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In coastal regions, compound flooding, driven by multiple flood hazard sources, can cause greater damage than when the flood drivers occur in isolation. This study focuses on compound flooding from extreme precipitation and storm surge in China's Qiantang Estuary. We quantify the potential of compound flooding by measuring bivariate joint statistical dependence and joint return period (JRP). We find a significant positive dependence between the two flood drivers considered, as indicated by Kendall's rank correlation coefficients. Compound events occur frequently, with an average of 2.65 events per year from 1979 to 2018, highlighting the significant concern of compound flooding for this estuary. Using a copula model, we demonstrate that considering the dependence between the two flood drivers shortens the JRP of compound flooding compared to the JRP assuming total independence. For a 1-in-10-yr precipitation event and 1-in-10-yr storm surge event, the JRP is 1 in 100 years when assuming total independence. However, it decreases to 1 in 32.44 years when considering their dependence. Ignoring the dependence between flood drivers can lead to an increase in the JRP of compound events, resulting in an underestimation of the overall flood risk. Our analysis reveals a strong link between the weather patterns creating compound events and extreme storm surge only events with tropical cyclone activity. Additionally, the extreme precipitation only events were found to be connected with the frontal system of the East Asian summer monsoon. This study highlights the importance of considering the dependence between multiple flood drivers associated with certain types of the same weather systems when assessing the flood risk in coastal regions. [ABSTRACT FROM AUTHOR]

Microbial pollution of recreational waters leads to millions of skin, respiratory, and gastrointestinal illnesses globally. Fecal indicator bacteria (FIB) are monitored to assess recreational waters but may not reflect the presence of Staphylococcus aureus, a global leader in bacterial fatalities. Since many community‐acquired S. aureus skin infections are associated with high recreational water usage, this study measured and modeled S. aureus, methicillin‐resistant S. aureus (MRSA), and FIB (Enterococcus spp., Clostridium perfringens) concentrations in seawater and sand at six beaches in Hilo, Hawai'i, USA, over 37 sample dates from July 2016 to February 2019 using culturing techniques. Generalized linear models predicted bacterial concentrations with physicochemical and environmental data. Beach visitors were also surveyed on their preferred activities. S. aureus and FIB concentrations were roughly 6–78 times higher at beaches with freshwater discharge than at those without. Seawater concentrations of Enterococcus spp. were positively associated with MRSA but not S. aureus. Elevated S. aureus was associated with lower tidal heights, higher freshwater discharge, onsite sewage disposal system density, and turbidity. Regular monitoring of beaches with freshwater input, utilizing real‐time water quality measurements with robust modeling techniques, and raising awareness among recreational water users may mitigate exposure to S. aureus, MRSA, and FIB. Practitioner Points: Staphylococcus aureus and fecal bacteria concentrations were higher in seawater and sand at beaches with freshwater discharge.In seawater, Enterococcus spp. positively correlated with MRSA, but not S. aureus.Freshwater discharge, OSDS density, water turbidity, and tides significantly predicted bacterial concentrations in seawater and sand.Predictive bacterial models based upon physicochemical and environmental data developed in this study are readily available for user‐friendly application. [ABSTRACT FROM AUTHOR]

To address ongoing threats from human pressures and climate changes, water managers and users require a visual tool that provides accurate information about the health of waterbodies for decision making. However, there is a lack of less sophisticated methods, such as biotic scoring, to assess the health of rivers in West Africa. To bridge this gap, we have developed a macroinvertebrate-based scoring system for monitoring the health of rivers in the Sahelian regions. We adopted a multi-habitat sampling approach to collect macroinvertebrates using hand nets, and these specimens were identified mostly to family taxonomic level using keys. We recorded more than 75 taxa of macroinvertebrates, each assigned relative sensitivity scores to human disturbances ranging from 1 (very tolerant) to 10 (highly sensitive). The Burkina Biotic Score System (BBIOSS) and the Average Score Per Taxa (ASPT) demonstrated a strong and significant correlation with environmental variables, including anthropogenic pressures types (r = 0.6; p < 0.01) making it a robust tool for monitoring rivers. Here, our findings revealed that all taxa scored are expected to be those reported in Western African freshwater. This study has produced an effective tool that can be used or adapted to monitor other riverine ecosystems in West Africa, potentially contributing to the preservation of water and biological resources. [ABSTRACT FROM AUTHOR]

When the Ebola virus crossed undetected into Sierra Leone and exacerbated the 2014-15 crisis, the World Health Organization blamed the breach on a traditional healer treating patients from Guinea. Meanwhile, local residents initially maintained that her death was not Ebola-related but a serpent's curse, an assumption grounded in lived experience of snake charmer spectacles. Both narratives drowned out evidence that the virus spread not via the healer's covert herbalism, but via her professional connections at the local government clinic and, more broadly, an overtaxed and undertrained public health system. This article takes local rumours around Ebola as vernacular epidemiologies that resonated with sensory experience. They show that both community and humanitarian actors had information; complications arose from the diverse experiences and expectations that shaped responses to that information. Such expectations emerge from the borderland geography, where colonial infrastructures continue to channel perception according to "upriver", "downriver", and "crossriver" phenomenologies. [ABSTRACT FROM AUTHOR]

Plastic pollution is now recognised as a growing concern for both the environment and associated biota. Consequently, a plethora of scientific reports are being produced regarding the occurrence, distribution, and transfer pathways of litter particles. However, there are scientific gaps that need to be filled regarding micro- and nanoplastic impacts on marine and freshwater organisms. This Special Issue (SI) aimed to provide an update on plastic pollution and its consequences on aquatic ecosystems, with a particular focus on biological domains, by adopting a multidisciplinary perspective. Several research articles and reviews were collected, focusing on the origin, fate, and effects of plastics in marine and freshwater environments, along with their interactions with biotic components. We believe this SI will contribute to the development of new studies on plastic pollution and the elaboration of science-based policies at different levels of our modern society. [ABSTRACT FROM AUTHOR]

This article discusses the governance aspects of managing river, lake, and aquifer basins, both at the transboundary and domestic levels. It highlights the importance of basin organizations in facilitating negotiation, data sharing, and decision-making among stakeholders. The article also explores the challenges faced by international basin organizations, such as power asymmetries and the inclusion of non-state actors. Additionally, it examines the scale implications of transboundary agreements and the participation of civil society in water management. The article concludes by emphasizing the need for improved institutions and cooperation in order to effectively manage water resources. [Extracted from the article]

Salinization is a global threat to freshwater habitats that has been intensified by climate change. Monitoring, assessment and management of salinity is therefore essential. The first step is to set criteria that are sufficiently stringent to protect ecosystem health. However, many countries have not yet defined criteria, and there are substantial differences between criteria. This has been noted in the EU, where salinity is a required “supporting element” for ecological status in inland waters but also for implementation of UN Sustainable Development Goal (SDG) indicator 6.3.2. for “good ambient water quality” where different approaches and widely different threshold values were reported for salinity criteria. Much of this information has not been published and is difficult to access, hindering further efforts to address the problem. We first discuss the implications of salinization for freshwater ecological health. We go on to discuss the principles and guidelines on how salinity criteria to protect ecology should be established. Next, we review salinity criteria submitted as part of implementation of SDG indicator 6.3.2 and the EU Water Framework Directive. Finally, we discuss setting salinity thresholds in an already-warming world and the challenges facing anyone trying to develop salinity criteria to protect freshwater ecosystems. This article is categorized under: Water and Life > Stresses and Pressures on Ecosystems Water and Life > Conservation, Management, and Awareness Science of Water > Water Quality [ABSTRACT FROM AUTHOR]

Environmental influences on species' functional traits are important ecological issues to assess biodiversity. Relationships among fish abundance, their functional traits, and environmental conditions across different levels of anthropogenic impacts in a tropical Brazilian river were evaluated. We combined RLQ and fourth-corner methods, utilizing local environmental variables and the Human Footprint Index (HFI) as a human activities indicator. Three HFI levels (High, Intermediate, and Low) and short-term (1993–2009) impact changes at each location were assigned. Fish with internal fertilization and small body sizes were strongly associated with high HFI scores. Grass-dominated riparian areas were common in altered locations, whereas less altered localities exhibited the riparian cover dominated by trees. Highly altered areas showed high HFI, grass-covered riparian zones, and small-sized species with internal fertilization (e.g., Cyprinodontiformes like Poecilia vivipara, Poecilia reticulata, and Phalloceros caudimaculatus). In contrast, less altered areas had tree-lined riparian zones and medium to large-sized species with external fertilization and diverse traits. Underlying deterministic processes shape species distribution, tied to environment and traits. Filtering of traits in the most altered locations may favor small-sized species with internal fertilization. This approach, utilizing HFI and local variables to assess trait–environment relationships of riverine fish, facilitates understanding organisms' responses to environmental constraints. [ABSTRACT FROM AUTHOR]

Incorporating societal considerations into decisions related to invasive species management is desirable, but can be challenging because it requires a solid understanding of the ecological functions and socio- cultural and economic benefits and values of the invaded environment before and after invasion. The ecosystem service (ES) concept was designed to facilitate such decision-making by establishing direct connections between ecosystem properties and human well-being, but its application in invasive species management has not been systematic. In this Discussion paper, we propose the adoption of the ES cascade model as a framework for understanding the environmental effects, costs and benefits associated with controlling an invasive shrub (Tamarix spp.) in riparian systems of the western United States. The cascade model has the advantage of explicitly dissecting social-ecological systems into five components: ecosystem structure and processes, ecological functions, ecosystem services, benefits and the economic and socio-cultural valuation of these services and benefits. The first two have received significant attention in the evaluation of Tamarix control effectiveness. The last three have long been implicitly acknowledged over decades of Tamarix management in the region, but have not been formally accounted for, which we believe would increase the effectiveness, accountability and transparency of management efforts. [ABSTRACT FROM AUTHOR]

The loose‐equilibrium concept (LEC) predicts that ecological assemblages change transiently but return towards an earlier or average structure. The LEC framework can help determine whether assemblages vary within expected ranges or are permanently altered following environmental change.Long‐lived, slow‐growing animals typically respond slowly to environmental change, and their assemblage dynamics may respond over decades, which transcends most ecological studies. Unionid mussels are valuable for studying dynamics of long‐lived animals because they can live >50 years and occur in dense, species‐rich assemblages (mussel beds). Mussel beds can persist for decades, but disturbance can affect species differently, resulting in variable trajectories according to differences in species composition within and among rivers.We used long‐term data sets (10–40 years) from seven rivers in the eastern United States to evaluate the magnitude, pace and directionality of mussel assemblage change within the context of the LEC.Site trajectories varied within and among streams and showed patterns consistent with either the LEC or directional change. In streams that conformed to the LEC, rank abundance of dominant species remained stable over time, but directional change in other streams was driven by changes in the rank abundance and composition of dominant species.Characteristics of mussel assemblage change varied widely, ranging from those conforming to the LEC to those showing strong directional change. Conservation approaches that attempt to maintain or create a desired assemblage condition should acknowledge this wide range of possible assemblage trajectories and that the environmental factors that influence those changes remain poorly understood. [ABSTRACT FROM AUTHOR]

The elevations of water surfaces hold important information on the earth's oceans and land surface waters. Ocean sea surface height is related to the internal change of the ocean's density and mass associated with ocean circulation and its response to climate change. The flow rates of rivers and volume changes of lakes are crucial to freshwater supplies and the hazards of floods and drought resulting from extreme weather and climate events. The Surface Water and Ocean Topography (SWOT) Mission is a new satellite using advanced radar technology to make headway in observing the variability of the elevation of water surfaces globally, providing fundamentally new information previously not available to the study of earth's waters. Here, we provide the first results of SWOT over oceans, rivers, and lakes. We demonstrate the potential of the mission to address science questions in oceanography and hydrology. Plain Language Summary: Earth is a water planet. The vast amount of ocean water has stored most of the heat released to the atmosphere since the Industrial Revolution through burning fossil fuels. Climate change is thus moderated by the ocean. Over land the freshwater in lakes, rivers, and reservoirs, a critical natural resource, is affected by the warming climate and direct human modifications. Processes of oceanic uptake of heat and carbon from the atmosphere and cycling of freshwater on land take place at spatial scales too small to have been adequately quantified from space. A new satellite, the Surface Water and Ocean Topography (SWOT) mission, was launched in December 2022. Using advanced radar technology, SWOT provides unprecedented global observations for understanding the ocean's role in climate change and how freshwater resources respond to human influence. SWOT observations near coasts will also advance understanding of how rising sea levels impact those coasts. Key Points: The first space observations of submesoscale ocean surface topography for understanding ocean's role in heat uptake from the atmosphereThe first space observations of the change of water storage of lakes and flow rates of rivers for understanding the freshwater cycleThe first space observations of the details of the change of coastal water levels to assess the impact of local sea level rise [ABSTRACT FROM AUTHOR]

Industrial and environmental granular flows commonly exhibit a phenomenon known as “granular segregation,” in which grains separate according to physical characteristics (size, shape, density), interfering with industrial applications (cement mixing, medicine, and food production) and fundamentally altering the behavior of geophysical flows (landslides, debris flows, pyroclastic flows, riverbeds). While size-induced segregation has been well studied, the role of grain shape has not. Here we conduct numerical experiments to investigate how grain shape affects granular segregation in dry and wet flows. To isolate the former, we compare dry, bidisperse mixtures of spheres alone with mixtures of spheres and cubes in a rotating drum. Results show that while segregation level generally increases with particle size ratio, the presence of cubes decreases segregation levels compared to cases with only spheres. Further, we find differences in the segregation level depending on which shape makes up each size class, reflecting differences in mobility when smaller grains are cubic or spherical. We find similar dynamics in simulations of a shear-driven coupled fluid-granular flow (e.g., a simulated riverbed), demonstrating that this phenomenon is not unique to rotating drums; however, in contrast to the dry system, we find that the segregation level increases in the presence of cubic grains, and fluid drag effects can qualitatively change segregation trends. Our findings demonstrate competing shape-induced segregation patterns in wet and dry flows that are independent from grain size controls, with implications for many industrial and geophysical processes. [ABSTRACT FROM AUTHOR]

The objective of this work is to contribute to the knowledge of the freshwater macroinvertebrate communities of Los Tuxtlas, Veracruz, Mexico. For this region, there is only limited knowledge of its aquatic crustaceans and mollusks. A total of 13,399 freshwater macroinvertebrates were collected from four river sections in each of the three sub-basins of the region using the Surber network in four seasons of an annual cycle (2021–2022) and were preserved in 70° alcohol. Organisms belonging to seven phyla, nine (sub)classes, 21 (sub)orders and 65 families were identified. The most abundant orders were Ephemeroptera (42.03%), with greatest abundance of the family Baetidae, and the orders Trichoptera (19.11%), Diptera (15.43%), and Coleoptera (3.98%). Four families exceeded 10% relative abundance, and together they total 61.02%: Baetidae (23.84%), Hydroptilidae (13.58%), Leptohyphidae (13.03%), Chironomidae (10.57%), and Elmidae (3.23%). The order Plecoptera was recorded for the first time in Los Tuxtlas, with three families. The orders Hydrachnidae and Ostracoda, as well as six families of the order Ephemeroptera, with only one previously recorded family, and six more families of the order Diptera, were also documented. Two species of invasive aquatic mollusks were found in several rivers and basins. In this work, a high diversity of freshwater macroinvertebrates occurred compared to other sites studied in Veracruz and Mexico, and new records of these taxa are provided for the region of Los Tuxtlas. [ABSTRACT FROM AUTHOR]

In times of rapid environmental changes, baseline biodiversity data are crucial for management. In freshwaters, fish inventories are commonly based on the capture and morphological identification of specimens. The sampling of environmental DNA (eDNA) provides an alternative to assess diversity across large catchments. Here, we used extensive historic data of fish communities collected across 89 river sites in all major catchments of Switzerland and compared their diversity and community composition to a single campaign of eDNA and electrofishing, respectively. Locally, we found that eDNA provided diversity estimates similar to the integrated historic richness, while the electrofishing campaign captured a significantly lower local richness. Fish species locally recorded by electrofishing were nested (Jaccard's dissimilarity index) within the respective eDNA community for most sites. Finally, eDNA sequence reads positively correlated with the overall electrofishing biomass. Despite the congruences, the eDNA data did not correlate well with the electrofishing water quality index. Overall, eDNA was more accurately assessing overall diversity than a simultaneous electrofishing campaign, but yet cannot be directly used to calculate fish-based water quality indices. [ABSTRACT FROM AUTHOR]

American Eel (Anguilla rostrata) population characteristics and distribution remain drastically understudied in the Caribbean region. We conducted the first island‐wide study to evaluate the distribution of density, length, and sex in relation to distance from the mouth of 23 stream reaches in five rivers in Puerto Rico. We found 287 American Eel at a mean density of 156.7 fish/ha. Sex ratios favored females (52:3) but most of the eel sampled were undifferentiated or undetermined. Generalized linear modeling indicated that upstream habitats with low eel density were optimal environments for production of large and female eel. Our findings indicate that Puerto Rico could significantly contribute to the spawning population and strengthen knowledge of American Eel in the Caribbean. Our findings could be used to guide local and range‐wide conservation efforts to ensure stream connectivity and access to optimal upstream habitat for survival of the population. [ABSTRACT FROM AUTHOR]

Despite the distance between their different communities and the difficulties of medieval travel, the Jews of northern Europe developed typical common legal and communal traditions. Rabbinic students traveled hundreds of kilometers to study with famous rabbis, rabbis themselves often relocated from one community to another, and questions were regularly sent to faraway rabbinic authorities and were quickly answered. This article sheds light on the movement and communication patterns of medieval Jewish scholars as a social group. It includes three sections; the first focuses on the movement patterns of prominent rabbis, the second on their forms of communication, and the third on the way these practices were reflected in the organization of larger communal structures. Overall, the article highlights the major role that networks of movement and communication played in the intellectual culture of the rabbinic elite (and other Jews as well) in high medieval northern Europe. [ABSTRACT FROM AUTHOR]

Biblical Hebrew has a rich vocabulary for clouds, rain, rivers, wadis, springs, wells, and cisterns, and this vocabulary indicates something of how ancient Israelites related to water. Water in all its forms was understood as a gift from God, especially when seasonal rain arrived according to expectation. Disruptions to the normal seasons were usually interpreted as a sign of judgment. By naming various forms of water and their divine origin, humans reveal their relationship with God and with water. [ABSTRACT FROM AUTHOR]

Although Pentecostalism is a major stream within Christianity in Sierra Leone, the first field where Protestant missionaries were active in tropical Africa, this ecclesial development remains marginally represented in research. The Pentecostalisation of Sierra Leone points to the nation's continuous recontextualization of Christianity from its inherited missionary vestiges to meet local cultural needs. In this paper, I discuss the retreat by Pentecostal clerics to nature (forests, rivers, and mountains) from where they expect to connect with the transcendent God and receive spiritual power. To do so, I first discuss Sierra Leone's traditional conceptualization of forests, rivers, and mountains as sites for the acquisition of spiritual power. Second, I briefly survey the emergence of Pentecostalism in Sierra Leone, probing the specific uses by Pentecostals of natural spaces. Finally, I conclude with an intercultural theological assessment of Sierra Leone's emerging Pentecostal uses and interpretations of natural spaces. [ABSTRACT FROM AUTHOR]

Rivers serve as vital water sources, maintain ecological equilibrium, and enhance landscapes. However, the looming issue of floating debris stemming from improper waste disposal and illegal discharge, poses an imminent threat to river ecosystems and their aesthetic appeal. Conventional human-led inspections prove labor-intensive, inefficient, and prone to errors. This study introduces an innovative approach for river debris detection, employing Unmanned Aerial Vehicles (UAVs) imagery in conjunction with a refined YOLOv5n model. This approach offers three key contributions. Primarily, the YOLOv5n model is bolstered by integrating the Efficient Channel Attention (ECA) module and reshaping the MobileNetV3 backbone to align with MobileNetV3S, thereby significantly streamlining computational demands and model intricacy. Additionally, precision and speed are augmented by eliminating the detection head for larger targets, while decreasing computational requirements. Subsequently, to counter dataset scarcity, we curate a UAV-derived river debris dataset, encompassing five prevalent debris types, serving as an indispensable resource for method refinement and assessment. Lastly, the upgraded model's evaluation on Jetson Nano yields an mAP of 87.2%, merely 0.7% lower than the original YOLOv5n model. Remarkably, the refined model achieves substantial reductions of 57.1% in parameters, 52.6% in volume, and 54.8% in GFLOPs. Additionally, inference time is abbreviated to 57.3ms per Jetson Nano image, 13.4ms faster than the original. These findings underscore edge computing's potential in river restoration. In conclusion, the fusion of deep learning object detection and UAV imagery empowers adept river debris detection. [ABSTRACT FROM AUTHOR]

Rivers frequently delimit the geographic ranges of species in the Amazon Basin. These rivers also define the boundaries between genetic clusters within many species, yet river boundaries have been documented to break down in headwater regions where rivers are narrower. To explore the evolutionary implications of headwater contact zones in Amazonia, we examined genetic variation in the Blue-capped Manakin (Lepidothrix coronata), a species previously shown to contain several genetically and phenotypically distinct populations across the western Amazon Basin. We collected restriction site-associated DNA sequence data (RADcap) for 706 individuals and found that spatial patterns of genetic structure indicate several rivers, particularly the Amazon and Ucayali, are dispersal barriers for L. coronata. We also found evidence that genetic connectivity is elevated across several headwater regions, highlighting the importance of headwater gene flow for models of Amazonian diversification. The headwater region of the Ucayali River provided a notable exception to findings of headwater gene flow by harboring non-admixed populations of L. coronata on opposite sides of a < 1-km-wide river channel with a known dynamic history, suggesting that additional prezygotic barriers may be limiting gene flow in this region. [ABSTRACT FROM AUTHOR]

The development of low‐oxygen zones threatening marine life (hypoxia) occurs annually in multiple coastal regions of the world. The largest estuary of the continental United States, the Chesapeake Bay, typically has ≈10 km3 of water with dioxygen concentrations <3 mg L−1 in July. As numerical methods for refining model resolutions in targeted areas are becoming common, there is interest in assessing the feasibility of simulating coastal hazards such as hypoxia in Earth System Models (ESMs). These coupled models are typically not constrained by observations and thus likely to feature systematic biases in their land, atmosphere, or ocean components. This study relies on four numerical experiments to evaluate the sensitivity of Chesapeake Bay hypoxia to changes or biases in its external physical forcings. Hypoxia exhibits only a minor decrease (−1.6%) after reducing the Bay's terrestrial freshwater discharge by 9.5% (but keeping terrestrial nutrient loadings the same). Changes in freshwater discharges have their largest impact on hypoxia during one extreme event (−37% during 2011 tropical storm Lee). Similarly, changing oceanic conditions on the shelf or their temporal frequency impact hypoxia by only 5%–6%, indicating that the latter is predominantly dictated by local conditions. Although these results are promising from the perspective of ESMs, additional components of ESMs will need to be evaluated before general conclusions can be reached. We notably speculate that the Bay's hypoxia would exhibit higher sensitivity to other forcings not examined here, notably air temperatures and nutrient loadings. Plain Language Summary: Many coastal embayments of the world experience the development of "dead zones" during the summer, defined by very low concentrations of oxygen in water. The dead zones negatively affect the ecosystem including commercially‐important fisheries. Such a dead zone can be found every summer in the Chesapeake Bay, the largest and most productive estuary in the continental United States. Although these phenomena are typically the focus of local or regional managers, recent improvements in computer capabilities raise the possibility that dead zones could be successfully represented in the same type of computer simulators used for century‐long projections of the Earth's climate. Such simulators would provide a long term projection for the severity of dead zones throughout the world. The present study examines whether a realistic representation of the Chesapeake Bay dead zone can be obtained using information from these global computer simulations. The results show that the representation of the dead zone is not substantially different when using the global data sets selected for this study. This positive outcome opens the door for additional tests that should focus on other components of the global simulators, notably air temperatures and nutrients inputs from the land to the coastal embayments. Key Points: Chesapeake Bay hypoxia shows only a weak sensitivity to continental shelf conditions and variabilityChanges in shelf hydrography propagate throughout the Bay but surface temperatures are set by the meteorological forcingShort term hydrological events are not always captured well by global land models which can impact hypoxia substantially [ABSTRACT FROM AUTHOR]

This paper explores the everyday experiences of crossing rivers that form local borders. It proposes and utilises the term ‘riverborderscape’ to bring together the particularities, complexities, and creativities associated with these border crossings. The term draws on three areas of scholarship. First, the riverborderscape draws on recent scholarly attention to the materiality, and effects on understanding space and place, of watery environments. Second, the term draws on scholarship from within border studies and cognate disciplines that highlights the border as a liminal space. Third, landscape geographies are used to examine the imagination and performance of crossing riverborderscapes. The paper reports on research carried out with passengers, crew, and communities on three rivers in South West England where the ferry routes cross local administrative boundaries. Over the course of the research, participants shared their experiences of crossing these river borders through writing and drawings created while on board the ferry, as well as through surveys and interviews. The research highlights the effects of the materiality of the river on the routes and experiences of crossing, the role of humour in the construction and subversion of everyday boundaries, and the river in‐between as a liminal space, a landscape where the imagination may be unmoored and creative licence temporarily set free. [ABSTRACT FROM AUTHOR]

Heatwaves are a global issue that threaten microbial populations and deteriorate ecosystems. However, how river microbial communities respond to heatwaves and whether and how high temperatures exceed microbial adaptation remain unclear. In this study, we proposed four types of pulse temperature‐induced microbial responses and predicted the possibility of microbial adaptation to high temperature in global rivers using ensemble machine learning models. Our findings suggest that microbial communities in parts of South American (e.g., Brazil and Chile) and Southeast Asian (e.g., Vietnam) countries are likely to change due to heatwave disturbance from 25 to 37°C for consecutive days. Furthermore, the microbial communities in approximately 48.4% of the global river gauge stations are prone to fast stress inadaptation, with approximately 76.9% of these stations expected to exceed microbial adaptation after heatwave disturbances. If emissions of particulate matter with sizes not more than 2.5 μm (PM2.5, an indicator of human activities) increase by twofold, the number of global rivers associated with the fast stress adaptation type will decrease by ~13.7% after heatwave disturbances. Understanding microbial responses is crucially important for effective ecosystem management, especially for fragile and sensitive rivers facing heatwave events. [ABSTRACT FROM AUTHOR]

Floods in ideal landscapes follow a coherent pattern where single water‐covered areas expand and afterward recede following the inverse sequence, but deviate in real landscapes due to natural or human factors resulting in water coverage shifts. Using remote sensing, we introduced two indices to describe the discrepancies between spatially integrated versus pixel‐level frequency distributions under maximum inundated conditions (dext) and throughout all flooding conditions (dtot), expressed as the relative weight of shifts on each landscape's maximum registered coverage, theoretically ranging between no displacement (<20%) to maximum displacement (≪inf). Globally, over 36 years inundations exhibited redistributions representing, on average, 25% and 45% of their peak extents revealing previously unnoticed extra engaged areas and rotational movements within events, rising up to 500% in meandering rivers (South America) and irrigated croplands (Central Asia). We also assessed the influence of natural and human variables and discussed the indices' potential for advancing flood research. Plain Language Summary: While in ideal landscapes surface water should display the same spatial distribution across the expansion and recession stages of any flooding event, real dynamics may drift away from this expected pattern. We developed two indices based on remote sensing data to locate where these shifts are important and understand how they are influenced by nature and humans. By analyzing data from around the world, we discovered that thanks to the displacement from the ideal distributions, surface water covered globally an extra quarter of the area. Natural factors like low terrain ruggedness and high aridity foster much larger inundation displacement. In regions hosting rivers that carry large quantities of sediment and often change their course (e.g., India and Perú), displacement engages five times more area in floods than expected. We also found that water infrastructure like reservoirs and irrigation also influenced inundation displacement. For instance, displacement was very relevant in intensely irrigated regions like Central Asia and Australia, reflecting surface water deviation as needed for crop production. Because these variations scope water's spatiotemporal dynamics with important implications for the provision of many ecosystem services, their quantification and assessment allow us to monitor and understand our ongoing imprint on regional inundation dynamics. Key Points: We developed two complementary indices to describe water cover shifts between and within flooding eventsOver the last 36 years, shifts expanded the global flooded‐affected area by 25% with another 20% redistributing at intermediate stagesFlat topographies, arid climates, and irrigation favor this phenomenon while river dams and channels inhibit it over time [ABSTRACT FROM AUTHOR]

A total of 114 samples collected from hospital wastewaters and rivers in Addis Ababa, Ethiopia were tested for non-sorbitol fermenting bacteria and coliphages. Sorbitol MacConkey agar is mainly used in the detection of E. coli O157:H7. However, other emerging diarrhoeagenic enteropathogens such as Plesiomonas shigelloides, Edwardsiella tarda, Providencia alcalifaciens, Escherichia albertii, Escherichia vulneris and Escherichia fergusonii were detected in the samples using this medium. Information for most of the emerging enteropathogens is scarce in most countries including Ethiopia. A total of 20 different genera, 38 species of nonsorbitol fermenting bacteria were isolated. Escherichia coli O157 could not be detected from any of the samples. All these backgrounds may mask the detection of Escherichia coli O157. Even if sorbitol MacConkey agar has several background limitations, different emerging diarrhoeagenic non-sorbitol fermenting bacteria were detected in the majority of the rivers and hospitals' wastewaters samples. The correlation between coliphages and non-sorbitol fermenting bacteria were not significant. As several bacteria have been isolated on sorbitol MacConkey agar medium, it is essential that the most selective laboratory techniques will be desired for outbreak investigation of E. coli O157, but other non-sorbitol fermenting enteropathogens should also be detected using sorbitol MacConkey agar in low resources countries. [ABSTRACT FROM AUTHOR]

Analysis of available monitoring data sets on concentrations of accidentally derived dissolved radiocesium in water bodies is indicative of two major physicochemical mechanisms responsible for their seasonal variations in water bodies in the course of the year: temperature dependence of radiocesium desorption from suspended material and ion-exchange remobilization of radiocesium by ammonium cations formed during decomposition of organic matter in anoxic conditions. An equation describing seasonal variations in concentration of dissolved radiocesium in water bodies has been derived accounting for two factors: water temperature, and combined concentration of key competing cations. [ABSTRACT FROM AUTHOR]

Lateral carbon transport through the land-to-ocean-aquatic-continuum (LOAC) represents a key component of the global carbon cycle. This LOAC involves complex processes, many of which are prone to anthropogenic perturbation, yet the influence of natural and human-induced drivers remains poorly constrained. This study examines the radiocarbon (14C) signatures of particulate and dissolved organic carbon (POC, DOC) and dissolved inorganic carbon (DIC) transported by Swiss rivers to assess controls on sources and cycling of carbon within their watersheds. Twenty-one rivers were selected and sampled during high-flow conditions in summer 2021, a year of exceptionally high rainfall. Δ14C values of POC range from −446‰ to −158‰, while corresponding ranges of Δ14C values for DOC and DIC are −377‰ to −43‰ and −301‰ to −40‰, respectively, indicating the prevalence of pre-aged carbon. Region-specific agricultural practices seem to have an influential effect on all three carbon phases in rivers draining the Swiss Plateau. Based on Multivariate Regression Analysis, mean basin elevation correlated negatively with Δ14C values of all three carbon phases. These contrasts between alpine terrain and the lowlands reflect the importance of overriding ecoregional controls on riverine carbon dynamics within Switzerland, despite high spatial variability in catchment properties. This article is part of the Theo Murphy meeting issue 'Radiocarbon in the Anthropocene'. [ABSTRACT FROM AUTHOR]

Inland waters are significant, yet highly uncertain, natural sources of nitrous oxide (N2O). Many emission models assume that N2O is only emitted from freshwaters, and that N2O sink behavior is negligible. However, observational studies have reported N2O undersaturation, suggesting that inland waters can act as N2O sinks due to net N2O consumption. This study leverages data from the National Ecological Observatory Network (NEON) and an existing global emission model to examine the prevalence of and controls on N2O undersaturation in streams, rivers, and lakes across scales and biomes. We find that N2O undersaturation is prevalent in the NEON data set (14%–30% of samples) and process‐based model outputs (38%), occurring across biomes and spatial scales. Failing to account for undersaturation in the NEON data set could result in an 100% overestimation of N2O emissions. These results show that consideration of N2O sink behavior is needed for accurate emission estimates. Plain Language Summary: Nitrous oxide (N2O) is a climate‐relevant greenhouse gas that is increasing in the atmosphere due to human activities. It also contributes to stratospheric ozone depletion. Inland waters (e.g., streams, rivers, and lakes) are significant, yet uncertain, sources of N2O to the atmosphere. In general, emission models assume that N2O is produced in and emitted from inland waters. However, field observations have shown that inland waters can also act as sinks of atmospheric N2O, potentially offsetting emissions. Understanding when and where inland waters act as N2O sinks is needed for accurate emission estimates. This study uses a large observational data set and an existing global emission model to explore when, where, and to what extent inland waters act as N2O sinks. The results show that N2O sink behavior is common and may significantly offset emissions. Key Points: Nitrous oxide (N2O) undersaturation in inland waters is prevalent, indicating that inland waters periodically act as sinks of atmospheric N2OPeriodic N2O sink behavior occurs at most monitored sites and the frequency of N2O sink behavior is invariant to ecosystem size or biomeN2O sink behavior has the strong potential to partially offset N2O emissions from inland waters [ABSTRACT FROM AUTHOR]

Animals are a critical component of biogeochemical cycles. While animal mediated fluxes of nutrients and energy have received considerable attention, the impacts of these fluxes on microbial community structure and function are comparatively understudied. Here, we investigated if freshwater mussel influences on biogeochemical cycling in stream sediment are accompanied by changes in sediment microbial community composition and ecoenzymatic activity, and if these relationships change under different nutrient regimes.We predicted that mussel effects on ecosystem function are reflected by modified sediment microbial communities. We hypothesized that if changes in either sediment ecoenzymatic function or microbial community composition are driven by mussel‐derived nutrient amendments, we should see muted changes in microbial community assemblages or function when a given nutrient is abundant. However, if microbial communities and function are influenced by other mussel functions, then we should see uniform changes regardless of nutrient availability.We transplanted freshwater mussels and natural river sediment to flow‐through mesocosms and monitored changes in microbial community composition over 1 week. Our results indicate that mussels always changed sediment microbial community composition, but the way communities changed was dependent on ambient nutrient concentrations.On the final day we measured the activity of ecoenzymes known to correlate to microbial function and nutrient availability. Mussels homogenized the stoichiometric ratios of ecoenzyme activities, indicating a consistent function of sediment microbes associated with freshwater mussels. Our results suggest that mussels may promote functional redundancy in sediment microbial communities and highlight the importance of animals in controlling biogeochemical transformations under changing nutrient conditions. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

I explore by way of a thought experiment the temporality of waterways in the context of restorative art interventions. As a substance that moves and gives form, and as a medium that retains and discharges, connects and divides, water that flows can make tangible the experiential flow of return and anticipation. Arguably, this bi‐directional structuring of time is pivotal to transformative and reparative action. If restoration means 'going back' to memories of ecologies and places, it does so with a generative thrust forward. This is the life‐enabling orientation of recuperation that I discern connects diverse phenomenological concepts: Deborah Bird Rose's 'multispecies knots of ethical time', the idea of 'afterness' as developed by Gerhard Richter, Gaston Bachelard's 'rhythmic time', and Gerald Vizenor's 'survivance'. I bring these concepts to: (a) artistic water restoration projects that make imaginable, palpable, and real sustainable human‐water relationships, with a focus on the public works in Sydney by Turpin + Crawford Studio; (b) perspectives on water and time that Australian Indigenous thinkers have shared during my ethnographic research; and (c) the re‐naturalization of a river in Germany's postindustrial Ruhr region. I propose that thinking with water ethically and recognizing its temporal diversity opens up perspectives on the deindustrialisation of rivers and other bodies of water. [ABSTRACT FROM AUTHOR]

Stable isotope analyses, specifically δ13C and δ15N, are useful tools increasingly used to understand ecosystem function, food web structures, and consumer diets. Although the iconic tigerfish Hydrocynus vittatus is regarded as an apex predator in southern African freshwater systems, little information is available regarding their feeding behavior and how this may change with growth or differ between ecosystems, with most information stemming from stomach content analyses (SCA). The aim of the present study was to address this lack of information through a baseline study of the diet of large and small tigerfish in various lentic and lotic ecosystems in South Africa using stable isotope methods. Fish and various food web components and food sources were collected from two river and two lake ecosystems in South Africa. The δ13C and δ15N values for all samples were determined and multivariate analyses and Bayesian analytical techniques applied to determine the feeding ecology of H. vittatus and how this may differ with size and habitat type. Analyses revealed a substantial difference in the type and abundance of food sources contributing to the diet of H. vittatus between ecosystems, most prominently between the lotic systems, where less dietary specialization was observed, and lentic systems where more specialization was observed. Furthermore, there was a distinct difference in diet between small and large tigerfish, especially in the lotic system, indicating an ontogenetic diet shift as tigerfish grow and further supporting previous SCA studies. This is the first study of its kind on the African continent for H. vittatus and the findings illustrate the value of stable isotope analysis in providing in‐depth information into the feeding ecology of consumers and how this may differ between size classes and habitat types. [ABSTRACT FROM AUTHOR]

This paper outlines the nature of microplastic contamination in rivers and the risks to freshwater fishes. We discuss how input sources influence the concentration and composition of microplastics and examine factors that subsequently influence their spatiotemporal dynamics in a river system. We then discuss how the distributions and assemblages of microplastics can impact the risk of interactions with fishes, and the processes associated with the internalisation of microplastic into the body and across the organs and tissues. Finally, we examine the physical and toxicological effects of microplastic exposure in fish species, with special attention directed towards impacts at environmentally relevant concentrations. This review integrates expertise in fluvial geomorphological processes and how they influence the movement and storage of microplastics in river channel environments at a range of scales. We combine this knowledge with expertise in fish ecology and biology to set out a new and integrated analysis of microplastic dynamics in rivers and how these microplastics interact with fish. The integration of knowledge from these fields allows us also to comment upon the microplastic risk to fish and other biota in river environments. [ABSTRACT FROM AUTHOR]

Ancient Chinese civilization was deeply rooted in a profound understanding of the environment. This understanding formed the primitive worship and unique culture of mountains and rivers, which found expression in both official and folk contexts. This essay delves into the significant influence of mountains and rivers on the site selection, positioning, and composition of ancient Chinese settlements. Through an in-depth analysis of cases, this study demonstrates that iconic mountain and river elements served as the foundation for determining the spatial locations of ancient Chinese settlements and the core references for designed landscapes. The settlement and surrounding mountains and rivers form a well-conceived integrated spatial composition, which threads the whole planning and construction process. As the determining factors for the spatial axes and forms of settlements, mountains and rivers also became the central objects of the feng shui theory. Therefore, the human geography of ancient China is not only a reflection of functions but also the result of the builders' diligent pursuit of spatial and cultural layouts. The study of the cultural genes allows for a deeper understanding of the cultural landscape of ancient China, leading to a commitment to protecting traditional settlements and their intact environmental systems. [ABSTRACT FROM AUTHOR]

Estimating discharges Q(x, t) from altimetric measurements only, for ungauged rivers (in particular, those with unknown bathymetry b(x)), is an ill-posed inverse problem. We develop here an algorithm to estimate Q(x, t) without prior flow information other than global open datasets. Additionally, the ill-posedness feature of this inverse problem is re-investigated. Inversions based on a Variational Data Assimilation (VDA) approach enable accurate estimation of spatio-temporal variations of the discharge, but with a bias scaling the overall estimate. This key issue, which was already highlighted in our previous studies, is partly solved by considering additional hydrological information (the drainage area, A (k m 2) ) combined with a Machine Learning (ML) technique. Purely data-driven estimations obtained from an Artificial Neural Network (ANN) provide a reasonably good estimation at a large scale ( ≈ 10 3 m). This first estimation is then employed to define the first guess of an iterative VDA algorithm. The latter relies on the Saint-Venant flow model and aims to compute the complete unknowns (discharge Q(x, t), bathymetry b(x), friction coefficient K(x, t)) at a fine scale (approximately 10 2 m). The resulting complete inversion algorithm is called the H2iVDI algorithm for "Hybrid Hierarchical Variational Discharge Inference". Numerical experiments have been analyzed for 29 heterogeneous worldwide river portions. The obtained estimations present an overall bias (less than 30% for rivers with similar characteristics than those used for calibration) smaller than previous results, with accurate spatio-temporal variations of the flow. After a learning period of the observed rivers (e.g. one year), the algorithm provides two complementary estimators: a dynamic flow model enabling estimations at a fine scale and spatio-temporal extrapolations, and a low complexity estimator (based on a dedicated algebraic low Froude flow model). This last estimator provides reasonably accurate estimations (less than 30% for considered rivers) at a large scale from newly acquired WS measurements in real-time, therefore making it a potentially operational algorithm. [ABSTRACT FROM AUTHOR]

In recent decades, water availability, water use, water sharing and freshwater supply for basic human and economic needs have become central scientific and humanitarian issues. With increasing water scarcity in many regions and increasing frequency of extreme flooding in other regions, there is a need to improve predictive capacity, to collect a large amount of information on key hydrological variables such as flows or water stocks in lakes and floodplains and to best combine these data with hydrological and hydrodynamic models. Most of the world's water demand relies on continental surface waters (rivers, lakes, wetlands and artificial reservoirs) while less on underground aquifers and seawater desalination. However, ground-based hydrological survey networks have steadily and drastically decreased worldwide over the last decades. In this context, current remote sensing techniques have been widely used by several countries for water resource monitoring purposes. In this paper, we present such remote sensing techniques, in particular satellite altimetry and imagery, and discuss how they became essential for the study of the water cycle and hydrological phenomena on a broad range of spatial and temporal scales. Large lakes, rivers and wetlands play a major role in the global water cycle and are also markers, integrators and actors of climate change at work on Earth. We show several examples chosen from the literature that perfectly highlight both current scientific and societal issues, as well as the crucial role of space techniques to monitor terrestrial surface waters. [ABSTRACT FROM AUTHOR]

The article focuses on R.D. Moore's comment on a forestry and salmonid habitat study, particularly addressing spatial comparisons in stream ecology. Moore highlights limitations in spatial comparisons, challenges in disentangling catchment characteristics from harvesting impacts, and proposes geoclimatic gradients over harvest history as explaining temperature patterns.

The oxidation of organic carbon contained within sedimentary rocks ("petrogenic" carbon, or hereafter OCpetro) emits nearly as much C2 as is released by volcanism, thereby playing a key role in the long-term global C budget. High erosion rates in mountains have been shown to increase OCpetro oxidation. However, these settings also export unweathered material that may continue to react in downstream floodplains. The relative importance of OCpetro oxidation in mountains versus floodplains remains difficult to assess as disparate methods have been used in the different environments. Here, we investigate the sources and fluxes of rhenium (Re) in the Rio Madre de Dios to quantify OCpetro oxidation from the Andes to the Amazon floodplain using a common approach. Dissolved rhenium concentrations (n = 131) range from 0.01 to 63 pmol L-1 and vary depending on lithology and geomorphic setting. We find that >75% of the dissolved Re derives from OCpetro oxidation and that this proportion increases downstream. We estimate that in the Andes, OCpetro oxidation releases 11.2+4.5/-2.8 tC km-2 y-1 of C2, which corresponds to ~41% of the total OCpetro denudation (sum of oxidized and solid OCpetro). A Re mass balance across the Rio Madre de Dios shows that 46% of OCpetro oxidation takes place in the Andes, 14% in the foreland-lowlands, and 40% in the Andean-fed floodplains. This doubling of OCpetro oxidation flux downstream of the Andes demonstrates that, when present, floodplains can greatly increase OCpetro oxidation and C2 release. [ABSTRACT FROM AUTHOR]

The detection of river boundaries is a crucial branch of the intelligent perception of unmanned surface vehicles (USVs), it can be used to determine the driving areas of USVs, and also to ensure driving safety by limiting the effective drivable areas of USVs in the river areas. Aiming to detect the boundaries of incompletely structured river channels, this study proposes a real‐time detection method for river boundaries based on a Light Detection and Ranging (LiDAR) sensor. The point clouds that are disturbed by the water surface noise are filtered firstly, and then the spatial and geometric features are extracted separately from the point cloud detected above the water surface. To prevent the error detection and missing detection, the boundary point information is predicted and calibrated in real time by Extended Kalman Filter (EKF). A planning track generation algorithm for coastal autonomous cruise without relying on high‐precision maps, and a heading and distance adaptive control method by Proportional‐Integral‐Derivative (PID), and different driving line generation methods for driving along the narrow river and wide river are proposed respectively. The experimental data verification of river boundary detection shows that the algorithm is accurate, real‐time, and robust. [ABSTRACT FROM AUTHOR]

Small streams dominate the hydrological network within Europe. In many regions, these waterbodies drain large areas of agricultural land and are vulnerable to pressures linked to livestock management, which can include direct livestock access. This study investigated the impacts of cattle access to watercourses on the contamination of streambed sediment with Escherichia coli (E. coli) in five agricultural catchments. Sediments were collected at cattle access sites and at areas upstream with no cattle access, in two time points in the livestock management cycle (mid-grazing and post-grazing season). Relatively high E. coli concentrations of 103 to 104 CFU g dry wt−1 were found at sites with no access in mid-grazing season. However, concentrations were significantly higher at sites with cattle access. E. coli was present, but in generally lower concentrations, in the post-grazing season. Additionally, the study found a significant negative relationship between the quality of the general riparian environment and E. coli bed sediment concentrations at the cattle access sites in the mid-grazing season, and a significant positive relationship between E. coli concentrations and estimated cattle density locally in post-grazing season. These findings indicate that allowing livestock access to watercourses can have implications for both water quality and human health. [ABSTRACT FROM AUTHOR]

In Australia the impacts of climate change are resulting in considerable water scarcity, a scenario affecting the green and blue spaces that provide well-recognized individual health benefits. However, far less is known about the social health benefits of these spaces, particularly for those residing in rural Australian river communities. In this geographic context, water issues are compounded by a dominant culture that privileges the commodification of water for agricultural purposes over other interests. Using an environmental justice perspective consistent with a green social work approach, this proof-of-concept study contributes a critical element to water debates by examining the cultural, recreational, and environmental meanings of water for the rural river community of Mildura. Results from an online mixed-methods questionnaire (N = 33) show that people privileged cultural meanings of water as fundamental to life, were concerned for river health, and felt marginalized in water debates. Findings suggest that understanding communities' hydrosocial relationships is key to environmentally and socially just water management and to individual, community, and environmental health. Social work can contribute to such environmental issues by working collaboratively to enable communities to exercise their voices and to advocate to decision makers to include consideration of environmental, social, and cultural impact. [ABSTRACT FROM AUTHOR]

The analysis of plant trait composition has raised significant interest among freshwater ecologists as a complementary approach for assessing the effects of environmental change on ecosystem functions. In this study, we investigated patterns of functional traits of the aquatic macrophyte assemblages of 74 lotic ecosystems of Greece, and we identified associations between species traits and environmental variables (hydromorphological and physicochemical parameters) through testing the hypothesis that the environmental features determine the spatial structure of traits. We allocated 12 traits to a total of 39 hydrophyte species, and we conducted RLQ and fourth corner analysis to explore relationships between species, trait composition, and environmental gradients. Based on the results of the RLQ, a hierarchical cluster analysis was conducted to identify groups of plants that share common trait characteristics. Plants were discriminated into five discrete groups based mostly on their life form (e.g., free-floating, rooted submerged etc.) and their ecological preference for nitrogen levels. Hydromorphological parameters had a higher contribution than physicochemical variables in explaining the total variance of the trait data, with water abstraction, channel substrate, and hydrologic alteration being the most important. Our analysis did not reveal significant bivariate relationships between single traits and environmental parameters, although the five groups of macrophyte assemblages appeared to associate with certain environmental gradients. Free-floating and emergent plants were related to higher concentrations of nutrients, whereas rooted submerged plants were related to higher oxygen concentration and increased pH. In addition, free-floating plants were highly associated with metrics of hydromorphological change. Our findings showed clear discrimination of macrophytes based on their functional composition and association of traits with environmental gradients. Thus, further research could explore whether macrophyte functional groups can serve as indicators of environmental change and the overall ecosystem health. [ABSTRACT FROM AUTHOR]

Sediments from three rivers in south-western Poland and their tributaries were used in a laboratory experiment on metal (Al, Cu, Ni, Cd, Zn, Fe, Mn) release. Metal migration was studied under different pH (pH 3.93, pH 7.29, pH 9.59) during 96 h. Al concentration was the highest in Bystrzyca and lowest in Strzegomka; other metal concentrations were highest in Nysa Szalona and lowest in Strzegomka. The values of pH and electrolytic conductivity increase throughout the experiment in acidic and neutral environments. Water pH decrease was observed under alkaline conditions, but conductivity reached higher values with time. The aluminum release showed an increase in values followed by a decrease. The highest aluminum amounts were released from the sediment from Nysa Szalona and the lowest from Strzegomka. The greatest aluminum migration was observed in the acidic medium. Similar observations were made for Mn and Zn: Strzegomka < Nysa Szalona < Bystrzyca. For Cu, Cd, Fe and Ni, the highest values were recorded in sediments in alkaline conditions. The amount of metals migrating from sediments to water remains at a similar level as presented by other researchers. More metals are released under acidic conditions. The most intensive migration of metals is noted at the beginning of the experiment. This experiment shows the existing trend of metals migration from the sediments to the over-bottom water, which is important from the point of view of the use of water for drinking purposes. Satisfactorily, the sediments in varied environments behave predictably enough that the quality of raw water under these conditions is not compromised, which is confirmed by environmental and health standards. The research performed concerns a specific area of southwestern Poland, for which this type of research has not been conducted. [ABSTRACT FROM AUTHOR]

This article explores the postwar racialization of socionatural metabolisms as Michigan consolidated its capacities to regulate water pollution in the St. Clair–Detroit River corridor. These unceded waters flow through the traditional territories of the Ojibwe, Odawa, Potawatomi, Mississauga, and Wyandot nations, as well as the heavily industrialized, urbanized, and racially segregated geographies of southeast Michigan. Drawing on archival records, I examine discursive constructions of White settler and Indigenous water metabolisms that coarticulated with Michigan's growing concern that unchecked water pollution posed a metabolic barrier to industrial manufacturing. I situate these representations against the state's emerging objective to reconcile two interconnected forms of waste: (1) the material degradation of water attributed to Michigan's advanced capitalist economy, and (2) the wasted economic potential long used to denigrate Indigenous societies that "failed" to extract capitalist value from nature. This case study demonstrates how Michigan's discursive approach to managing a potential crisis of capitalist reproduction also reconfigured the logic of improvement as the racial and economic basis for settler colonial authority over nature. "Improving" nature was not only about facilitating access to nature for capitalist production, but reproducing—indefinitely—the ecological conditions on which capitalist production relied. This article builds on two lines of inquiry in critical geographic scholarship exploring mutually constitutive relationships between race and socionatural metabolisms, and between settler colonialism and environmental degradation, to interrogate the postwar discourses flowing through water management in southeast Michigan, a region where water remains at the center of multiple racialized dispossessions and their ongoing contestation. [ABSTRACT FROM AUTHOR]

Nutrient uptake, storage, and release are critical ecosystem functions that affect carbon processing and food web dynamics. Yet, mechanisms controlling when ecosystems are net sinks or sources of nutrients are uncertain. Specifically, how nutrient supply ratios alter rates and ratios of net nutrient uptake and release is unclear. To assess whether net nitrogen (N) and phosphorus (P) uptake and release are linked to supply N:P, we experimentally enriched five forest streams at different N:P (target molar N:P range 2:1–128:1) for 2 years. We quantified net nutrient exchange (NNE) as the difference between the expected N and P fluxes assuming conservative transport (background concentrations plus experimental inputs) and the observed nutrient fluxes at the downstream end of each experimental stream reach. Supply N:P did not affect the magnitude of NNE for either N or P, but the likelihood of net N and P uptake was greatest at intermediate N:P supply (N:P = 99:1 and 55:1, respectively). Streams appeared to be highly flexible in their N:P uptake and release; the slopes between NNEN and NNEP within each stream increased with supply N:P. Furthermore, slopes comparing supply N:P to uptake and release N:P were near one (0.98 ± 0.06 SE and 0.82 ± 0.13 SE, respectively), indicating a high degree of flexibility. Overall, we found greater stoichiometric flexibility than has been shown in short-term nutrient-addition experiments. We suggest that this flexibility results from changes in nutrient recycling within biofilms or changes in community structure, which may take longer to manifest than the duration of shorter-term experiments. [ABSTRACT FROM AUTHOR]

The present era of climate change and expanding population requires major improvements in sustained observation of global river discharge. Floods and droughts are affecting food supplies, and suspected long‐term trends require appropriate data for evaluation. Orbital remote sensing can address this observational need. Here we use satellite Ka‐ (36.5 GHz) and L‐band (1–2 GHz) passive microwave radiometry (PMR) to monitor river discharge changes and determine what size rivers can be measured and the frequencies and polarization configurations that yield the most robust results. Selected satellite gauging reaches (SGRs) can be measured at near‐daily intervals from 1998 to present (Ka‐band) and 2010 to present (L‐band). The SGRs are 10–36 km in length; the dynamic proportion of water surface area within each varies with river discharge. Due to contrasting dielectric properties, water and land emit different intensities of microwave radiation; thus emission from a mixed water/land pixel decreases as the proportion of water within the pixel increases. Depending on the river and floodplain morphology, water flow area can be a robust indicator of discharge and the microwave sensors can retrieve daily discharge to ±20%. Instead of spatial resolution, it is the sensor measurement precision, geolocation accuracy, and channel and floodplain morphology that most strongly affect accuracy. Calibration of flow area signals to discharge can be performed using nearby ground stations (even if now discontinued) or by comparison to hydrologic modeling. Plain Language Summary: River discharge (flow rate) measurements are critical to hydrology research and water resource management worldwide. Such data have long been collected on the ground at gauging stations, but environmental monitoring in an era of climate change and expanding population now requires major improvements in its quantity and quality. River flow area can be used to monitor streamflow variation, and such area observations are available from a variety of orbital satellite sensors. Passive microwave information offers the advantage of frequent (near daily) sampling with little interference from cloud cover. Flow area is monitored for defined satellite gauging reaches (SGRs) measuring 10–36 km in length depending on the sensor and band used. As demonstrated by comparison to ground gauging stations, Ka‐band and L‐band microwave information can both be used successfully. Ka‐band data offer higher spatial resolution and a time series extending back to 1998. L‐band SGR data from the SMAP polarimetric radiometer are less sensitive to small geolocation errors, and may provide better results especially for the larger rivers or those with forested floodplains. Key Points: Climate change and an expanding global population require major improvements in sustained observation of global river dischargePassive microwave radiometry from several satellite sensors can retrieve river discharge and watershed runoff at globally‐distributed satellite gauging reaches (SGRs)Ka‐band and L‐band information provides accurate and useful discharge time series to ±20% at well‐located SGRs [ABSTRACT FROM AUTHOR]

This article explores continuities and changes in the damming of rivers in the global South. By the 2000s, the infrastructural promises of large dams seemed exhausted. Yet, currently dams are making a strong comeback with new justifications highlighting their capacity to produce low-carbon energy and climate-proofed waterscapes, while the harms they generate are being presented as fixable. Through cases from the Mekong (Laos and Cambodia), and the Grijalva (Mexico) River Basins, we problematize these claims. Despite changes in the aspirations and agencies that foster damming, obdurate dam materialities and the new profit-maximizing operation modes provoke violent continuities of infrastructural harms and hinder the repurposing of dams to serve climate combat. Neoliberalised dams even augment climate vulnerabilities, as the more volatile rivers increasingly exceed their ordering capacities. We also show how the new dam assemblages continue dispossessing riverine residents while divergently strengthening corporate and state powers and obscuring relations of responsibility. [ABSTRACT FROM AUTHOR]

Gravity and magnetic field datasets coupled with Shuttle Radar Topography Mission (SRTM) digital elevation data over north-western Nigeria were interpreted to delineate subsurface and surface structures, and determine their influence on the drainage system within Sokoto Basin and its surrounding environment. The Improved Logistic Filter and Euler Deconvolution techniques were applied to the residual fields of the gravity and magnetic data to delineate lineaments and their depths of occurrence, respectively. The lineaments mapped from gravity and magnetic data revealed a major N–S and NE–SW, and W–E trend respectively and in several cases were aligned with surface lineaments from the SRTM digital elevation data. The results revealed that the drainage channel of Rivers Niger, Sokoto, Rima, Zamfara, Ka, Kasanu, Gagere, Kuromoni, Malendo and Kontagora are closely aligned with several lineaments emanating from the underlying basement. The 2-D forward models confirmed the presence of these lineaments and delineated intrusives within Sokoto Basin. This study concluded that the drainage system of north-western Nigeria is structurally controlled. [ABSTRACT FROM AUTHOR]

Alluvial rivers are conveyor belts of fluid and sediment that provide a record of upstream climate and erosion on Earth, Titan, and Mars. However, many of Earth’s rivers remain unsurveyed, Titan’s rivers are not well resolved by current spacecraft data, and Mars’ rivers are no longer active, hindering reconstructions of planetary surface conditions. To overcome these problems, we use dimensionless hydraulic geometry relations—scaling laws that relate river channel dimensions to flow and sediment transport rates—to calculate in-channel conditions using only remote sensing measurements of channel width and slope. On Earth, this offers a way to predict flow and sediment flux in rivers that lack field measurements and shows that the distinct dynamics of bedload-dominated, suspended load-dominated, and bedrock rivers give rise to distinct channel characteristics. On Mars, this approach not only predicts grain sizes at Gale Crater and Jezero Crater that overlap with those measured by the Curiosity and Perseverance rovers, it enables reconstructions of past flow conditions that are consistent with proposed long-lived hydrologic activity at both craters. On Titan, our predicted sediment fluxes to the coast of Ontario Lacus could build the lake’s river delta in as little as ~1,000 y, and our scaling relationships suggest that Titan’s rivers may be wider, slope more gently, and transport sediment at lower flows than rivers on Earth or Mars. Our approach provides a template for predicting channel properties remotely for alluvial rivers across Earth, along with interpreting spacecraft observations of rivers on Titan and Mars. [ABSTRACT FROM AUTHOR]

Mapping river water quality at a basin scale with satellite image data represents a tremendous technical challenge, since traditional empirical remote sensing models calibrated for specific reaches of a river cannot be applied to all the rivers and streams in the basin with an adequate prediction accuracy. In this study, we developed a multi-predictor ensemble model to map and assess water turbidity for all rivers and streams in the Tombigbee River Basin with Landsat 8 multispectral images. Coincident with Landsat 8 satellite overpass on 2 May 2019, we conducted boat-based water quality data collection in the confluence area of Tombigbee River and Black Warrior River near the city of Demopolis, Alabama. Based on the coincident satellite image and field water samples, we calibrated and evaluated the multi-predictor ensemble model, which consists four component empirical models. Our evaluations suggest that the multi-predictor ensemble model can improve turbidity estimation accuracy by 79% in comparison with the best traditional empirical model. More importantly, our multi-predictor ensemble model can be applied to other river and stream reaches across three major sub-basins with a high prediction accuracy. With the multi-predictor ensemble model, we derived a turbidity map for all rivers and streams with a width greater than 90 m in the basin, by processing three Landsat 8 image scenes. This basin-wide turbidity map indicates that the turbidity of rivers and streams exhibits longitudinal gradients and distinct spatial trends within the basin, which were related to the basin land cover/land use, hydrometeorological condition, and the spatial distribution of dams. Owing to its strong spatial transferability and high prediction accuracy, the ensemble model, in conjunction with synoptic multispectral satellite image data, is recommended as an effective and efficient tool for mapping and monitoring river and stream water quality at a large basin or regional scale. [ABSTRACT FROM AUTHOR]

Industrial‐scale metal mining has long been a feature of developing economies. Processing ores to recover minerals has generated large quantities of waste rock, tailings and contaminants. Mining‐related deposits, along with associated soil and water geochemistry, river modifications and other environmental changes, are a product of the nature, scale and intensity of past operations. These artefacts of historical mining create anthropogenic landscapes that extend far beyond individual sites due to the dispersal of mine waste by rivers and pose enduring threats to human and ecosystem health. Their presence and significance, however, are often overlooked by heritage and environmental managers. To be acknowledged as artefacts of the historical mining industry, landscape features must be identified and characterised with reference to the human activities that triggered their formation. This requires an interdisciplinary approach that incorporates anthropogenic landscape change at a regional scale. In this paper, we integrate archaeological, geomorphological and geochemical evidence to identify and analyse mining‐related changes to the Loddon River valley in Victoria, Australia. Nineteenth‐century gold mining caused extensive erosion of creeks and gullies and mobilised sediments that filled channels and spread over floodplains. In addition, tailing deposits concentrated arsenic at levels significantly above environmental background conditions. Recognising these legacies of historical mining is vital to understanding mining heritage and to managing healthy rivers, environments and communities. [ABSTRACT FROM AUTHOR]