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This chapter provides an overview of how satellite remote sensing can help map the occurrence, and risk of occurrence, of several environmental disturbances; assess the extent of the associated damages; and monitor the recovery of the areas impacted by these disturbances. It particularly focuses on floods, wild fires, droughts, frost, extreme winter warming events, infestations and blooms, and bleaching events, as these are all well-known natural disturbances likely to change in frequency of occurrence and intensity over the coming decades. Through the use of examples, this chapter demonstrates how the utility of satellite remote sensing resides in the ability it provides to separate and characterise (i.e. through form, intensity, and trajectory) disturbances and responses at various spatial and temporal scales, thereby facilitating ecological knowledge expansion and the identification of relevant management actions. In particular, this contribution shows how satellites offer multiple opportunities to gain accurate information on the location, spatial extent, and duration of disturbances at the continental scale, which is needed to evaluate the ecosystem impacts of land cover changes due to, for example, wild fire, insect epidemics, and flooding, thereby reducing uncertainties in our ability to model global carbon budgets.

For millennia, humans have been dependent upon rivers and their resources for food, transport, and irrigation, and by mid-Holocene times (about 5,000 years ago), humans harnessed hydraulic power that in part contributed to the rise of civilization. It is generally accepted that the earliest civilizations to develop such linkages with irrigation and cultivation of crops arose in the Old World, in Mesopotamia and the Levant, the Indus Valley, and the Central Kingdom, associated with, respectively, the Tigris, Jordan, Euphrates, and Nile; the Indus; and the Huang He (Yellow) and Changjiang (Yangtze) rivers—and, of course, their associated deltas. In this chapter, I examine the role of selected coastal deltas that were important in the development of these early Old World civiliza­tions, and how those people began to alter the shape and character of the highly productive and constantly changing deltaic environments. Before we begin, how­ever, I need to provide some basic definitions. First, I use the definition of civilization provided by Hassan, “a phenome­non of large societies with highly differentiated sectors of activities interrelated in a complex network of exchanges and obligations.” Second, I use the defini­tion of delta presented by Overeem, Syvitski, and Hutton, “a discrete shoreline protuberance formed where a river enters an ocean or lake, … a broadly lobate shape in plain view narrowing in the direction of the feeding river, and a sig­nificant proportion of the deposit … derived from the river”. Although I will at times discuss linkages between development of human settlements and river reaches upstream from the coastal delta, my primary focus in this chapter is on coastal deltaic regions, in particular those of the Nile, Indus, Yellow, and Yangtze rivers, which provide the best examples for link­ages between relatively recent early human populations and coastal deltas. I will address other deltas later in the book. My rationale for beginning this book with a discussion of the relationship between Old World civilizations and deltas is that this long- term interaction has been so dramatically altered over the past few millennia— essentially, it is a good relationship “gone bad.”

As human populations have increased on the planet, so have their effects on the natural landscape. When human-engineered changes in the movement of soils and rocks occur in the vast watersheds of major rivers, they can have dramatic consequences with respect to the amount of sediment needed to “feed” and support large river deltas at the coast. Many of the largest effects of human activity on the surface of the earth have occurred recently—in the past 200 or so years—and they have been so dramatic it has been argued it is time to create a new epoch in the Geologic Time Scale, one called the Anthropocene. That suggestion is being considered seriously. Nevertheless, the first alterations of the landscape began as early as the Paleolithic, approximately 400,000 to 500,000 years ago, when our human-like ancestors Homo erectus are believed to have begun altering the natural landscape with simple dwelling structures. As humans evolved, so did the tools they used, from sticks and animal antlers to wood and iron plows. Although modern humans (Homo sapiens sapiens) had developed in East Africa by about 200,000 years ago, their ability to extensively modify the landscape through agricultural activities did not likely happen for another 120,000 years. Incredibly, there was a rise in agricultural communities about five millennia ago that seems to have occurred simultaneously, yet independently, in six different regions of world (see Chapters 1 and 2 for linkages among human civilizations, deltas, and stabilization of climate in the Holocene). After the invention of the wheel in the middle Holocene, it became much easier to perform earth-moving activities. This was followed by the Iron Age, around 2,500 years ago, during which iron replaced earlier, less efficient copper and bronze tools for moving earth. Amazingly, the first man-made canal, connecting the Mediterranean and Red seas, was constructed before the Iron Age, around 3,600 years ago. Today, humans are the most effective animals on the planet with respect to altering Earth’s surface, and the use of machinery enables earth-moving activities, such as strip- mining, for extraction of valuable mineral resources like copper and silver.