The transition from sail to steam shipping shaped the later-nineteenth-century Port of London. When limited to river trade and traffic, steamers had little effect on facilities. Once improvements in technology extended the economic viability of steamers on ever more distant passages, larger and deeper docks were needed. This led to existing facility improvements and downstream docks. The new steam port, served by major shipping lines, depended on barge transhipment of cargoes to waterfront wharves, which flourished as a result. Trade volumes responded to metropolitan population growth, but the national share remained stable or fell. Wool and grain replaced sugar as leading trades. Re-export business declined. The capital’s relationship with the port changed. In the 1860s, its perceived importance led to the rejection of an eastern Thames embankment. In the 1880s, Tower Bridge went ahead.

Worldwide, freshwater biodiversity is in decline and increasingly threatened. Fishes are the best-documented indicators of this decline. General threats to persistence include: (1) competition for water, (2) habitat alteration, (3) pollution, (4) invasions of alien species, (5) commercial exploitation and (6) global climate change. Regional faunas usually face multiple, simultaneous causes of decline. Threatened species belong to all major evolutionary lineages of fishes, although families with the most imperilled species are those with the most species (e.g. Cyprinidae, Cichlidae). Independent evaluation of California’s highly endemic (81%) fish fauna for comparison with IUCN results validates the alarm generated by IUCN evaluations. However, IUCN overall evaluation is conservative, because it does not include many intraspecific taxa for which extinction trends are roughly double those at the species level. Dramatic global loss of freshwater fish species is imminent without immediate and bold actions by multiple countries.

Hydropower is the largest source of renewable energy in the world; it is expected at least to double by 2050. This chapter reviews how benefits from hydropower can be maximised while reducing environmental and social impacts. The scope for expansion of hydropower is considerable, but adverse environmental and social impacts need to be managed. Climate change is impacting hydro generation through changed snow melts and river flows, greater evaporation and more frequent extreme events, such as flooding and droughts. Hydropower infrastructure needs to have margins to cope with extreme events and adapt to changing conditions. Relicensing at specified intervals can provide a framework for renovation, removal or changes to minimise impacts and maximise benefits of dams. Planning of dams needs to be undertaken on a whole-of-river-basin scale . The World Commission on Dams (2000) recommended priorities for more sustainable development. The Hydropower Sustainability Assessment Protocol is one codification of better hydropower development practices. Hydropower is important in providing storage and firming capacity to complement intermittent generation from solar and wind generators.

This chapter profiles contemporary examples of ecosystem collapse and recovery. Case studies presented include coral reefs, marine fisheries, freshwater ecosystems (streams, rivers and lakes), forests (including tropical, temperate and boreal), savanna, and temperate agroecosystems. In each case, the available empirical evidence is reviewed in relation to the ecological mechanisms underlying both ecosystem collapse and recovery. At the end of the chapter, the theoretical propositions identified in Chapter 2 and refined in Chapter 3 are then evaluated in the light of the evidence available from these contemporary case studies.

This chapter explores the early twentieth-century phenomenon known as the roman-fleuve (river-novel) and proposes a model for understanding its place within French literary history. The origins of the term can be traced back to Romain Rolland’s Jean-Christophe, a multi-volume novel recounting the fictional life story of its eponymous protagonist. Although there are notable stylistic and thematic differences between it and the novel cycles of the other three proponents of the roman-fleuve form—Roger Martin du Gard, Jules Romains, and Georges Duhamel—Jean-Christophe provides the yardstick against which these later literary creations must be measured. Utilizing Rolland’s protagonist as its central reference point, the chapter contends that the roman-fleuve’s overarching ambition is to rework the notion of the modern subject in function of an alternative understanding of the individual and the collective. In a tumultuous era marked by war and the crumbling of religious and metaphysical certainties, this reconception of subjectivity inaugurated an innovative literary exploration of Bergsonian intuition and the Nietzschean overturning of ready-made systems of thought. Lying between the sentimentality of the romantics and the materialism of the positivists, the roman-fleuve was a landmark, if short-lived, example of French literary creativity blossoming in the arid ground of modernity.

This introductory chapter discusses what a river is; why rivers are important, both as natural features that shape the Earth’s surface and as resources for society; the science of fluvial geomorphology, including a brief history of this field; the process-oriented perspective of the book; rivers as dynamic natural systems; general concepts, such as dynamic equilibrium, thresholds, and nonlinear system dynamics, that have been employed to describe the dynamics of river systems; and the importance of both physical processes and environmental/historical contingency as factors influencing the dynamics of river systems. It presents a conceptual model defining rivers as dynamic systems characterized by interaction among flow, sediment transport, and channel form. It defines a hierarchy of spatial and temporal scales relevant to the characterization of river systems.

This chapter considers the development of drainage basins and stream networks over geological timescales. It examines why a focus on river systems over geological timescales is important, how river channels form through surface and subsurface processes, and the differences between stream channels and hillslope erosional features, such as rills and gullies. It explores how drainage networks are related to properties of drainage basins and how stream networks develop, grow, and evolve over time. It also examines how channels are initiated on the landscape and how drainage-basin evolution and channel network evolution are intertwined. The spatial geometry and arrangement of river networks is reviewed along with the scaling properties of these networks.

This chapter examines how rivers respond to human impacts. It introduces the concept of the Anthropocene, the notion that society has produced a new geologic epoch dominated by human change of the environment, as the context for discussion. A distinction is made between indirect impacts on rivers, which involve changes in land cover or climate, and direct impacts, which involve human modification of river channels. Cycles of erosion and deposition within river systems are discussed in relation to land clearing, implementation of agriculture, different stages of urbanization, and hydraulic mining. The potential impacts of climate change on rivers are also explored. Direct impacts on rivers include channelization, construction of dams, and in-channel mining. The ways in which direct and indirect human impacts on rivers lead to transient geomorphological responses are explored through the concepts of the channel evolution model and aggradational-degradational episodes.

This chapter reviews in detail the dynamics of anastomosing and anabranching river systems. The difference between anastomosing and anabranching rivers as well as the difference between anastomosing/anabranching and braided rivers is outlined in detail. Anastomosing rivers are examined as a distinctive form of low-energy fluvial systems and of the world’s largest rivers. Anabranching is introduced as a generic type of multichannel river form of which anastomosing is a distinct subcategory. Mechanisms of avulsion, the key process associated with dynamic change of anabranching rivers, are reviewed. The dynamics of wandering gravel-bed rivers, a distinctive type of anabranching river, are explored along with examples of other types of anabranching systems, including those in dryland environments.

This chapter focuses on river confluences as a distinctive type of river planform. Topics covered in the chapter include the characteristics of confluence planform geometry, the distinction of confluence types based on planform symmetry, the factors controlling flow structure and patterns of sediment transport in confluences, current understanding of flow structure and patterns of sediment transport in confluences, dynamic changes in bed morphology in relation to changes in hydrological conditions of incoming flows, mixing downstream of confluences, changes in channel geometry at confluences, and changes in confluence planform over time.

This chapter return to the soteriological arc with a discussion of sacramental imagery and aspirations of redemption and transcendence. Beginning with the Gaudete Epilogue poems and moving on River and Under the North Star, it looks at the rise in sacramental and specifically eucharistic imagery in Hughes’s poetry, arguing that the naturalization of sacramental activity in these poems authenticates human religious concerns. Sympathies between Hughes’s work and that of the American Transcendentalist, hinted at here there so far in the book, are discussed explicitly. Also making significant reference to Eliot, this chapter discusses the question of time in Hughes’s poetry, where, especially in River, it appears as something to be resisted and potentially escaped or transcended. The chapter culminates in a close reading of the poems “That Morning” and “The River.” We watch as Hughes overcomes anxieties about the destructive nature of time by cleaving ever closer to an explicitly Christian metaphysic.