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Yolo Bypass floodplain and view of downtown Sacramento, 2007 (courtesy of California Department of Water Resources).
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Conventional flood control has emphasized structural measures such as levees, reservoirs, and engineered channels—measures that typically simplify river channels and cut them off from their floodplain, both with adverse environmental consequences. Structural measures tend to be rigid and not easily adapted to increased flooding regimes resulting fr...
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The U.S. Army Corps of Engineers (USACE) is one of the world’s largest public engineering, design, and construction management agencies. The major Civil Works (CW) mission areas include navigation, flood risk management, hydropower, ecosystem restoration, coastal storm damage reduction, hydropower, water supply and recreation. To capture the region...
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... Firstly, hydrogeomorphology allows a better preliminary understanding of a river system, its trajectory and its degradation Fryirs, 2015;Grabowski et al., 2014;Mould & Fryirs, 2018). Secondly, that understanding guides an evaluation of the river's restoration potential, to frame which uses and human benefits are reasonable to expect in the system, and which are not (Auerbach et al., 2014;Gilvear et al., 2013;Serra-Llobet et al., 2022). Finally, it is crucial for monitoring the results and repercussions of a project . ...
Integrating hydrogeomorphological (HGM) principles into the restoration of degraded rivers can achieve sustainable results and provide various human benefits. HGM principles mainly involve understanding the context and processes that shape a fluvial system before any intervention, in order to support its dynamism and to align with its potential functioning and uses. Despite recent management approaches inspired by HGM principles, most restoration projects carried out in Quebec (Canada) are not process‐based and target specific one‐dimensional objectives. Although there is an overall lack of post‐project monitoring, several projects appear to have failed or had mixed success. This research aims to shed light on the diversity of societal drivers behind river restoration projects and to examine how they influence the integration of HGM principles and human benefits. Four restoration projects were characterized through participant observation and interviews with the organizations running them. Representatives of two ministries involved in river restoration and management were also interviewed. The results show that projects were mainly shaped by public acceptance disregarding HGM principles, which can lead to poorly‐informed action. Project funding and stakeholders' expertise have also challenged project implementation and played a key role in defining their objectives. The addition of these components improve the current analytical frameworks for identifying river restoration objectives. Depending on specific sociocultural, political and legislative contexts, funding programs and stakeholders' expertise may either facilitate or restrict the integration of HGM principles and human benefits in the projects. Recognizing these key drivers reframes river restoration as a fundamentally social activity and enlightens how they could impel innovative approaches towards more sustainable results.
... In disrupting river-floodplain dynamics, levees impact many floodplain functions including, fluxes of water, solutes, sediment, spatial heterogeneity of habitat, habitat abundance, and biodiversity (Poff et al., 1997;Knox et al., 2022a;Knox et al., 2022b). As the understanding of the importance of the physical, biogeochemical, and ecologic function of floodplains improves, there is increasing interest globally in the reconnection of floodplains to their rivers to maximize both ecological and societal benefits (Erős and Bányai, 2020;van Rees et al., 2021;Serra-Llobet et al., 2022). ...
... The reconnection of levee-protected floodplains to the river can restore the surface-water connectivity, which creates opportunities for reducing flood risk, increasing nutrient retention, habitat, and consequently improve ecosystem health within the river corridor (Opperman et al., 2009;Jacobson et al., 2015;Guida et al., 2016;Dahl et al., 2017;Serra-Llobet et al., 2022). While previous studies have attempted to quantify these potential benefits via hydraulic, flood loss, and ecological modeling (e.g., Sparks et al., 2003;Dierauer et al., 2012;Jacobson et al., 2015;Guida et al., 2016;Jacobson et al., 2022), there have been very few studies undertaken from which to directly measure reconnection benefits (Serra-Llobet et al., 2022) or their hydraulic, geomorphic, and sediment-transport effects on the river and its floodplain. ...
... The reconnection of levee-protected floodplains to the river can restore the surface-water connectivity, which creates opportunities for reducing flood risk, increasing nutrient retention, habitat, and consequently improve ecosystem health within the river corridor (Opperman et al., 2009;Jacobson et al., 2015;Guida et al., 2016;Dahl et al., 2017;Serra-Llobet et al., 2022). While previous studies have attempted to quantify these potential benefits via hydraulic, flood loss, and ecological modeling (e.g., Sparks et al., 2003;Dierauer et al., 2012;Jacobson et al., 2015;Guida et al., 2016;Jacobson et al., 2022), there have been very few studies undertaken from which to directly measure reconnection benefits (Serra-Llobet et al., 2022) or their hydraulic, geomorphic, and sediment-transport effects on the river and its floodplain. ...
... Beyond these agroecological solutions, the direction of land use change needs to be turned back on the so-called marginal lands via combined land use solutions (e.g. agroforestry and cultivation of periodically inundated areas Opperman et al. 2009;Serra-Llobet et al. 2022), and restoration of reclaimed ecosystems (IPCC 2019; European Commission 2020), and degraded lands (Arneth et al. 2021)). In this context, one of the most critical ecosystems is wetlands, since the area loss of natural wetlands is exceptionally large across CEE countries and wetlands were converted primarily to croplands (Fluet-Chouinard et al. 2023), especially in Hungary, where 97% of the wetlands, which covered an estimated one-third of the plains, were converted into agricultural areas (Schleupner and Schneider 2012;Nemeth et al. 2021). ...
Central and Eastern Europe (CEE) is a pillar of global wheat and maize production. However, certain areas within the CEE region have become climate change hotspots, experiencing intensifying water deficits and drought pressure, rising mean and maximum temperatures. This study focuses on the long-term statistical relationships between climatic factors and rain-fed wheat and maize yields for different landscape types in Hungary over 30-year time windows between 1921 and 2010. The relationship between the variances of the detrended climatic parameters and crop yields was tested employing both simple and multifactorial linear models according to landscape types and periods. The sensitivity of wheat yields to spring-summer mean temperature shifted dynamically from the western part of the country to east (from cooler and wetter hilly landscapes to plains) between the periods 1921-1950 and 1981-2010. The cooling observed in summer temperature between the periods 1921-1950 and 1951-1980 supported an increase in wheat yields by an estimated 0.11-0.43 t ha −1 year −1 , while the 0.9-1.2 °C warming of May-July temperature may have cut wheat yields by an estimated 0.44-0.56 t ha −1 year −1 in various regions over 1981-2010. That being said, the regional sensitivity of wheat yields to May-July mean temperature did not display substantial differences between the periods 1921-1950 and 1981-2010. Besides negative effects, climate change had a positive impact on wheat yields, since increasing January-March mean temperatures mitigated the negative impact of warming summer temperatures on wheat yields by an estimated 16-34% over 1981-2010. In this 30-year period, increasing mean temperature together with decreasing precipitation explained 46-75% of the variances in maize yields reducing annual maize harvests by an estimated 11.1-12.4% year −1 .
... To manage conflicts in barrier removal activities and the implementation of e-flows, we propose using a negotiation process similar to the holistic approaches used in water-scarce regions. This includes establishing flow requirements and comprehensive water planning to ensure sustainable water use and ecosystem restoration (e.g., Jumani et al. (2023); Serra-Llobet et al. (2022); Arthington et al. (2023)). ...
The EU Nature Restoration Law represents an important opportunity for freshwater habitat restoration and, consequently, freshwater biodiversity protection. However, a number of challenges must be anticipated in its implementation, which may compromise its success. Some aspects, particularly those relating to freshwater ecosystems, require more clarification. We use riverine ecosystems to illustrate existing ambiguities in the proposed legislation and the potential consequences of leaving these aspects open to interpretation during the implementation process. We also discuss potential solutions to these problems which could help ensure that the law's objectives are met. We argue that river network structure and connectivity dimensions, which result into river meta‐ecosystems, must be explicitly considered. For that purpose, we ask for clear definitions of the critical terms “free‐flowing rivers,” “barriers,” and “reference areas.” In addition, we recommend developing methods for integrated assessment of connectivity across river networks. As a key property of river ecosystems, this must be used to prioritize actions to increase the length and number of free‐flowing rivers. Adequate restoration planning at larger spatial scales will benefit from a meta‐ecosystem perspective and accurate representation of aquatic‐terrestrial linkages, which will significantly improve the efficacy of restoration efforts. Furthermore, stakeholder and citizen engagement offer important opportunities at local, national, and European scales, and should be fostered to ensure inclusive decision‐making. The conservation challenges outlined here are particularly important for rivers, but they also have implications for other ecosystems. These considerations are useful for policymakers, conservationists, and other stakeholders involved in the Nature Restoration Law and related policy initiatives.
This article is categorized under: Water and Life > Stresses and Pressures on Ecosystems
Water and Life > Conservation, Management, and Awareness
Human Water > Water Governance
... The use of evidence-based approaches in river restoration (Friberg et al., 2016) and in particular the integration of HGM principles (Beechie et al., 2010;Brierley & Fryirs, 2022;García et al., 2021;Piégay et al., 2023) are also recognized to enhance the sustainability of outcomes, for a variety of objectives and human benefits (HB) that are consistent with the potential functioning of rivers as well as their uses Gilvear et al., 2013;Serra-Llobet et al., 2022). Firstly, it allows a better preliminary understanding of a river system, its trajectory, degradation, and restoration potential Fryirs, 2015;Grabowski et al., 2014;, and secondly, it is crucial for monitoring the results and repercussions of a project . ...
Face aux détériorations historiques des géosystèmes fluviaux, la restauration de cours d'eau vise à diminuer leur dégradation et à améliorer leur qualité, dans le but de réhabiliter leurs fonctions et d'obtenir les bénéfices humains qui reposent sur ces dernières. L'intégration des principes de l'hydrogéomorphologie (HGM) dans la restauration de cours d'eau permet de définir des objectifs diversifiés, réalistes et cohérents avec le système fluvial, ainsi que d'atteindre des résultats plus durables. Malgré l'émergence récente d'approches de gestion inspirées par ces principes, l'HGM est très peu considérée dans la gestion des cours d'eau québécois, ce qui mène souvent à leur artificialisation ou à l'échec des actions de restauration. L'objectif principal de ce mémoire est d'identifier les défis d'intégrer les principes de l'HGM et une diversité de bénéfices humains dans les projets de restauration de cours d'eau réalisés au Québec et se divise en trois objectifs spécifiques : (1) analyser la structure opérationnelle et les processus décisionnels des projets, (2) caractériser leur niveau d'intégration des principes de l'HGM et d'une diversité de bénéfices humains et (3) identifier les défis de les intégrer aux projets, du point de vue des organismes qui les réalisent. L'atteinte de ces objectifs repose sur la documentation de quatre projets de restauration de cours d'eau selon une approche qualitative consistant en de l'accompagnement et des entretiens avec les organismes responsables des projets, ainsi que des ministères impliqués dans la gestion et la restauration des cours d'eau. Les résultats identifient deux facteurs limitants l'intégration de l'HGM dans les projets et une diversification des bénéfices humains qu'ils ciblent : le financement des projets et l'expertise des organismes qui les réalisent. Un nouveau cadre conceptuel est proposé afin d'intégrer ces composantes et de souligner l'importance des contextes socioculturels et législatifs. Ces perspectives ancrées dans la sociogéomorphologie promeuvent une réglementation ancrée dans les connaissances sur la dynamique des cours d'eau, un partage de connaissances accru entre les milieux scientifiques et les organismes en charge des projets de restauration de cours d'eau, ainsi que la collaboration entre ces derniers et les communautés qui cohabitent avec les cours d'eau. https://semaphore.uqar.ca/id/eprint/2933/
... Firstly, conventional flood risk management mostly depends on structural measures to reduce the impact of floods, rather than using comprehensive strategies like expanding river capacity and restricting development in flood-prone areas [27]. Practically, the implementation of structural solutions such as levees, dams, and built channels promotes the growth of urban and agricultural areas on floodplains, as it instills the belief among the public that the danger of flooding has been diminished [28]. ...
Flooding has always been a huge threat to human society. Global climate change coupled with unsustainable regional planning and urban development may cause more frequent inundations and, consequently, higher societal and economic losses. In order to characterize floods and reduce flood risk, flood simulation tools have been developed and widely applied. Hydrodynamic models for inundation simulation are generally sophisticated, yet they normally require massive setup and computational costs. In contrast, simplified conceptual models may be more easily applied and efficient. Based on the Hierarchical Filling-and-Spilling or Puddle-to-Puddle Dynamic Filling-and-Spilling Algorithms (i.e., HFSAs), Safer_RAIN has been developed as a fast-processing DEM-based model for modelling pluvial flooding over large areas. This study assesses Safer_RAIN applicability outside the context for which it was originally developed by looking at two different inundation problems with point-source flooding volumes: (1) rural inundation modelling associated with levee breaching/overtopping; (2) urban flooding caused by drainage systems outflow volumes.
... However, contemporary constructions on floodplains and farming on riverbeds during lean flow seasons have led to increased encroachments. The surge in construction on floodplains has modified runoff patterns into rivers, escalated pollution inflows with runoff, diminished groundwater recharge and base flows in rivers, and severed ecological linkages between rivers, floodplains, and floodplain wetlands (Serra-Llobet et al., 2022). Farming on riverbeds and the use of modern chemical pesticides like DDT and HCH have resulted in the contamination of the riverbed, causing harm to aquatic organisms, particularly hyporheic biota, and disrupting upper aquatic animal mating sites (Rad et al., 2022). ...
Ensuring the sustainable growth of the Ganga River is an imperative undertaking that addresses environmental, social, and economic obstacles. The Ganga holds immense cultural and economic significance in India, but it is plagued by several problems, including pollution, excessive water extraction, and habitat deterioration. The Indian Central Government intends to transition from the Namami Ganga Project to the Arth Ganga Project. This shift aims to promote the sustainable development of the Ganga River and its surrounding territories by emphasizing the economic and developmental activities associated with the river. The Arth Ganga Project aims to establish an economic connection between the people of the country and the Ganga River. This study aims to thoroughly examine the Arth Ganga Project, including its idea, distinctive characteristics, objectives, and implementation strategies for the rejuvenation of the Ganga River.
... Particularly, catastrophic floods are one of the most widespread and frequent natural disasters on Earth (Li et al., 2013(Li et al., , 2015Costabile et al., 2021;Li et al., 2022b;Mudashiru et al., 2021). In July 2021, several European countries experienced consecutive rainstorms and floods, devastatingly damaging many homes and businesses, causing almost 700 injuries, and 200 people died in the floods, where Germany and Belgium suffered the worst damage (Fekete and Sandholz, 2021;Bosseler et al., 2021;Serra-Llobet et al., 2022). In particular, more than 130 lives were lost in the Ahr Valley to the south of Bonn, Germany. ...
The advancing climate change increases the danger of heavy rainfall events and devastating floods, which significantly threaten people’s lives and properties. Geographic information system (GIS) has been a valuable tool for mapping flood risks and emergency management worldwide. In this paper, we develop an interactive evacuation tool to improve public flood perception. This work presents how to create an interactive and animated evacuation tool to strengthen the population’s preparedness and action ability in case of a flood. We simulate water depths and flow velocities for a flood scenario in Bonn, Germany. Afterwards, we investigate the flood’s impact on buildings and streets for different flood situations using geoinformation tools in the software QGIS. Based on thresholds from the literature, we identify endangered buildings where inhabitants have to evacuate and streets still ensuring safe locomotion options during the advancing flood. Taking possible shelter points for the population into account then allows for computing the shortest path to the nearest shelter at each flood situation. Our findings are summarized in evacuation maps that can be used together as interactive information tools for the public and can also serve rescue management and disaster education.
... Firstly, hydrogeomorphology allows a better preliminary understanding of a river system, its trajectory and its degradation Fryirs, 2015;Grabowski et al., 2014;. Secondly, that understanding guides an evaluation of the river's restoration potential, to frame which uses and human benefits are reasonable to expect in the system, and which are not (Auerbach et al., 2014;Gilvear et al., 2013;Serra-Llobet et al., 2022). Finally, it is crucial for monitoring the results and repercussions of a project . ...
Published paper: http://dx.doi.org/10.1002/rra.4304
Integrating hydrogeomorphological principles into the restoration of degraded rivers can achieve sustainable results for a variety of objectives and human benefits that are consistent with the potential functioning of rivers as well as their uses. Despite recent management approaches inspired by these principles, several restoration projects largely involve controlling river processes and target specific one-dimensional objectives often associated with the habitat of a few high-valued fish species or with rivers steadiness and aesthetics. Although there is overall a lack of post-project monitoring, several projects appear to have failed or had mixed success. This research aims to answer the question: What are the real drivers behind river restoration projects? Four restoration projects in Quebec (Canada) were characterized through a qualitative research process of support and interviews with the organizations running them as well as with two representatives of ministries involved in river restoration and management. The results identify two major drivers for the formulation of restoration objectives: project funding and stakeholder expertise. We propose a new analytical framework including these drivers, which appear to act as both conditions and motivations guiding the objectives of the projects and their diversity. Following diverse sociocultural and legislative contexts shaping these drivers, they may facilitate or restrict the integration of hydrogeomorphological principles towards diversified objectives and benefits. This supports regulation that is better informed by scientific knowledge about hydrogeomorphological and sociocultural river dynamics, knowledge sharing between academic researchers and environmental organizations, and collaboration between stakeholders and communities living around rivers.
... In the practice of CFR, strategic planning is required to increase spatiotemporal habitat heterogeneity while paying special attention to the quantity and arrangement of high-connectivity habitats in the initial stage of environmental transitions. It may be useful to also consider that floodplain restoration not only contributes to species conservation but can also provide societal long-term benefits such as flood risk reduction and recreation (Serra-Llobet et al. 2022). Ward JV, Tockner K, Arscott DB, Claret C (2002) ...
Progressive floodplain terrestrialization leads to the deterioration of floodplain ecosystems. Although the importance of hydrological connectivity between floodplain habitats and river channels for floodplain-dependent organisms has been emphasized, less attention has been paid to the temporal relationship between habitat degradation and aquatic organisms. In this study, we examined temporal changes in mussel population structures and the hydrological connectivity of pond-like floodplain water bodies (FWBs) in the terrestrialized floodplains of a lowland river in Japan. We tested the hypothesis that FWB habitats for mussels degrade over time, while newly formed FWBs contribute to providing recruitment sites for mussels. The habitat age for 53 FWBs was determined as of 2018, using historical aerial photographs. Inundation frequency, mussel abundance, and size structures (shell length) were also investigated in the FWBs in 2007 and 2018. Mussel abundance decreased with FWB aging (6–36 years), which coincided with a decrease in inundation frequency. In most existing FWBs, mussel abundance in all size classes decreased over the decade (2007–2018). In contrast, small individuals occurred in the newly formed FWBs at age 6, and in the existing FWBs where inundation frequency slightly increased over the decade (2007–2018), such FWBs were rare. In conclusion, the “young” and “rejuvenated” FWBs were found to be critically important for the recruitment and persistence of mussel populations. This suggests that the floodplain management strategy of “cyclic floodplain rejuvenation” could be applicable for mussel conservation in terrestrialized floodplains of lowland rivers.
