigation. For Rome, which took control in 30 BC, Egypt became the empire's export grain breadbasket, vital to maintaining its armies as well as the daily bread dole for Rome's legions of restive poor. The collapse of Byzantine rule to the Arab invaders in AD 640 followed a century of poor flooding. Three centuries of full Niles nourished Islam's heyday. Recurrent low Niles during the tenth to eleventh centuries, however, ultimately undermined the rule of the Fatimid founders of Cairo.
Due to its geostrategic centricity at a key crossroads of world commerce and politics, Egypt and its arterial river remained a pivotal theater in the struggle among the great powers through the centuries to modern times, including the nineteenth-century contest for global empire between England and France, and the twentieth-century Cold War between America and the Soviet Union over the Aswan Dam and regional influence in the oil-rich Arab Middle East.
Ancient Mesopotamia faced far more complex and adverse hydrological environmental challenges than those posed by the Nile. Yet even earlier than Egypt, it developed a hydraulic-model civilization that reflected the resources, cycles, and flow signatures of its flooding, silt-spreading twin rivers, the Tigris and the Euphrates, that coursed through the heart of the Fertile Crescent in modern Turkey, Syria, and Iraq. The rivers of Mesopotamia-which in Greek means "the land between the rivers"-helped create the ancient world's most precocious large civilization, featuring the wedge-shaped cuneiform that was mankind's first written language, the first large cities, sophisticated water-lifting and irrigation technologies, the wheel, towering spiral-shaped ziggurat temples, and dynamic, expansive empires.
Unlike the Nile, the twin rivers' distinguishing characteristic was that their floods spilled and receded unpredictably, often violently-and always out of rhythm with the needs of the farming cycle. When water was needed most, during autumn planting and plowing, the rivers were at their lowest. In the late spring, the nearly full-grown plants were imperiled with ruin from swollen rivers that flooded suddenly from torrential rainstorms of thunder and sheet lightning. Having two rivers with many branches complicated the hydraulics of the farming floodplain. Spillover from the higher yet slower-moving Euphrates, for instance, often drained easterly into the larger Tigris. Due to their shallow gradients, both rivers were prone to meander and, during big floods, to cut new courses to the sea, stranding existing cropland and entire communities of their life-giving water supply.
The key to civilization in Mesopotamia, therefore, rested upon skillful, year-round regulation of the twin rivers through extensive waterworks. Large reservoir dams stored water that was released in the growing season. Water was lifted to levels required to flood the furrowed fields. Strong protective dikes were needed to prevent flooding at the wrong time. A drainage network of sluices and diversion ditches was needed to combat waterlogging in the flat, poorly draining cropland. In short, if natural hydraulics made Egypt a gift of the Nile, Mesopotamia was an artificially contrived civilization whose success was achieved in defiance of the design of nature through the water-engineering ingenuity and willful organization of society.
In every way, Mesopotamia's material, social, and political existence was more volatile and uncertain than Egypt's. Instead of being protected behind a waterless desert barrier, its region was a natural crossroads of peoples, ideas, and goods, surrounded by potential raiders and rivals who lived in the rainy hills whose tributaries fed the twin rivers' plains. Extensive commerce and conflicts between city-states, and constant invasions by ever-larger empires, marked Mesopotamia's history. As the rivers' resources came under better control, moreover, political power tended to move upstream, where cropland was unspoiled and strategic command could be exerted over the rivers' unidirectional transport navigability and the region's water supply. "A society dependent on water coming from a canal that could be blocked several miles upstream from the fields it served was extremely vulnerable to warlike attack," writes historian William H. McNeill. "A position upstream was therefore always of supreme strategic importance in Mesopotamian politics and war, while downstream populations were always and inescapably at the mercy of whoever controlled the water supply." From Sumer in the fourth and third millennia BC to Akkad under Sargon I in 2334 BC, Babylon under Hammurabi in about 1792 BC, Assyria by 800 BC, and the Persians by 500 BC, the preeminent centers of Mesopotamian civilization moved generally upriver and its irrigation zone widened.