Chapter 1 of Earthopolis: A Biography of Our Urban Planet elaborates on both the myth of Inanna’s chaotic riverboat journey to Uruk and the vision of the goddess’s ordered urban state depicted on the Warka Vase to meditate on the many birthplaces and birthdates of cities and their surrounding “urban worlds.” It identifies river valleys (and other Sun and Earth-delivered sources of fresh water) as crucial to our ability to harvest enough energy from the Sun and Earth to build cities and it discusses the importance of “energized crowds” that arise in large, proximate, specialized, diverse, and anonymous settlements. Ultimately, though, the chapter argues that urban political communities and the especially powerful institutions of state required to govern them best account for cities' ultimate indefinability: their sheer variability and the sheer unpredictability of their human uses, ranging from immense acts of creation to immense acts of destruction. Cities, it concludes, are places where we harvest enough energy from the Sun and Earth, through water, to engage in the ambitious and dangerous human-directed practice of city-enabled politics – the polis of Earthopolis, the only Urban Planet we know of.

The Sultanate's political economy evolved continuously. Since the regime presided over an imperial union of territories that differed in their topography and ecology, the process of evolution in these regions exhibited contrasting patterns of change. Agriculture in the Nile Valley manifested procedures unlike crop raising or animal husbandry along the Syrian coast, upland valleys or semi-arid outback of the Syrian Sahel. Commodities imported from South or East Asia transited from ports in Yemen or Western Arabia through entrepôts on the Upper Nile to Alexandria, where they were transferred to European carriers that conveyed them to destinations on the Mediterranean north shore and beyond. Agents in each of these stages answered to differing sponsors, aligned their conduct of business with local politics and extracted revenues at levels fluctuating within the mechanisms that governed inter-regional trade throughout this period. Domestic commerce in both urban and rural settings dealt in the exchange of commodities produced locally in a workshop milieu. Control over (and profiteering from) marketing of lucrative staples that funneled revenues to the regime, such as spices, textiles or sugar, became a principal objective of governmental authority, with results that enhanced the Sultanate’s fisc in the short term but compromised its competitive position in the longue durée. These issues are considered from the perspective of agriculture or animal husbandry in Egypt and Syria, the varying extent of control exercised over them by the bureaucracy, interregional trade and its manipulation by the Sultanate over time, the domestic commercial economy, and finally the overt expropriation or clandestine extraction on which the regime relied as licit sources of revenue diminished in the Sultanate’s final century.

Research has proliferated on several topics that have invited new methodological approaches: the rural setting, gendered relations between men and women, communal status of minorities (Christians and Jews), and religious diversity among Muslims, in particular among those who identified as Sufi mystics. New sources and revisionist interpretations of them continue to transform the field of Mamluk Studies. Yet in many instances, findings on these subjects are confined to discoveries of information on discrete conditions or isolated events that do not lend themselves to comprehensive analysis. They often depend on a single source or fragmentary data set, and require imaginative speculation to formulate hypotheses that apply to questions about their broader contexts in society. The chapter will outline the state of research on these subjects and their potential to open new lines of inquiry by highlighting examples that have influenced revisionist interpretations.

China is one of the seven regions in the world where agriculture developed independently, and among the earliest, with cultivation of cereal crops dating back to at least 7000 bce. The unique repertoire of crops first cultivated in China – millet, rice, and soybeans – remained staple foods throughout Chinese history, although millet was mostly displaced by wheat, an import from West Asia, by 1000 ce. The long history of the development of agriculture and the rise of cereal cultivation as the mainstay of human livelihood and economic activity dramatically altered the natural landscape, its landforms, soils, and waters as well as its flora and fauna. Domestication of the environment to serve human needs for food, clothing, shelter, and fuel repeatedly realigned the balance between human populations and natural resources. The strain of burgeoning human populations and their demands on these resources necessitated continual technological innovation to sustain agricultural production and conserve natural resources. By the year 1000 the human impact had utterly transformed the ecology of northern China, especially in the watershed of the Yellow River.

Intricate relations between people, animals, and plants were the basis of the entire imperial Chinese order no matter what dynasty was ostensibly in charge. Such relations were environmental in the sense that they formed interdependencies between species under diverse ecological conditions of climate and topography. The most significant environmental historical result of these relations for the eight centuries under study here was agriculture, the main source of China’s human-induced (or “anthropogenic”) ecological change. An extended, instructive example of the intricacies of farming’s requisite resource management comes from the Ming (1368–1644) town of Pingwang in the Yangzi delta, likely the most developed area of contemporary imperial agrarian practice.

The chapter traces the rise from the distant pre-contact past of the modified lake environment through the Post-Classic Period when the Native American peoples founded their altepetl, or city-states, until their conquest first by the Aztec Triple Alliance and then by Spaniards. The chapter covers the Spanish--Mexica War and demonstrates that it had vital a hydraulic dimension. While the siege of Tenochtitlan has long been understood as a naval battle, the analysis presented here follows the precedent of the New Conquest History in underscoring the contributions of Nahuas to the outcome of the conflict, particularly when it came to specialist knowledge of the Basin of Mexico’s hydrology and strategic efforts to defeat the enemies by turning the engineering works against them. The chapter concludes by tracing continuities into the mid-sixteenth century, especially with the survival of the altepetl and its foundation for colonial-era jurisdictions, including that of the cabildo, or town council, which Nahuas readily adopted and made their own. In so doing, they preserved control over the water management system even as they adapted to new colonial realities.

The Jucar Basin faces the challenge of meeting an enormous demand for irrigation while water quality degrades from urban, industrial, and agricultural pollution. Relying on engineering solutions is not enough. Empirical evidence in Jucar indicates that water markets and institutional policies seem to deal with water scarcity more successfully than water pricing and irrigation subsidies. A first water governance priority is to convince farmers of substituting freshwater for the available urban recycled water. Second, seawater desalination plants must be upgraded so they will work at full capacity. More long-term governance goals are to curtail surface irrigation diversions and groundwater extractions, and reallocating water to urban, industrial, and environmental uses. These reforms will only work if they get the support and cooperation of farmers by compensating them for the reallocation of water from agriculture to other sectors.

The Yellow River is by its nature not sustainable since it carried the world’s heaviest silt load for a long time. Yet, this silt load (loess plateau) has fallen considerably in recent years, but at the cost of other forms of sustainability, such as streamflow. The reasons for this dramatic decline in runoff are complex. In addition to reducing silt load, terraces and vegetation have led to the marked reduction in runoff. The fall in natural runoff can also be attributed to groundwater and mining extractions, as well as reservoir filling. Population per se is not a major driver of water demand compared to irrigated agriculture and other sectors, notably mining and industry. While China is not a federal system, it is organized in a complex hierarchical system where provinces play an important role and are capable of serving their own interests in negotiating usages and allocations of the river. The chapter analyzes peculiar physical conditions and water management institutions in the Yellow River Basin.

Water rights and water market mechanisms are key characteristics to describe water management and allocation in the Limarí Basin in Chile. The 1981 Water Code strengthens private water use rights and declares them freely tradable. Engineering infrastructure, climatic conditions, and institutional capacities in terms of tradable water rights and private water user associations allowed economic development in the Limarí Valley. However, the lack of governmental regulation has led to overexploitation of water resources threatening water security, such as environmental and agricultural sustainability. In the face of climate change and decreasing water availability, the current infrastructural and management system requires reforms.

This chapter discusses both the role of irrigation in river basin development and closure and how its share in total water use can be reduced. It first briefly outlines the importance of unchecked irrigation development in the growing share of water consumption and the closure process of the basins examined in this volume. This understanding of how irrigation came to play a peculiar role in river basin development is important for discussing how its share can be reduced. The chapter recalls the diversity of policy options available to respond to imbalances between supply and demand and that supply augmentation is generally favored. Finally, the chapter focuses on the issue of "water savings," documenting various responses by the irrigated sector to shortages and exploring how policies to modernize irrigation technologies may inadvertently contribute to enhancing evapotranspiration and therefore undermine purported conservation objectives.

The farmers who domesticated and grew rice throughout history developed expert knowledge that successfully allowed them to operate farming systems that are the most productive in terms of calories per hectare worldwide. Throughout both the historic and prehistoric record, Asian rice farmers have developed a dazzling array of techniques to deal with the climatic variations and changes in sea level and river evolution. Southern China is less impacted by changes in rainfall and precipitation than Northern China or South Asia. Humans have, however, constructed a unique niche for this aquatic plant, moving it into areas well outside of its natural range. This chapter outlines how humans first domesticated rice and controlled rivers and mastered the irrigation systems that support it.

This chapter reviews the spread of irrigation technology across the Sahara in antiquity, and its effects on settlement agriculture and the movement of people. Recent work has stressed the close connections between the introduction of foggara technology and the rise of Garamantian civilisation, which featured intensive agriculture and incipient urbanism. However, many oases achieved substantial size through the use of well technologies, artesian springs or a combination of technologies. Another key question relates to the effects of the eventual decline and failure of these irrigation systems in terms of population movement and fragmentation of states such as the Garamantes. After presenting new AMS dating evidence for Garamantian foggaras, the chapter advances the discussion by examining the wider picture of foggara distribution within a survey of the evidence of irrigation technologies across the Sahara and whether and to what extent the distribution of foggaras beyond the core Garamantian heartlands might be seen as an indication of Garamantian control or influence. It explores what foggaras, wells and new crop introductions might suggest about agricultural intensification and organisation. This has implications for assessing agricultural intensification in the ancient Sahara. Finally, it considers causes and possible effects of irrigation failure and in some cases collapse.