Showing papers in "Wiley Interdisciplinary Reviews: Water in 2021"

Beaver: Nature's ecosystem engineers

Abstract: Beavers have the ability to modify ecosystems profoundly to meet their ecological needs, with significant associated hydrological, geomorphological, ecological, and societal impacts. To bring together understanding of the role that beavers may play in the management of water resources, freshwater, and terrestrial ecosystems, this article reviews the state-of-the-art scientific understanding of the beaver as the quintessential ecosystem engineer. This review has a European focus but examines key research considering both Castor fiber-the Eurasian beaver and Castor canadensis-its North American counterpart. In recent decades species reintroductions across Europe, concurrent with natural expansion of refugia populations has led to the return of C. fiber to much of its European range with recent reviews estimating that the C. fiber population in Europe numbers over 1.5 million individuals. As such, there is an increasing need for understanding of the impacts of beaver in intensively populated and managed, contemporary European landscapes. This review summarizes how beaver impact: (a) ecosystem structure and geomorphology, (b) hydrology and water resources, (c) water quality, (d) freshwater ecology, and (e) humans and society. It concludes by examining future considerations that may need to be resolved as beavers further expand in the northern hemisphere with an emphasis upon the ecosystem services that they can provide and the associated management that will be necessary to maximize the benefits and minimize conflicts. This article is categorized under:Water and Life > Nature of Freshwater Ecosystems.

Toward catchment hydro-biogeochemical theories

Abstract: Headwater catchments are the fundamental units that connect the land to the ocean. Hydrological flow and biogeochemical processes are intricately coupled, yet their respective sciences have progressed without much integration. Reaction kinetic theories that prescribe rate dependence on environmental variables (e.g., temperature and water content) have advanced substantially, mostly in well-mixed reactors, columns, and warming experiments without considering the characteristics of hydrological flow at the catchment scale. These theories have shown significant divergence from observations in natural systems. On the other hand, hydrological theories, including transit time theory, have progressed substantially yet have not been incorporated into understanding reactions at the catchment scale. Here we advocate for the development of integrated hydro-biogeochemical theories across gradients of climate, vegetation, and geology conditions. The lack of such theories presents barriers for understanding mechanisms and forecasting the future of the Critical Zone under human- and climate-induced perturbations. Although integration has started and co-located measurements are well under way, tremendous challenges remain. In particular, even in this era of "big data," we are still limited by data and will need to (1) intensify measurements beyond river channels and characterize the vertical connectivity and broadly the shallow and deep subsurface; (2) expand to older water dating beyond the time scales reflected in stable water isotopes; (3) combine the use of reactive solutes, nonreactive tracers, and isotopes; and (4) augment measurements in environments that are undergoing rapid changes. To develop integrated theories, it is essential to (1) engage models at all stages to develop model-informed data collection strategies and to maximize data usage; (2) adopt a "simple but not simplistic," or fit-for-purpose approach to include essential processes in process-based models; (3) blend the use of process-based and data-driven models in the framework of "theory-guided data science." Within the framework of hypothesis testing, model-data fusion can advance integrated theories that mechanistically link catchments' internal structures and external drivers to their functioning. It can not only advance the field of hydro-biogeochemistry, but also enable hind- and fore-casting and serve the society at large. Broadly, future education will need to cultivate thinkers at the intersections of traditional disciplines with hollistic approaches for understanding interacting processes in complex earth systems.This article is categorized under:Science of Water > Methods

The benefits and negative impacts of citizen science applications to water as experienced by participants and communities

Abstract: Funding information Japan Society for the Promotion of Science (JSPS), Grant/Award Number: 19018 Abstract Citizen science is proliferating in the water sciences with increasing public involvement in monitoring water resources, climate variables, water quality, and in mapping and modeling exercises. In addition to the well-reported scientific benefits of such projects, in particular solving data scarcity issues, it is common to extol the benefits for participants, for example, increased knowledge and empowerment. We reviewed 549 publications concerning citizen science applications in the water sciences to examine personal benefits and motivations, and wider community benefits. The potential benefits of involvement were often simply listed without explanation or investigation. Studies that investigated whether or not participants and communities actually benefitted from involvement, or experienced negative impacts, were uncommon, especially in the Global South. Assuming certain benefits will be experienced can be fallacious as in some cases the intended benefits were either not achieved or in fact had negative impacts. Identified benefits are described and we reveal that more consideration should be given to how these benefits interrelate and how they build community capitals to foster their realization in citizen science water projects. Additionally, we describe identified negative impacts showing they were seldom considered though they may not be uncommon and should be borne in mind when implementing citizen science. Given the time and effort commitment made by citizen scientists for the benefit of research, there is a need for further study of participants and communities involved in citizen science applications to water, particularly in low-income regions, to ensure both researchers and communities are benefitting.

Arctic wetland system dynamics under climate warming

Abstract: Warming and hydrological changes have already affected and shifted environments in the Arctic. Arctic wetlands are complex systems of coupled hydrological, ecological, and permafrost-related processes, vulnerable to such environmental changes. This review uses a systems perspective approach to synthesize and elucidate the various interlinked responses and feedbacks of Arctic wetlands to hydroclimatic changes. Starting from increased air temperatures, subsequent permafrost thaw and concurrent hydrological changes are identified as key factors for both shrinkage and expansion of wetland area. Other diverse factors further interact with warming, hydrological changes, and permafrost thaw in altering the Arctic wetland systems. Surface albedo shifts driven by land cover alterations are powerful in reinforcing Arctic warming, while vegetation-related factors can balance and decelerate permafrost thaw, causing negative feedback loops. With the vast amounts of carbon stored in Arctic wetlands, their changes in turn affect the global carbon cycle. Overall, the systems perspectives outlined and highlighted in this review can be useful in structuring and elucidating the interactions of wetlands with climate, hydrological, and other environmental changes in the Arctic, including the essential permafrost-carbon feedback. This article is categorized under: Conservation, Management, and Awareness.

Applications of Google Earth Engine in fluvial geomorphology for detecting river channel change

Abstract: Cloud‐based computing, access to big geospatial data, and virtualization, whereby users are freed from computational hardware and data management logistics, could revolutionize remote sensing applications in fluvial geomorphology. Analysis of multitemporal, multispectral satellite imagery has provided fundamental geomorphic insight into the planimetric form and dynamics of large river systems, but information derived from these applications has largely been used to test existing concepts in fluvial geomorphology, rather than for generating new concepts or theories. Traditional approaches (i.e., desktop computing) have restricted the spatial scales and temporal resolutions of planimetric river channel change analyses. Google Earth Engine (GEE), a cloud‐based computing platform for planetary‐scale geospatial analyses, offers the opportunity to relieve these spatiotemporal restrictions. We summarize the big geospatial data flows available to fluvial geomorphologists within the GEE data catalog, focus on approaches to look beyond mapping wet channel extents and instead map the wider riverscape (i.e., water, sediment, vegetation) and its dynamics, and explore the unprecedented spatiotemporal scales over which GEE analyses can be applied. We share a demonstration workflow to extract active river channel masks from a section of the Cagayan River (Luzon, Philippines) then quantify centerline migration rates from multitemporal data. By enabling fluvial geomorphologists to take their algorithms to petabytes worth of data, GEE is transformative in enabling deterministic science at scales defined by the user and determined by the phenomena of interest. Equally as important, GEE offers a mechanism for promoting a cultural shift toward open science, through the democratization of access and sharing of reproducible code.

Floods and the COVID-19 pandemic—A new double hazard problem

Abstract: The coincidence of floods and coronavirus disease 2019 (COVID-19) is a genuine multihazard problem. Since the beginning of 2020, many regions around the World have been experiencing this double hazard of serious flooding and the pandemic. There have been 70 countries with flood events occurring after detection of the country's first COVID-19 case and hundreds of thousands of people have been evacuated. The main objective of this article is to assess challenges that arise from complex intersections between the threat multipliers and to provide guidance on how to address them effectively. We consider the limitations of our knowledge including "unknown unknowns." During emergency evacuation, practicing social distancing can be very difficult. However, people are going to take action to respond to rising waters, even if it means breaking quarantine. This is an emergency manager's nightmare scenario: two potentially serious emergencies happening at once. During this unprecedented year (2020), we are experiencing one of the most challenging flood seasons we have seen in a while. Practical examples of issues and guides for managing floods and COVID-19 are presented. We feel that a new approach is needed in dealing with multiple hazards. Our main messages are: a resilience approach is needed whether in response to floods or a pandemic; preparation is vital, in addition to defense; the responsible actors must be prepared with actions plans and command structure, while the general population must be involved in the discussions so that they are aware of the risk and the reasons for the actions they must take. This article is categorized under:Engineering Water > Methods.

Managing floodplains using nature-based solutions to support multiple ecosystem functions and services

Abstract: Global Change Research Institute CAS, Brno, Czech Republic Jan Evangelista Purkyně University in Ústí nad Labem, Ústí nad Labem, Czech Republic Department of Economics and Law, University of Macerata, Marche, Italy University of Ljubljana, Faculty of Civil and Geodetic Engineering, Ljubljana, Slovenia Department of Environment, Land and Infrastructure Engineering (DIATI), Politecnico di Torino, Torino, Italy Faculty of Humanities, Charles University, Praha, Czech Republic National Forest Center, Banska Bystrica, Slovakia Faculty of Ecology and Environmental Sciences, Technical University in Zvolen, Zvolen, Slovakia

Operational and emerging capabilities for surface water flood forecasting

Abstract: Surface water (or pluvial) flooding is caused by intense rainfall before it enters rivers or drainage systems. As the climate changes and urban populations grow, the number of people around the world at risk of surface water flooding is increasing. Although it may not be possible to prevent such flooding, reliable and timely flood forecasts can help improve preparedness and recovery. Unlike riverine and coastal flooding where forecasting methods are well established, surface water flood forecasting presents a unique challenge due to the high uncertainties around predicting the location, timing and impact of what are typically localised events. Over the past five years, there has been rapid development of convection-permitting numerical weather prediction models, ensemble forecasting and computational ability. It is now theoretically feasible to develop operational surface water forecasting systems. This paper identifies three approaches to surface water forecasting utilising state of the art meteorological forecasts; empirical based scenarios, hydrological forecasts linked to pre-simulated impact scenarios, and, real-time hydrodynamic simulation. Reviewing operational examples of each approach provides an opportunity to learn from international best practice to develop targeted, impact-based, surface water forecasts to support informed decision-making. Although the emergence of new meteorological and hydrological forecasting capabilities is promising, there remains a scientific limit to the predictability of convective rainfall. To overcome this challenge, we suggest that a re-thinking of the established role of flood forecasting is needed, alongside the development of interdisciplinary solutions for communicating uncertainty and making the best use of all available data to increase preparedness.

Revisiting global trends in freshwater insect biodiversity

Abstract: A recent global meta‐analysis reported a decrease in terrestrial but increase in freshwater insect abundance and biomass (van Klink et al., Science 368, p. 417). The authors suggested that water quality has been improving, thereby challenging recent reports documenting drastic global declines in freshwater biodiversity. We raise two major concerns with the meta‐analysis and suggest that these account for the discrepancy with the declines reported elsewhere. First, total abundance and biomass alone are poor indicators of the status of freshwater insect assemblages, and the observed differences may well have been driven by the replacement of sensitive species with tolerant ones. Second, many of the datasets poorly represent global trends and reflect responses to local conditions or nonrandom site selection. We conclude that the results of the meta‐analysis should not be considered indicative of an overall improvement in the condition of freshwater ecosystems.

On doing hydrology with dragons: Realizing the value of perceptual models and knowledge accumulation

Abstract: Department of Civil Engineering, University of Bristol, Bristol, UK Cabot Institute for the Environment, University of Bristol, Bristol, UK Institute for Environmental Science and Geography, University of Potsdam, Potsdam, Germany Department of Civil Engineering, University of Victoria, Victoria, British Columbia, Canada School of Earth and Ocean Sciences, University of Victoria, Victoria, British Columbia, Canada School of Geographical Sciences, University of Bristol, Bristol, UK Institute of Earth and Environmental Sciences, University of Freiburg, Freiburg, Germany

Intermittent rivers and ephemeral streams: Perspectives for critical zone science and research on socio-ecosystems

Abstract: Intermittent rivers and ephemeral streams (IRES) are now recognized to support specific freshwater biodiversity and ecosystem services and represent approximately half of the global river network, a fraction that is likely to increase in the context of global changes. Despite large research efforts on IRES during the past few decades, there is a need for developing a systemic approach to IRES that considers their hydrological, hydrogeological, hydraulic, ecological, and biogeochemical properties and processes, as well as their interactions with human societies. Thus, we assert that the interdisciplinary approach to ecosystem research promoted by critical zone sciences and socio‐ecology is relevant. These approaches rely on infrastructure—Critical Zone Observatories (CZO) and Long‐Term Socio‐Ecological Research (LTSER) platforms—that are representative of the diversity of IRES (e.g., among climates or types of geology. We illustrate this within the French CZO and LTSER, including their diversity as socio‐ecosystems, and detail human interactions with IRES. These networks are also specialized in the long‐term observations required to detect and measure ecosystem responses of IRES to climate and human forcings despite the delay and buffering effects within ecosystems. The CZO and LTSER platforms also support development of innovative techniques and data analysis methods that can improve characterization of IRES, in particular for monitoring flow regimes, groundwater‐surface water flow, or water biogeochemistry during rewetting. We provide scientific and methodological perspectives for which this interdisciplinary approach and its associated infrastructure would provide relevant and original insights that would help fill knowledge gaps about IRES.

Resocializing digital water transformations: Outlining social science perspectives on the digital water journey

Abstract: Funding information: National Cyber Security Centre; Scottish Government, Grant/Award Number: Hydro Nation Scholars; University of Manchester, Grant/Award Number: Presidential fellowship; University of Manchester, Grant/Award Number: SEED PGR scholarship (Amankwaa).

Baseflow and transmission loss: A review

Abstract: There is an extensive literature dealing with the interaction between groundwater and surface water, and this includes major reviews on baseflow, transmission losses, baseflow recession analysis, and broader aspects of low flows. Although these are mature topics in hydrology, they continue to attract strong interest, with hundreds of papers published in leading journals over the past 20 years. Our comprehensive review of the relevant literature focusses in detail on the use of linear and nonlinear models of recession discharge, and on transmission loss. From this review we identify three approaches to understanding recession, namely (a) theoretical approaches based on the Boussinesq equation, (b) applications of recession slope analysis, and (c) estimates of transmission loss by input–output water balance. We review the application of these techniques to ephemeral and humid areas and note the wide adoption of linear models despite most researchers accepting that the processes are nonlinear. Few papers address the characteristics of groundwater flow to ephemeral streams from unconfined aquifers. Although initially considered an ephemeral arid/semi-arid stream feature, transmission loss occurs in streams in humid areas. Interestingly, we identify a significant omission in the literature, in that while it is common to observe nonlinear behavior in streamflow recessions, little explicit account has been given to the role of transmission loss which can be an important factor in identifying the structure of nonlinear recession models. This article is categorized under: Science of Water > Hydrological Processes.

Advancing hydrological process understanding from long-term resistivity monitoring systems

Abstract: Monitoring subsurface flow and transport processes over a wide range of spatiotemporal scales remains one of the greatest challenges in hydrology. Electrical geophysical techniques have been implemented to non-invasively investigate a broad range of subsurface hydrological processes. Recent advances in instrumentation and interpretational tools highlight the emerging opportunities to adopt long term resistivity monitoring (LTRM) to improve understanding of flow and transport processes operating over monthly to decadal timescales that are not adequately captured in short-term monitoring datasets and are temporally aliased in datasets constructed from occasional reoccupation of a study site. The emergence of LTRM as a robust tool in hydrology represents a paradigm shift in geophysical data acquisition and analysis, with resistivity monitoring now evolving into a hydrological decision support technology. We describe the theoretical basis for adopting LTRM for non-invasive monitoring of hydrological state variables over multiple spatial scales and with higher temporal resolution than achieved from periodic reoccupation of a field site. Instrumentation developments facilitating autonomous data acquisition at off the grid field sites are discussed, along with advances in data processing that enhance the hydrological information content inherent in LTRM datasets. Case studies from a diverse range of hydrology subdisciplines highlight the largely untapped potential for LTRM to provide information beyond the reach of established hydrology tools. Future opportunities and challenges relating to the more widespread adoption of LTRM, including addressing inherent uncertainty in resistivity interpretation, upscaling, computational and modelling needs are critically discussed.

It's the product not the polymer: Rethinking plastic pollution

Abstract: Mismanaged plastic waste poses a complex threat to the environments that it contaminates, generating considerable concern from academia, industry, politicians, and the general public. This concern has driven global action that presents a unique opportunity for widespread environmental engagement beyond the immediate problem of the persistence of plastic in the environment. But for such an opportunity to be realized, it is vital that the realities of plastic waste are not misrepresented or exaggerated. Hotspots of plastic pollution, which are often international in their source, present complex environmental problems in certain parts of the world. Here we argue, however, that the current discourse on plastic waste overshadows greater threats to the environment and society at a global scale. Antiplastic sentiments have been exploited by politicians and industry, where reducing consumers' plastic footprints are often confused by the seldom-challenged veil of environmental consumerism, or “greenwashing.” Plastic is integral to much of modern day life, and regularly represents the greener facilitator of society's consumption. We conclude that it is the product, not the polymer that is driving the issue of plastic waste. Contemporary consumption and disposal practices are the root of much of the anthropogenic waste in the environment, plastic, or not. Effective environmental action to minimize plastic in the environment should be motivated by changes in consumption practices, policies, and product design, and should be informed by objective science and legislation. This article is categorized under:. Science of Water > Hydrological Processes. © 2020 The Authors. WIREs Water published by Wiley Periodicals LLC.

Green infrastructure: the future of urban flood risk management?

Abstract: Urban flooding is a key global challenge which is expected to become exacerbated under global change due to more intense rainfall and flashier runoff regimes over increasingly urban landscapes. Consequently, many cities are rethinking their approach to flood risk management by using Green Infrastructure (GI) solutions to reverse the legacy of hard engineering flood management approaches. The aim of GI is to attenuate, restore and recreate a more natural flood response, bringing hydrological responses closer to pre-urbanised conditions. However, GI effectiveness is often difficult to determine, and depends on both the magnitude of storm events and the spatial scale of GI infrastructure. Monitoring of the successes and failures of GI schemes is not routinely conducted. Thus, it can be difficult to determine whether GI provides a sustainable solution to manage urban flooding. This paper provides an international perspective on the current use of GI for urban flood mitigation and the solutions it offers in light of current and future challenges. An increasing body of literature further suggests that GI can be optimised alongside grey infrastructure to provide a holistic solution that delivers multiple co-benefits to the environment and society, while increasing flood resilience. GI will have to work synergistically with existing and upgraded grey infrastructure if urban flood risk is to be managed in a futureproof manner. Here, we discuss a series of priorities and challenges that must be overcome to enable integration of GI into existing stormwater management frameworks that effectively manage flood risk.

Perceptual perplexity and parameter parsimony

Abstract: This article reconsiders the concept of a perceptual model of hydrological processes as the first stage to be considered in developing a procedural model for a particular catchment area. While various perceptual models for experimental catchments have been developed, the concept is not widely used in defining or evaluating catchment models. This is, at least in part, because of the evident complexity possible in a perceptual model and the approximate nature of procedural model structures and parameterizations, particularly where there is a requirement for parameter parsimony. A perceptual model for catchments in Cumbria, North-West England, is developed as an exemplar and illustrated in terms of time varying distribution functions. Two critical questions are addressed: how can perceptual model hypotheses be tested at scales of interest, and how can constraints then be imposed on the basis of qualitative perceptual knowledge in conditioning predictive models? It is suggested that there is value in perceptual information, particularly in thinking about predicting the impacts of future change and that we still have much to learn about moving from observational and perceptual complexity to parsimonious predictability. This article is categorized under: Science of Water. © 2021 The Authors. WIREs Water published by Wiley Periodicals LLC.

LéXPLORE: A floating laboratory on Lake Geneva offering unique lake research opportunities

Abstract: Limnology Center, ENAC-EPFL, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Surface Waters Research and Management, Kastanienbaum, Switzerland Université Savoie Mont Blanc, INRAE, CARRTEL, Thonon-les-Bains, France Department F.-A. Forel for Environmental and Aquatic Sciences, University of Geneva, Geneva, Switzerland Institute of Earth Surface Dynamics, Faculty of Geosciences and Environment, University of Lausanne, Lausanne, Switzerland