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The objective was to evaluate the feasibility of measuring bathymetry using airborne green LiDAR in long and variable river reaches (4 km or more), across three rivers with varying gradients, water depths and light penetration (3.5–10 m), using four alternative LiDAR sensors. The accuracy of green LiDAR data was compared to in situ measurements collected by stratified transect point sampling and Multibeam bathymetry. Factors potentially limiting the feasibility of green LIDAR in rivers were explored. If remote sensing signals were reflected by the riverbed, the sensors generally provided elevation data consistent with in situ elevation measurements, indicating high accuracy (±10 cm) across different hydraulic conditions. The loss of green LiDAR data was mainly a consequence of limited signal water penetration capability, that is, water clarity. Secchi depth was a proxy variable strongly associated with green LiDAR penetration capability across rivers. Data loss was low up to the Secchi depth but increased rapidly thereafter. Surface water turbulence ('white water') and dark riverbed vegetation also increased green LiDAR signal loss. Sensors with lower point density and therefore less spatial resolution had more signal strength and therefore penetrated deeper water. However, with increasing coverage of surface turbulence ('white water'), the importance of high point density also increased. Signal power should be balanced with signal density (spatial resolution), depending on river characteristics and project objectives. We conclude that remote sensing green LiDAR bathymetry is a robust method that efficiently provides accurate elevation data across rivers with different hydraulic conditions and water depths. [ABSTRACT FROM AUTHOR]

The objective of the current research was to examine the water quality of the River Ravi and the River Sutlej, with a specific focus on potentially toxic elements (PTEs). Additionally, we sought to monitor the sources of pollution in these rivers by gathering samples from the primary drains that carry industrial and municipal waste into these water bodies. Furthermore, we aimed to evaluate the impact of PTEs in surface water on groundwater quality by collecting groundwater samples from nearby populated areas. A total of 30 samples were collected from these three sources: rivers (6 samples), drains (9 samples), and groundwater (15 samples). The analysis revealed that the levels of PTEs in the samples from these three resources having a mean value: arsenic (As) 23.5 µg/L, zinc (Zn) 2.35 mg/L, manganese (Mn) 0.51 mg/L, lead (Pb) 6.63 µg/L, and chromium (Cr) 10.9 µg/L, exceeded the recommended values set by the World Health Organization (WHO). Furthermore, PTEs including (As 84%), (Zn 65%), (Mn 69%), (Pb 53%), (Cr 53%), and (Ni 27%), samples were beyond the recommended values of WHO. The results of the Principal Component Analysis indicated that surface water and groundwater exhibited total variability of 83.87% and 85.97%, respectively. This indicates that the aquifers in the study area have been contaminated due to both natural geogenic factors and anthropogenic sources. These sources include the discharge of industrial effluents, wastewater from municipal sources, mining activities, agricultural practices, weathering of rocks, and interactions between rocks and water. Spatial distribution maps clearly illustrated the widespread mobilization of PTEs throughout the study area. Furthermore, a health risk assessment was conducted to evaluate the potential adverse health effects of PTEs through the ingestion of drinking groundwater by both children and adults. Health risk assessment result show the mean carcinogenic values for As, Cr, Pb and Ni in children are calculated to be (1.88E-04), (2.61E-04), (2.16E-02), and (5.74E-05), respectively. Similarly, the mean carcinogenic values for the above mentioned PTEs in adults were recorded to be (2.39E-05), (3.32E-05), (1.19E-03), and (7.29E-06) respectively. The total hazard index values for As, Zn, Cr, Pb, Mn, Cu, and Ni in children were observed to be (9.07E + 00), (9.95E-07), (4.59E-04), (5.75E-04), (4.72E-05), (2.78E-03), and (5.27E-05) respectively. The analysis revealed that As has an adverse effect on the population of the study area as compared to other PTEs investigated in this study. [ABSTRACT FROM AUTHOR]

India boasts of a vast freshwater resource network (rivers, wetlands, and groundwater), which has unique ecological, social and economic values associated with it. Despite their importance for both people and biodiversity, its freshwater ecosystems (FWEs) are heavily impacted through multiple factors such as pollution, overexploitation, habitat loss/modification and climate change. India is also among the hotspots of water resource overuse that has caused a serious decline in freshwater availability.Given that healthy FWEs lie at the centre for supporting the country's ecology, health, economy, livelihoods and ultimately achieving multiple policy goals, it is crucial that holistic and focused efforts are made to protect, conserve, and restore all types of FWEs.We call for an urgent and a greater focus on implementing conservation actions for FWEs in India and suggest the following strategy to enhance focus on their conservation: (1) establishing a shared freshwater conservation vision at a national scale, (2) developing and including national freshwater conservation goals within global efforts, (3) conducting simultaneous conservation action planning at regional scales and (4) bridge planning to implementation gap by strengthening key enabling conditions: i) mainstream FWE conservation within key existing governance instruments, ii) secure sustainable conservation funding, iii) improve data access and knowledge translation; iv) create national awareness around importance of FWEs; v) facilitate collaboration among key actors. [ABSTRACT FROM AUTHOR]

Introduction: Information on spatial patterns of water depth in river channels is valuable for numerous applications, but such data can be difficult to obtain via traditional field methods. Ongoing developments in remote sensing technology have enabled various image-based approaches for mapping river bathymetry; this study evaluated the potential to retrieve depth from multispectral images acquired by an uncrewed aircraft system (UAS). Methods: More specifically, we produced depth maps for a 4 km reach of a clearflowing, relatively shallow river using an established spectrally based algorithm, Optimal Band Ratio Analysis. To assess accuracy, we compared image-derived estimates to direct measurements of water depth. The field data were collected by wading and from a boat equipped with an echo sounder and used to survey cross sections and a longitudinal profile. We partitioned our study area along the Sacramento River, California, USA, into three distinct sub-reaches and acquired a separate image for each one. In addition to the typical, self-contained, per-image depth retrieval workflow, we also explored the possibility of exporting a relationship between depth and reflectance calibrated using data from one site to the other two sub-reaches. Moreover, we evaluated whether sampling configurations progressively more sparse than our full field survey could still provide sufficient calibration data for developing robust depth retrieval models. Results: Our results indicate that under favorable environmental conditions like those observed on the Sacramento River during low flow, accurate, precise depth maps can be derived from images acquired by UAS, not only within a sub-reach but also across multiple, adjacent sub-reaches of the same river. Discussion: Moreover, our findings imply that the level of effort invested in obtaining field data for calibration could be significantly reduced. In aggregate, this investigation suggests that UAS-based remote sensing could facilitate highly efficient, cost-effective, operational mapping of river bathymetry at the reach scale in clear-flowing streams. [ABSTRACT FROM AUTHOR]

Pollution of water bodies with heavy metals can lead to the death of fish and other aquatic organisms, a decrease in biodiversity and a threat to ecosystems, emphasising the importance of preserving the natural environment; pollution of water bodies can have serious economic consequences, in particular, a decrease in profits from fishing, tourism, and other activities related to water use, which requires the development of water management strategies. The purpose of the study was to determine the general trends in the content of heavy metals in the surface waters of the Teteriv River and fattening pond No. 1 of the LLC "SHF INTERRYBHOSP". Water samples were taken at the stream of the Teteriv River (Vidsichne Reservoir) and in the fattening pond No. 1 at a depth of 0.2-0.5 m from the surface for further laboratory analysis of the content of heavy metal ions (HM). The atomic absorption method of analysis was used to study water. Laboratory studies of surface waters in the Teteriv River and pond were performed according to the following indicators: hydrogen index (pH), lead, cadmium, manganese, zinc, and iron content. The results of the study of the content of heavy metals in the Teteriv River are presented, which showed that the content of such heavy metals as: Pb, Cd, Mn, Zn and Fe, in river water, with the exception of iron, exceed the limits of maximum admissible values of water quality indicators for fishery water bodies. Background HM indicators from fattening pond No. 1 did not show an excess of the MAC (maximum admissible concentration). High concentrations of lead, cadmium, manganese, and iron are explained by powerful anthropogenic pollution, the source of which is agricultural and industrial complexes of Zhytomyr Oblast. The results can be used to establish effective monitoring of water quality in reservoirs and develop strategies to reduce pollution in aquatic ecosystems. [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]

This study aimed to optimize the methods for sampling and analyzing methylmercury (MeHg) concentrated within diffusive gradients in thin films (DGT) and its application to different water bodies. We explored the elution solution for MeHg, comprised of 1.13 mM thiourea and 0.1M HCl, optimizing its volume to 50 mL. In addition, we found that it is necessary to analyze the entire extraction solution after adjusting its pH, to ensure completion of the ethylation reaction. The DGT samplers were deployed in two distinct aquatic environments (i.e., Okjeong Lake and Nakdong River) for up to 6 weeks, and this study demonstrated to predict the time-weighted average concentration with a diffusion coefficient of 7.65 × 10−6 cm2 s−1 for MeHg in the diffusive gel. To assess the diffusive boundary layer (DBL) effects, the DGT samplers with different agarose diffusive gel thickness were deployed. The mass of MeHg accumulated in the DGT resin at a given time decreased with increasing diffusive gel thickness, because of creating longer diffusion pathways within thicker gels. The labile MeHg concentration estimated by the DGT in Okjeong Lake and Nakdong River are found in the range of 61–111 and 55–105 pg L−1, respectively, which were found to be similar to the grab sampling data. Additionally, this study evaluated depth-dependent MeHg in Okjeong Lake. The vertical profile results showed that the concentration of MeHg at the depth of 2.3 and 15.7 m are about 1.5 and 4.6 times of the DGT installed at 0.3 m of the surface layer, respectively, suggesting potential mercury methylation in deep waters. These findings have practical implications for predicting bioavailability, assessing risks, and formulating strategies for water body management and contamination remediation. [ABSTRACT FROM AUTHOR]

Iron (Fe) is one of the main nutrients present in dissolved, suspended, and colloidal states in river water. Predicting the composition and size of dissolved Fe compounds is crucial for assessing water quality. In this stud, we used a combination of physical methods (filtration), chemical techniques (ion exchange chromatography), and thermodynamic modeling (Visual MINTEQ) to characterize dissolved Fe speciation in boreal organic-rich rivers across a sizable south–north transect. We chose contrasting rivers with a predominance of either allochthonous or autochthonous organic compounds. We found that the dissolved organic matter (DOM) in the studied rivers varies in molecular weights and the degree of humification. Regardless of the climate parameters of the river watershed, the dominant status of dissolved Fe during the summer low-water period was essentially colloidal and dominated by anionic complexes of the type [MeL]n−. [ABSTRACT FROM AUTHOR]

There is an accumulation of toxic metal ions in an aquatic habitat that modifies the physical and chemical characteristics of water, posing a threat to aquatic organisms. The fish's body absorbs heavy metals through the gills, dorsal surface, and gastrointestinal system when they eat foodstuff that has high levels of these metals. Zinc, Lead, Mercury, Copper, Arsenic, Nickel, chromium and cadmium are the primary heavy metal contaminants responsible for inducing toxicity in fish. Oxidative stress, or oxidative damage, is the primary chemical process responsible for metal poisoning. Stress undermines a low immune system, leading to harm to organs and tissues, developmental irregularities, and reduced reproductive capacity. Due to the copious availability of vitamins, proteins, and fatty acids such as omega-3 found in fish, individuals are inclined to consume seafood as their primary nutritional source. Consequently, the aggregation of toxic metallic elements in fish tissues has a direct impact on people, causing detrimental effects that accelerate the onset of various diseases. To effectively enforce aquatic conservation regulations and protect human lives, it is imperative to investigate the origins of toxic metals and their detrimental effects on the health of fish. [ABSTRACT FROM AUTHOR]

The annual distribution characteristics of river runoff in arid regions have significant implications for water resource stability and management. Based on the mountain runoff data from 1965 to 2018, this study examines the annual change characteristics of monthly runoff of the Shiyang River Basin, Heihe River Basin, and Shule River Basin in the Hexi Corridor, Northwest China. Many indexes are used and analyzed, including the coefficient of variance, the complete regulation coefficient, the concentration degree and concentration period, the magnitude of change, the skewness coefficient, and the kurtosis coefficient of the annual distribution curves. The results reveal the following: (1) The inhomogeneity of annual runoff distribution in the Taolai River and the rivers to the west of it, except the Shiyou River, show an increasing trend. Conversely, the inhomogeneity of the rivers to the east of the Taolai River generally show a downward trend, but the coefficient of variance value is still very high. (2) In the Shiyang River Basin, the annual distribution of the concentration period is characterized by a relatively discrete pattern. Conversely, the Heihe River Basin exhibits a relatively concentrated pattern, and the distribution pattern of the Shule River Basin is quite different. Notably, all concentration periods in the three basins have shifted backward after the 2000s. (3) The Shiyang River Basin exhibits disordered annual distribution curves of runoff in different years. In contrast, the Heihe River Basin presents a typical ‘single-peak’ pattern with a prominent right-skewed. The Shule River Basin has regular distribution curves, with a gradually significant ‘double-peak’ pattern from east to west. Overall, there has been a slight change in runoff in the Shiyang River Basin, while the Heihe River Basin and Shule River Basin have experienced significant increases in runoff. The annual distribution curves of runoff in the Liyuan River and the rivers to the east of it exhibit a gentle peak pattern, and the appearance probability of extreme runoff during the year is low. Conversely, the rivers to the west of the Liyuan River, excluding the Danghe River, display a sharp peak and thick tail pattern, indicating that the appearance probability of extreme runoff during the year is high. These findings have practical implications for the planning and management of water resources in the Hexi Corridor. Moreover, they provide a solid foundation for predicting future changes in regional water resources. [ABSTRACT FROM AUTHOR]

This paper discusses water in Afghanistan from the late nineteenth century through the early twenty-first century. This broad chronology is periodized using the historical themes of colonialism, nationalism, international developmentalism, and global warfare. Modern hydraulic technology arrived in the domestic architecture of Kabuli state elites beginning in the 1860s and accelerating greatly in the 1890s. The first decades of the twentieth were marked by continuing developments regarding palatial hydrology (pools, fountains, etc.) and new forms of modern hydraulic engineering (piped water, dams and bridges) primarily in and around Kabul involving the Kabul river and its tributaries. The middle decades of the twentieth century involved substantial engagement of rivers throughout country under the various ideological and material regimes of international development sponsored by the US, USSR and a number of other global actors and sanctioned by local political elites who became increasingly dependent on the global system. The decades surrounding the year 2000 have been marked by intense and sustained overt and covert global warfare. The effects of war on the environment of Afghanistan from the perspective of Human Rights, particularly Afghan Peoples' Rights to Water, constitute the final section of the paper. [ABSTRACT FROM AUTHOR]

In the process of production or processing of materials by various methods, there is a need for a large volume of water of the required quality. Today in many regions of the world, there is an acute problem of providing industry with water of a required quality. Its solution is an urgent and difficult task. The water quality of surface water bodies is formed by a combination of a large number of both natural and anthropogenic factors, and is often significantly heterogeneous not only in the water area, but also in depth. As a rule, the water supply of large industrial enterprises is located along the river network. Mergers are the most important nodes of river systems. Understanding the mechanism of transport of pollutants at the confluence of rivers is critical for assessing water quality. In recent years, thanks to the data of satellite images, the interest of researchers in the phenomenon of mixing the waters of merging rivers has increased. The nature of the merger is influenced by the formation of transverse circulation. Within the framework of this work, a study of vorticity, as well as the width of the mixing zone, depending on the distance from the confluence, the speeds of the merging rivers and the angle of confluence was carried out. Since the consumer properties of water are largely determined by its chemical and physical indicators, the intensity of mixing, determined largely by the nature of the secondary circulation, is of fundamental importance for assessing the distribution of hydrochemical indicators of water quality in the mixing zone. These characteristics are important not only for organizing water intake for drinking and technical purposes with the best consumer properties, but also for organizing an effective monitoring system for confluence zones. [ABSTRACT FROM AUTHOR]

Abstract: The San Francisco Estuary, in central California, has several long-running monitoring programs that have been used to reveal human-induced changes throughout the estuary in the last century. Here, we pair synoptic records of particulate organic matter (POM) composition from 1990–1996 and 2007–2016 with more robust long-term monitoring program records of total suspended sediment (TSS) concentrations generally starting in the mid-1970s to better understand how POM and TSS sources and transport have shifted. Specifically, POM C:N ratios and stable isotope values were used as indicators of POM source and to separate the bulk POC pool into detrital and phytoplankton components. We found that TSS and POC sources have shifted significantly across the estuary in time and space from declines in terrestrial inputs. Landward freshwater and brackish water sites, in the Delta and near Suisun Bay, witnessed long-term declines in TSS (32 to 52%), while seaward sites, near San Pablo Bay, recorded recent increases in TSS (16 to 121%) that began to trend downwards at the end of the record considered. Bulk POM C:N ratios shifted coeval with the TSS concentration changes at nearly all sites, with mean declines of 12 to 27% between 1990–1996 and 2007–2016. The widespread declines in bulk POM C:N ratios and inferred changes in POC concentrations from TSS trends, along with the substantial declines in upstream TSS supply through time (56%), suggest measurable reductions in terrestrial inputs to the system. Changes in terrestrial TSS and POM inputs have implications for biotic (e.g., food web dynamics) and abiotic organic matter cycling (e.g., burial, export) along the estuarine continuum. This work demonstrates how human-generated environmental changes can propagate spatially and temporally through a large river-estuary system. More broadly, we show how underutilized monitoring program datasets can be paired with existing (and often imperfect) synoptic records to generate new system insight in lieu of new data collection.

This paper presents a reassessment of mound visibility through the analysis of Halvdanshaugen, a substantial Iron Age mound in Norway. In line with conventional views, the mound's visibility covers a considerable swath of the surrounding terrain, although views are limited by topographic features from certain directions and specific parts of the landscape. A refined viewshed analysis, incorporating vegetation as a visual barrier, however, suggests that the mound's visual impact extends no more than a few hundred meters from its base. This sees the mound placed in an enclosed setting which alters the mound’s visual characteristics, emphasizing details of both the mound and activities nearby. In contrast to traditional interpretations that emphasize landscape-wide symbolism, this study advocates for a more reflective perspective, and calls for a multi-sensory understanding of the fluid relationship between mound and landscape. It rejects the idea of universal placement rules and proposes more contextual interpretations that acknowledge the diversity observed in mound construction and use.

The contribution of citizen scientists to environmental monitoring is notably increasing significantly. Governments worldwide establish Water Users Associations (WUAs) as a good practice model to implement Integrated Water Resource Management (IWRM) at local levels. These associations target different stakeholders depending on the expected outcome. However, their effectiveness, especially in East Africa, can only be determined case by case. In Kenya, Water Resources Users Associations are registered, voluntary community groups whose members are water users and land owners. Similarly, in Uganda, community-based initiatives exist, especially along degraded rivers, involving cooperation between local communities and regional water authorities. On the contrary, it has been reported that in Tanzania, many community initiatives created become non-functional within 2–3 years of induction. In general, the main responsibility of Water Users Associations or its equivalent is to manage and conserve water resources for sustainable uses. In most cases, water quality monitoring by communities through citizen science is limited to the visual appearance of water in the river channel. While this can indicate the water’s esthetic value, it is insufficient for assessing the ecological status of rivers, which is influenced by a variety of physical, chemical, biological, and socioeconomic factors. The use of bioindicators has been advocated as a feasible method for community-based water quality river monitoring. Therefore, this review explores the commonly used bio-indicators and bio-assessment tools for river health assessment and their complexities when using a biomonitoring community-based approach through citizen science. Tolerance and intolerance macroinvertebrate and fish metric protocols that utilize identification keys have been recommended. These protocols are designed to be user-friendly and require minimal taxonomic expertise, making them easy for community volunteers to use with minimal basic training. The sustainability of these citizen science initiatives relies on the motivation of volunteers, the frequency of monitoring activities, and collaboration with researchers and government agencies. These initiatives not only facilitate environmental monitoring but also foster community engagement and awareness regarding the ecological status of rivers, thereby addressing knowledge and data gaps necessary for effective policy-making. This approach provides a practical model for environmental stewardship and participatory resource management in East Africa.

In this study, we explored how barriers such as dams have affected the longitudinal connectivity of riverine habitats from the perspective of potamodromous fish. For this purpose, connectivity changes are investigated in the central part of the Austrian Danube system, where the national reporting for the EU Water Framework Directive provides detailed information on the position and characteristics of barriers as well as the distribution range of native fish species. This assessment is based on an estimation regarding the quantitative upstream and downstream passability of individual barriers, where we further investigate three different passability scenarios to account for uncertainties. We then apply several combinations of passability scenarios and assumptions on dispersal distances to calculate a series of network-based reach and catchment connectivity indices. On average, the estimation of barrier passability indicated a high downstream passability, while upstream passability was substantially lower across scenarios. Furthermore, existing fish passes were estimated to have increased passability on average between 20 % and 24 %. Overall, the results indicated a strong effect of barriers on the longitudinal connectivity of the investigated river network. Catchment scale indices revealed a loss of connectivity, which increased with dispersal distance. Reach connectivity indices displayed a strong disruption of the natural connectivity gradient along the river network and indicated that individual river reaches have, on average, become more isolated in addition to the overall decrease in connectivity. The average loss of connectivity across scenarios was estimated at 72 % (SD = 16 %) when taking into account all connections to other reaches and 66 % (SD = 7 %) when only connections to upstream reaches were considered. We conclude that longitudinal connectivity in the Austrian Danube system is still severely compromised, making it increasingly challenging for potamodromous fish species to complete their life cycle. This issue is further amplified by the severe loss of fish habitats as a consequence of river engineering.

High-frequency water quality measurements in streams and rivers have expanded in scope and sophistication during the last two decades. Existing technology allows in situ automated measurements of water quality constituents, including both solutes and particulates, at unprecedented frequencies from seconds to subdaily sampling intervals. This detailed chemical information can be combined with measurements of hydrological and biogeochemical processes, bringing new insights into the sources, transport pathways, and transformation processes of solutes and particulates in complex catchments and along the aquatic continuum. Here, we summarize established and emerging high-frequency water quality technologies, outline key high-frequency hydrochemical data sets, and review scientific advances in key focus areas enabled by the rapid development of high-frequency water quality measurements in streams and rivers. Finally, we discuss future directions and challenges for using high-frequency water quality measurements to bridge scientific and management gaps by promoting a holistic understanding of freshwater systems and catchment status, health, and function.

Roughly half of the human population lives near the coast, and coastal water pollution (CWP) is widespread. Coastal waters along Tijuana, Mexico, and Imperial Beach (IB), USA, are frequently polluted by millions of gallons of untreated sewage and stormwater runoff. Entering coastal waters causes over 100 million global annual illnesses, but CWP has the potential to reach many more people on land via transfer in sea spray aerosol (SSA). Using 16S rRNA gene amplicon sequencing, we found sewage-associated bacteria in the polluted Tijuana River flowing into coastal waters and returning to land in marine aerosol. Tentative chemical identification from non-targeted tandem mass spectrometry identified anthropogenic compounds as chemical indicators of aerosolized CWP, but they were ubiquitous and present at highest concentrations in continental aerosol. Bacteria were better tracers of airborne CWP, and 40 tracer bacteria comprised up to 76% of the bacteria community in IB air. These findings confirm that CWP transfers in SSA and exposes many people along the coast. Climate change may exacerbate CWP with more extreme storms, and our findings call for minimizing CWP and investigating the health effects of airborne exposure.

Conservation of endangered fishes commonly includes captive breeding, applied research, and management. Since 1996, a captive breeding program has existed for the federally threatened and California endangered Delta Smelt Hypomesus transpacificus, an osmerid fish endemic to the upper San Francisco Estuary. Although this program serves as a captive refuge population, with experimental releases being initiated to supplement the wild population, it was uncertain how individuals would survive, feed, and maintain condition outside hatchery conditions. We evaluated this and the effects of three enclosure designs (41% open, 63% open, and 63% open with partial outer mesh wrap) on growth, survival, and feeding efficacy of cultured Delta Smelt at two locations (Sacramento River near Rio Vista, CA and in Sacramento River Deepwater Ship Channel) in the wild. Enclosures exposed fish to semi-natural conditions (ambient environmental fluctuations and wild food resources) but prevented escape and predation. After four weeks, survival was high for all enclosure types (94-100%) at both locations. The change in condition and weight was variable between sites, increasing at the first location but decreasing at the second location. Gut content analysis showed that fish consumed wild zooplankton that came into the enclosures. Cumulatively, results show that captive-reared Delta Smelt can survive and forage successfully when housed in enclosures under semi-natural conditions in the wild. When comparing enclosure types, we observed no significant difference in fish weight changes (p = 0.58-0.81 across sites). The success of housing captive-reared Delta Smelt in enclosures in the wild provides preliminary evidence that these fish may be suitable to supplement the wild population in the San Francisco Estuary. Furthermore, these enclosures are a new tool to test the efficacy of habitat management actions or to acclimate fish to wild conditions as a soft release strategy for recently initiated supplementation efforts.

The COVID-19 global pandemic led to major upheavals in daily life. As a result, mental health has been negatively impacted for many, including college students who have faced increased stress, depression, anxiety, and social isolation. How we think about the future and adjust to such changes may be partly mediated by how we situate our experiences in relation to the pandemic. To test this idea, we investigate how temporal framing influences the way participants think about COVID life. In an exploratory study, we investigate the influence of thinking of life before versus during the pandemic on subsequent thoughts about post-pandemic life. Participants wrote about their lives in a stream-of-consciousness style paradigm, and the linguistic features of their thoughts are extracted using Linguistic Inquiry and Word Count (LIWC). Initial results suggest principal components of LIWC features can distinguish the two temporal framings just from the content of their post-pandemic-oriented texts alone. We end by discussing theoretical implications for our understanding of personal experience and self-generated narrative. We also discuss other aspects of the present data that may be useful for investigating these thought processes in the future, including document-level features, typing dynamics, and individual difference measures.

This article explores how boat dwellers on the inland waterways of England and Wales – 'Boaters' – experience water and sanitation services. Boating populations are not counted as customers of private water utilities, so they exist within the 'dwelling paradox' and are positioned at greater risk of water and sanitation insecurity. Interviews and auto-ethnography document a myriad of ways in which participants use these resources on different vessels and waterways. The Capability Approach emerges as an apt framework for representing nuanced journeys from water and sanitation access to perceived quality of life. Findings suggest that equitable services can be defined as those which enable Boaters to live in ways they value. This entails reckoning with diverse – and potentially divergent – definitions of a 'good life', supported by the personal freedoms to achieve it. We argue this research makes a strong case for centring lived experiences in service design, particularly in instances of disagreement on the constitution of adequate service levels. Co-creating knowledge with people living in the dwelling paradox reveals complex relationships with authority and exclusion. We extend this theory, and the principles of equitable service delivery, to emphasise the situated desires, choices, and freedoms of the populations in question.

For the evaluation of the construction effect of engineering projects, this study combines the comprehensive evaluation index system and fuzzy mathematical methods, and improves the calculation process of the fuzzy matrix. A fuzzy mathematical method for the evaluation of river comprehensive improvement project is proposed. The results indicate that the comprehensive evaluation of river improvement benefits needs to start from four directions: engineering benefits, ecological benefits, economic benefits, and social benefits, with target layer weights of 0.2904, 0.4755, 0.0586, and 0.1755, respectively. The expert evaluation results indicate that most evaluation indicators of the project have a rating value greater than 5 points, and some indicators have a rating value of 8 points or above. This indicates that the evaluation samples for comprehensive river improvement in the research area perform well in most indicators and achieve good improvement results. The comprehensive evaluation index belongs to the second category of fuzzy values, and the effect of the river comprehensive improvement project is relatively ideal, which is consistent with the actual evaluation. The results indicate that this method converts qualitative indicators into quantitative indicators, making the evaluation results more comparable and quantifiable, which helps to promote the effective implementation of river regulation work.

Existing in situ global sediment monitoring limits our potential to answer regional and continental scale sediment transport questions. Remote sensing of rivers has an established history addressing these spatial and temporal data gaps but suffers from resolution and overpass timing tradeoffs. Satellite spatiotemporal data fusion can help alleviate these tradeoffs by “teaching” a coarse resolution sensor what it would have seen if it were a fine resolution satellite. In this study, we fuse Landsat/Sentinel-2 with MODIS to produce 30 m spatial data with Landsat bands and MODIS repeat frequency. We then create a database of 1.8M large river sediment concentrations derived from fused and nonfused images made over 1253 Continental United States sites, as validated with over 25 000 in situ measurements across these same sites. Combining fused and original images using a globally scalable workflow more than doubles training and prediction image data density with marginal loss in overall performance (combined model relative error 36% versus 33% landsat versus 39% fusion) and no loss in stability. Furthermore, we test our global model's ability to generate meaningful time series for individual large and small rivers included in and exogenous to the training data. Results indicate that global model skill holds when applied at a site, even out of sample, which paves the way for future sediment mapping in the MODIS era and shows the value of fusion for addressing hydrologic measurement challenges.