River Restoration. Группа авторов

of biodiversity and bioproduction in space and time; but, the constraints must be removed, not mitigated.” Downs and Thorne 2000, pp. 249–250 “It is now widely recognised that river restoration in the sense of Cairns (1991) – ‘The complete structural and functional return to a pre‐disturbance state’ – is seldom feasible.” “Practical ‘river restoration’ is, in fact, an historically‐influenced exercise in environmental enhancement through morphological modification. It is probably more accurate to refer to the approach as river rehabilitation.” McIver and Starr 2001, p. 15, citing SER website “Ecological restoration can be defined as ‘the process of assisting the recovery and management of ecological integrity,’ including a ‘critical range of variability in biodiversity, ecological processes and structures, regional and historical context, and sustainable cultural practices.’” Wohl et al. 2005, p. 2 “We define ecological river restoration as assisting the recovery of ecological integrity in a degraded watershed system by reestablishing the processes necessary to support the natural ecosystem within a watershed. Because both technical and social constraints often preclude ‘full’ restoration of ecosystem structure and function, rehabilitation is sometimes distinguished from restoration.” Palmer and Allan 2006, pp. 41–42 “River restoration means repairing waterways that can no longer perform essential ecological and social functions such as mitigating floods, providing clean drinking water, removing excessive levels of nutrients and sediments before they choke coastal zones, and supporting fisheries and wildlife. Healthy rivers and streams also enhance property values and are a hub for recreation.” Chou 2016, p. 2 “[R]iver restoration means different things to different people. In terms of scale and scope, it can be a complete structural and functional return to the pre‐disturbance state, a recovery of the partly functional and/or structural conditions of rivers (i.e., rehabilitation), a recovery of the natural state of a river ecosystem without really aiming at the pristine, pre‐disturbance state (i.e., renaturalization), or an improvement of the present state of rivers and their surrounding areas with the intention of enhancing their ecological, social, economic or aesthetic features (i.e., enhancement).”

      Adhering to Chou’s (2016, p. 2) assertion that “river restoration means different things to different people,” we adopt a relatively broad definition of restoration in this book. We do not distinguish between some commonly used concepts such as restoration, rehabilitation, renaturation, or revitalization actions. We consider as restoration any human intervention on the river aimed at recovering a quality considered degraded or lost. This quality can be perceived in terms of biodiversity, hydromorphological dynamics, physicochemical parameters, landscape beauty, or even the possibility of recreational use.

      According to Palmer et al. (2014), there has been a shift in ecological restoration from ecological theory to utilitarian concerns. This utilitarian approach to restoration is rooted in a more anthropocentric ethic, but paradoxically, it can also be instrumentalized to serve an eco‐centric ethic. The articulation of intrinsic and instrumental values is at work in restoration approaches (Clewell and Aronson 2006). It is reinforced by the ever more pressing need to justify often costly policies in the fluvial domain (e.g. Bernhardt et al. 2005; Nakamura et al. 2006; Brooks and Lake 2007). The ecological or hydromorphological quality of a river is no longer justifiable as an end in itself, but must appear as a necessity with regard to the services that the good state and biophysical functioning of a river can provide, or the risks burdening societies in the case of nonaction. This utilitarian vision is strongly based on the notion of services that has developed since the 1990s (Costanza et al. 1997). It finds particular resonance in the context of urban river restoration projects, which are highly constrained socially, politically, and technically (Eden and Tunstall 2006; Bernhardt and Palmer 2007). Moreover, it is largely in the context of urban ecology that the concept of “novel ecosystems” emerges, which requires consideration of the hybrid character, both natural and artificial, of the rivers to be restored (Francis 2014). The specificity of restoration in relation to other management approaches can also be called into question, as Elliot (1982, p. 81) anticipated when he denounced “faking nature.” Thus, there is a strong proximity between Martin’s (2017) proposed definition of ecological restoration, considered as “the process of assisting the recovery of a degraded, damaged, or destroyed ecosystem to reflect values regarded as inherent in the ecosystem and to provide goods and services that people value” and Mitsch’s definition of ecological engineering (2012, p. 5): “defined as the design of sustainable ecosystems that integrate human society with its natural environment for the benefit of both.”

      No matter how you look at this evolution, it has certainly increased the attention paid to societal issues in the field of restoration. Research in the humanities and social sciences has contributed to this evolution by proposing new methods to measure the socioeconomic benefits that societies derive from restoration projects and also by analyzing the sociopolitical processes at work in the implementation of projects. If the objectives of restoration are no longer guided solely by a scientific conception of reference states, but also in response to political choices concerning what rivers should be, a new space for debate is opened up, particularly in respect to the questioning of decision‐making. To the questions “Why are we restoring?” or “What are we restoring?” is added the question “Who is restoring for whom?” The work carried out in political ecology shows that new relationships of power are being established within the frameworks for implementing restoration projects. As much as the objectives of restoration, it is the political mechanisms leading to the definition of these objectives that are at the heart of debates. Work on participation is essential, and questions the place of scientific and technical expertise as much as that of other interests, be they economic or more simple public interests.

      1.1.3 What do we know about research on societal issues in the field of river restoration?

      Although several reviews highlight the increasing place of societal issues within the scientific work devoted to river restoration (Bennett et al. 2011; Smith et al. 2014; Wohl et al. 2015), none of them has focused on a specific analysis of this research field. This introductory chapter offers this analysis; without claiming to be exhaustive, it gives a broad overview of the dynamics at work on the societal stakes of river restoration.

      1 What is the magnitude of these dynamics? How are they structured at the international level? The first part of the introduction looks at the way the scientific community is organized within the field. Particular attention is paid to the way in which the work carried out by this community fits within the dynamics of general research on river restoration, but also within work in human and social environmental sciences.

      2 The second part then analyzes the main directions taken by researchers working on societal issues of restoration. What are the main problem areas that structure this field of research? In which disciplines or epistemological traditions are they rooted? What are the methodological approaches mobilized in the frameworks of the different projects?

      3 Finally, the third part is devoted to the operational commitment of researchers working on societal themes. Do these researchers support the implementation of river restoration projects and policies and, if so, how?

      The literature review that we present here is based on a qualitative and quantitative analysis of the body of international scientific articles devoted to river restoration. This body of literature was retrieved from a search of the titles of articles listed in the Web of Science (WoS) using the keywords river*, stream*, restor*, rehab*, renat*, and revit*. In total, this search identified 1677 articles published between 1971 and 2019 by authors from about fifty different countries. The content of these 1677 articles was analyzed and a subset of 121 publications