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Recently, the impact of climate change has led to an increase in the scale and frequency of extreme rainfall and flash floods. Due to this, the occurrence of floods and various river disasters has increased, necessitating the acquisition of technologies to prevent river disasters. Owing to the nature of rivers, areas with poor accessibility exist, and obtaining information over a wide area can be time-consuming. Artificial intelligence technology, which has the potential to overcome these limits, has not been broadly adopted for river detection. Therefore, the current study conducted a performance analysis of artificial intelligence for automatic river path setting via the YOLOv8 model, which is widely applied in various fields. Through the augmentation feature in the Roboflow platform, many river images were employed to train and analyze the river spatial information of each applied image. The overall results revealed that the models with augmentation performed better than the basic models without augmentation. In particular, the flip and crop and shear model showed the highest performance with a score of 0.058. When applied to rivers, the Wosucheon stream showed the highest average confidence across all models, with a value of 0.842. Additionally, the max confidence for each river was extracted, and it was found that models including crop exhibited higher reliability. The results show that the augmentation models better generalize new data and can improve performance in real-world environments. Additionally, the RivDet artificial intelligence model for automatic river path configuration developed in the current study is expected to solve various problems, such as automatic flow rate estimation for river disaster prevention, setting early flood warnings, and calculating the range of flood inundation damage. [ABSTRACT FROM AUTHOR]

The condition of the aquatic environment, particularly in protected areas of high ecological value such as the Narew River, requires detailed monitoring to identify and minimise the impact of anthropogenic factors on the ecosystem. This study focused on the content of heavy metals in bottom sediments and macrophytes of the Narew River, emphasising the influence of human activities and natural factors on this ecologically valuable ecosystem. Pb, Cr, Zn, Cd, Fe, and Mn concentrations were analysed in sediment samples, and ten macrophyte species were collected at 11 sampling points along the river. A geochemical index (Igeo) and multivariate statistical analyses were employed to identify sources of contamination. The digested samples (sediments and plants) were analysed for Pb, Cr, Cu, Zn, Ni, Cd, Fe, and Mn using flame atomic absorption spectrometry (AAS) on an ICE 3500 Thermo Scientific spectrometer, with a measurement error below 5%, validated against certified reference materials. The study results indicated that most metals, including Ni, Cr, Co, Fe, and Mn, predominantly originate from natural geological processes. In contrast, Zn, Cd, Cu, and Pb were identified as being enriched due to anthropogenic activities. An analysis of macrophytes revealed varied patterns of metal accumulation, which correspond to the bioavailability of metals and their environmental concentrations. Comprehensive statistical analyses provided insights into the predominant sources of metal contamination, closely associated with industrial emissions, agricultural runoff, and transportation activities. The integration of sediment and macrophyte monitoring allowed for a thorough evaluation of the Narew River ecosystem, facilitating the identification of key pollution sources. These findings highlight the critical need for measures to mitigate anthropogenic contributions of heavy metals—particularly from industrial, agricultural, and transportation sectors—to safeguard the Narew River's unique ecological and natural heritage. [ABSTRACT FROM AUTHOR]

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There is concern over potential toxic elements (PTEs) impacting river ecosystems due to human and industrial activities. The river's water, sediment, and aquatic life are all severely affected by the release of chemical and urban waste. PTE concentrations in sediment, water, and aquatic species from river ecosystems are reported in this review. Among the PTEs, chromium (Cr), cadmium (Cd), lead (Pb), and nickel (Ni) revealed high pollution levels in water and aquatic species (fish and shellfish) at many rivers. The Karnaphuli, Ganga, and Lee rivers have high levels of Pb and Cd contamination, while the Buriganga and Korotoa rivers' water had notable Ni contamination. A number of rivers with PTEs showed ecological risk as a consequence of the sediment's potential ecological risk (PER), the pollutant load index (PLI), and the geoaccumulation index (Igeo). A comprehensive study suggests elevated PLI values in river sediments, indicating significant pollution levels, particularly in the Buriganga River sediment, marked by high Igeo values. The PER of the Shitalakshya and Buriganga rivers was marked as very high risk, with an Eir > 320, while the Dhaleshwari and Khiru rivers showed 'high risk', with 160 = Eir < 320. It was found that fish and shellfish from the Buriganga, Turag, and Swat rivers have a high concentration of Cr. PTE pollution across several river sites could pose health toxicity risks to humans through the consumption of aquatic species. The CR value shows the carcinogenic risk to human health from eating fish and shellfish, whereas an HI value > 1 suggests no carcinogenic risk. The occurrence of other PTEs, including manganese (Mn), arsenic (As), and nickel (Ni), significantly increases the ecological risk and concerns to aquatic life and human health. This study emphasises the importance of PTE toxicity risk and continuous monitoring for the sustainability of river ecosystems. [ABSTRACT FROM AUTHOR]

Throughout the world, river basins are directly or indirectly affected by human activities, reducing local and global biodiversity and preventing the ecosystem from properly functioning. Our research focused on the Irpin River basin (Ukraine), whose water bodies have experienced various impacts due to human activities, including the unexpected extremes caused by military operations in the catchment area: long-term flooding, disturbance of free flow, significant water level fluctuations, etc. The study hypothesized that the primary factors determining the structural and spatial distribution of quantitative indicators of microalgae and aquatic macrophytes are the result of various hydromorphological changes, that lead to changes in the physical and chemical parameters of the aquatic environment. Very high values of chlorophyll a in the water column (59–106 µg · L−1), an increase in the abundance (number of cells) and biomass of algae (due to the predominance of certain groups in the transformed sections), as well as saprobic index were recorded in the sections of the Irpin River basin that underwent significant hydromorphological changes. Our results revealed a strong correlation between phytoplanktonic (in the water column) chlorophyll a levels and water temperature (r = 0.76, p < 0.001), as well as organic phosphorus and polyphosphate concentrations (r = 0.61, p < 0.01). ANOVA and Monte Carlo permutation tests in a Canonical Correspondence Analysis (CCA) showed that the abundance of different divisions of phytoplankton and phytobenthos were significantly and similarly related to several environmental variables. We observed a positive correlation between the number of cyanobacteria and the concentration of ammonium nitrogen, nitrites, and phosphorus compounds. An increase in dissolved organic matter in the water can explain the increase in the biomass of Dinoflagellata and Euglenophyta. Species richness and the cover values of the macrophytes also clearly reflected changes in vegetation activity in sections of the Irpin River caused by hydromorphological changes. The results indicated that long-term flooding had the most negative impact on macrophyte communities. At some sites, the impact was so severe that the number of macrophyte species was very low. The total number of macrophyte species showed a significant negative correlation with total suspended solids (r = −0.51, p < 0.05) and phytoplankton chlorophyll a concentration (r = −0.73, p < 0.001). Our results provide a scientific basis for predicting changes in riverine microalgal and aquatic macrophyte communities due to extreme hydrological events. [ABSTRACT FROM AUTHOR]

Waterfalls are a widespread element of the hydrographic network of Karelia and one of its "calling cards." The abundance of waterfalls is explained by the specifics of geological structure and geological history of the territory. The concentration of waterfalls is observed in the areas of tectonic-denudation topography. The most of waterfalls are located on small rivers and are characterized by relatively low heights and water discharge. The hydraulic engineering works led to the transformation of the hydrographical network and destruction of some waterfalls. Currently, many Karelian waterfalls play an important part in the tourism industry as places of recreation, sightseeing, and white-water tourism. [ABSTRACT FROM AUTHOR]

Microplastics are emerging pollutants that cause health problems for aquatic organisms. Fish is one of the important organisms because of its consumption by humankind. The present study examines the abundance and prevalence of microplastics in freshwater fish species through a systematic review study while considering five important factors, i.e. water resources, habitat, feeding behavior, Fulton's condition factor, and microplastic characteristics. A comprehensive meta-analysis was undertaken to evaluate relevant publications in terms of microplastic abundance. Articles published up to July 30, 2022 were found through Global search engines including, Web of Science, Scopus, and PubMed. In total, 786 articles were found that 53 and 42 articles were used for qualitative review and meta-analysis, respectively. This was carried out by a random-effects model with high heterogeneity (I2 = 99.76%). According to the data, the highest attention in microplastic research in body part and water sources are related to gastrointestinal tract (n = 259 (~ 80%)) and rivers (n = 189 (~ 58%)), respectively. According to the results, the average microplastic prevalence range was 5 -100%, and microplastic abundance was within the 0.04–204 items range per individual. The difference between microplastic prevalence and abundance for the key factors for parametric and nonparametric data were analyzed using Analysis of variance (ANOVA) and the Kruskal-Wallis test, respectively. According to the Baujat plot, two studies (ID: 27 and 25) revealed the minimal influence of microplastics abundance. Conclusively, the average microplastics abundance according to the pooled data, varied between 2.23 and 2.48, with a mean of 2.35 items per individual in the studies overall. It is concluded that the amount of ingested microplastics by fish is related only to physiology (height, weight, and body structure) but not feeding behavior, habitat, and surrounding water. [ABSTRACT FROM AUTHOR]

Water quality is crucial for the ecological health of rivers. However, assessing environmental stressors in large river basins has been challenging due to limited biodiversity monitoring tools. Combining environmental DNA and water quality monitoring presents new possibilities for evaluating the impact of dissolved organic matter (DOM) on fish diversity. Case studies from the Jinshui River, Futou Lake, and Gan River in the Jinshui River Basin demonstrated that eDNA biomonitoring reached 84.62% OTU asymptote (176 OTUs) and 91.06% species asymptote (49 species). The Gan River had 1.21 and 1.26 times more fish OTUs than Futou Lake and the Jinshui River, with 20 overlapping species among the areas. We identified typical excitation-emission matrix (EEM) components of DOM and three PARAFAC fluorescent components: C1 (microbial humic-like), C2 (terrestrial humic-like), and C3 (tryptophan-like). Sequence diversity was positively correlated with EC, TDS, pH, NH3-N, DO, CODMn, biological index (BIX), and freshness index (β/α). Taxonomic diversity positively correlated with spectral slope ratio (SR) and C3. Functional diversity positively correlated with SR but negatively correlated with humification index (HIX). The combined eDNA and DOM monitoring approach shows promise for future assessments of fish biodiversity in river basin environments. [ABSTRACT FROM AUTHOR]

It is reported that the magnitudes of flood events in riverine systems have been increasing due to global climate change. Because flood events could displace fish species downstream and/or increase the mortality of fish, it is important to know how the increased floods can affect fish in river networks. In this study, we focused a hatchery-raised amphidromous fish, Ayu Plecoglossus altivelis altivelis in a mainstem-tributary network in Japan and examined the relative fish abundance changes before and after the recordable massive flood using the environmental DNA (eDNA) analysis. We also examined the spatiotemporal patterns of the Ayu eDNA concentrations and the relationships with tributary discharge, width, and depth to examine if the relative abundance changes could be related to tributary size. Our results indicated that Ayu tended to inhabit large, deep tributaries more than small, shallow tributaries even after the flood event. Further, the eDNA concentrations of Ayu have decreased in most study sites after the flood; however, the eDNA concentrations in certain tributaries with lower tributary size have increased during the study period. These results suggest that (1) the habitat conditions could be important for the maintenance of Ayu populations before and after flood events, (2) increase in flood magnitude along climate changes could have impacts on Ayu populations, and (3) not only large tributary, but also small tributaries could be important habitats for the target species to avoid flood disturbances. [ABSTRACT FROM AUTHOR]

Predicting land-use and land-management effects on stream and river biota is an important aspect of land-water management, yet there are no collations of what methods are available to carry out those assessments nor guidance on which methods to use. This paper summarises a range of methods with examples of their applications, comments on their strengths and weaknesses, evaluates them against a set of criteria, and provides guidance on method selection. Assessment methods include empirical statistical and mechanistic models, Bayesian networks, likelihood–consequence risk assessments, scoring methods, and hybrid methods, some of which can be informed by expert elicitation. An evaluation matrix for methods indicated that no single method is ideal, and selection of methods needs to carefully consider factors such as the physico-chemical stressor or biotic impact of interest, the intended stakeholders, and the scales of assessment. One emergent principle is the separation of relationships between land use and stressors from assessments of stressors and biota, for which alternative methods could be used. A tiered approach is recommended, whereby simple methods with low resource and time requirements are applied first, followed by more sophisticated methods for selected aspects if needed. There is a need for more ready-made methods at the screening level, as well as development of new methods to address remaining gaps such as multiple stressors. [ABSTRACT FROM AUTHOR]

Aim: To determine which riverine invertebrate traits respond consistently to anthropogenic impacts across multiple biogeographic regions. Location: Europe. Time Period: 1981–2021. Major Taxa Studied: Riverine invertebrates. Methods: We compiled a database of riverine invertebrate community time series for 673 sites across six European countries spanning six freshwater ecoregions. We compared trait responses to anthropogenic impacts (quantified as changes in 'ecological quality') among regions for seven 'ecological' traits, which reflect habitat preferences, and nine 'biological' traits (e.g., morphology or life history), which represent taxon‐specific attributes that can influence ecosystem processes. Results: Four ecological traits (current, microhabitat, salinity and trophic preferences) and one biological trait (dispersal mode) responded consistently across regions. These responses were primarily driven by spatial differences among poorer to better quality sites. Responses to temporal changes in quality were comparable but less pronounced. Main Conclusions: Consistent responses to anthropogenic impacts across multiple ecological traits indicate these traits may improve broader scale measurements, comparisons and predictions of community responses. However, we could not use ecological traits to identify the actions of specific stressors because multiple traits always responded as a group. Inconsistent responses across almost all biological traits indicated that these traits may be less predictive of impacts across regions. Predictions of how biological traits, and associated ecosystem processes, respond to anthropogenic impacts may be most effective at regional scales where responses are more consistent. [ABSTRACT FROM AUTHOR]

Riverine fungi have the capacity for both pathogenicity, pertinent for countries with elevated immunosuppressed individuals, and bioremediation potential. The purpose was (i) to screen for the presence of clinically relevant riverine fungi and associations with anthropogenic influence, and (ii) the acclimatisation of environmental communities toward potential bioremediation application. Communities were harvested from polluted rivers in Stellenbosch, South Africa, and mycobiomes characterised by high-throughput amplicon sequencing. The remainder of the biomass was inoculated into continuous bioreactors with filtered river water or sterile minimal medium. Seven weeks later, the mycobiomes were re-sequenced. At least nine clinically relevant species were detected, including agents of mycoses belonging to the genus Candida. The occurrence of genera that harbour opportunisticstrains was significantly higher (P = 0.04) at more polluted sites. Moreover, positive correlations occured between some genera and pollution indices, demonstrating the potential of fungi for addition to water quality indicators. Despite biomass increase, almost all pathogens were undetectable after seven weeks, demonstrating less resilience in conditions mimicking rivers. Thus, when screening riverine biomes for bioremediation potential, ambient reactors select against human pathogens. This indicates a transient introduction of allochthonous opportunistic species into rivers due to insufficient sanitation, and the potential of bioremediation strategies that selects for environmental rather than pathogenic traits. [ABSTRACT FROM AUTHOR]

Plastic is a growing global environmental problem. While much of the focus of anthropogenic microparticles has focused on microplastics and their occurrence in marine systems, anthropogenic microparticles are found in freshwater systems. The Charles River is a highly impacted and historically important river within Massachusetts and runs for 80 miles within the state of MA through a variety of land uses. Microparticle concentrations were found to vary along the length of the river and ranged in concentrations from 1–19 pieces/L, with generally higher concentrations downstream. Microfibers were the dominant (72%) type of microparticles found, and the majority (avg 76%) of microparticles were synthetic. The highest estimated flux of microparticles occurred in May, with an estimated flux of 2 billion microparticles per day via the Charles River into the Boston Harbor. The average annual concentration of microparticles was correlated with land use, with higher concentrations occurring in regions with higher impervious coverage and in areas designated as industrial or high-density residential. Polyester, polypropylene, and polyamides were the dominant plastic polymers. However, seasonal changes in the relative importance of each polymer, along with changes in the abundance and flux rates, indicate that there would be seasonal variability in the type of microparticles exported. Changes in composition occurred between stations and between the head and mouth of the river, suggesting particle retention due to either deposition, degradation, or biological consumption. [ABSTRACT FROM AUTHOR]

This study analyzes changes in the water temperature in the Pilica River (Poland), encompassing both historical data (1958–2023) and projections extending to the year 2100. We use multi-model ensembles (MMEs) with Bayesian Model Averaging (BMA) to integrate various Global Climate Model (GCM) datasets for current and projected climate data. Additionally, a Random Forest (RF) machine learning method is applied to project future water temperatures in the Pilica River. It has been demonstrated that over a period of more than sixty years, the average annual water temperature has increased by nearly 2 °C. Further changes are expected to continue in a similar direction with a gradual rise in this parameter, reaching a temperature increase of 3 °C by the end of the 21st century (SSP585). In the distant future, with average monthly water temperature changes at the Przedbórz station ranging from 0.27 °C to 0.87 °C·decade−1 and at the Białobrzegi station from 0.22 °C to 1.06 °C·decade−1. The results of these changes are concerning, especially considering the crucial role of water temperature in shaping seasonality and the dynamics of processes occurring within the river. In the context of the sustainability of the river itself, but also of the entire catchment area, strategies developed by relevant public administration bodies are needed to mitigate the impacts of global warming observed in the thermal regime of the Pilica River. [ABSTRACT FROM AUTHOR]

Water pollution presents one of the biggest challenges in the world today, as the degradation of water quality of rivers in many instances is increasing so fast and poses a big danger to all forms of life, eventually causing many aquatic species and other species that depend on them to be endangered. Hence, with the development of Internet of Things (IoT) and Wireless Sensor Networks (WSNs), there arises a need to monitor river waters for a timely response in protecting the rivers, which is the aim of this paper. With respect to this project, we searched a little bit for some existing IoT technologies and other related work. In this paper, we propose a practical low-cost solution based on Long Range (LoRa) technology to obtain real-time observations of, with certain sensors, such water parameters as temperature, pH, conductivity and turbidity. Data gathered at a sensor node are transmitted via LoRa modulation to a gateway for processing and local storage on a Message Queuing Telemetry Transport (MQTT) server, visualization on a Node-RED interface, or transmission to the cloud. The prototype system created is employed in the actual field and demonstrates that the water quality monitoring in the river can be carried out effectively within a small scale of the area of roughly 20 km2 depending on the location of the study site. [ABSTRACT FROM AUTHOR]

Bristlenose catfish, specifically Ancistrus chagresi Eigenmann & Eigenmann, 1889 and Ancistrus sp. have been found in the Ciliwung watershed, Indonesia. These two species are alien fishes from Central and South America. Out of the six specimens, five Ancistrus chagresi had a standard length of 35.76-71.67 mm, while one Ancistrus sp. measured 73.43 mm. The presence of these two species in Indonesian waters could lead to them becoming invasive and consequently impacting native species. It is imperative to handle both Ancistrus species carefully to prevent their population from growing uncontrollably. [ABSTRACT FROM AUTHOR]

Abstract Water quality management is a critical aspect of environmental sustainability, particularly in arid and semi-arid regions such as Iran where water scarcity is compounded by quality degradation. This study delves into the causal relationships influencing water quality, focusing on Total Dissolved Solids (TDS) as a primary indicator in the Karkheh River, southwest Iran. Utilizing a comprehensive dataset spanning 50 years (1968–2018), this research integrates Machine Learning (ML) techniques to examine correlations and infer causality among multiple parameters, including flow rate (Q), Sodium (Na+), Magnesium (Mg2+), Calcium (Ca2+), Chloride (Cl−), Sulfate (SO4 2−), Bicarbonates (HCO3 −), and pH. For modeling the causation, the “Back door linear regression” approach has been considered which establishes a stable and interpretable framework in causal inference by focusing on clear assumptions. Predictive modeling was used to show the difference between correlation and causation along with interpretability modeling to make the predictive model transparent. Predictive modeling does not report the causality among the variables as it showed Mg is not contributing to the target (TDS) while the findings reveal that TDS is predominantly positive influenced by Mg, Na, Cl, Ca and SO4, with HCO3 and pH exerting negative (inverse) effects. Unlike correlations, causal relationships demonstrate directional and often unequal influences, highlighting Mg as a critical driver of TDS levels. This novel application of ML-based causal inference in water quality research provides a cost-effective and time-efficient alternative to traditional experimental methods. The results underscore the potential of ML-driven causal analysis to guide water resource management and policy-making. By identifying the key drivers of TDS, this study proposes targeted interventions to mitigate water quality deterioration. Moreover, the insights gained lay the foundation for developing early warning systems, ensuring proactive and sustainable water quality management in similar hydrological contexts.

This paper presents an overview of the Danube municipalities on the Bulgarian coast, with a particular focus on their spatial and socio-economic characteristics as territorial units. The paper outlines the structural postulates that highlight the importance of the Danube coast for the regional development of the Danube region and the development of the Bulgarian geographical space. The paper goes on to present a characterization of the Danube region in a more general context as a part of the pan-European space, together with an outline of the development of socio-geographical processes and phenomena. In practice, the region presents many challenges for forming regional development policies and interest in the area in terms of tourism and investment. The paper presents relevant conclusions and recommendations for developing the Bulgarian municipalities along the Danube.

Groundwater is considered an important source of water supply in Iraq, but the poor quality of water makes it unsuitable for drinking purposes. To enhance the groundwater quality, River Bank Filtration (RBF) method was investigated. It is a natural process in which wells along a riverbank are pumped, causing some of the river water to flow toward these wells. With this technique, water coming from the river is filtrated by soil deposits and then mixed with groundwater, improving its quality. The purpose of this study is to evaluate the implementation of the RBF technique to improve the poor quality of groundwater and get potable water. A study area was selected in Al Hindiyah District within Kerbala City, Iraq. Four wells (W1, W2, W3, and W4) with different distances from the Euphrates River bank (450 m, 720 m, 800 m, and 1950 m), respectively, were selected to examine the groundwater quality. The results were then compared to those for the Euphrates River. In addition, two boreholes (B.H.1 and B.H.2) of about 15 m depth were drilled near the riverbank to assess the soil properties of the studied area. The results showed that the groundwater quality at a depth more than 12 m enhanced as the well’s distance from the river bank decreased and got closer to the river. It was found that the water quality at pumping wells (W1, W2, and W3) is slightly polluted, which makes this area more suitable for groundwater abstraction to provide the best water quality. The poorest water quality was for W4 at 1950 m from the riverbank, which indicates that at this distance the river bank filtration process is eliminated.

The aim of this study, conducted in accordance with both European Union and national legislation, was to evaluate the physicochemical conditions of the Rega River in northern Poland, where efforts are underway to restore its watershed for migratory fish. From 2018 to 2022, water temperature, dissolved oxygen (DO), pH, total suspended solids (TSS), conductivity, alkalinity, total hardness (TH), biochemical oxygen demand (BOD5), chemical oxygen demand (CODCr), nitrite nitrogen (NO2-N), ammonium nitrogen (NH4-N), and total phosphorus (TP) were measured at nine monitoring sites. The results showed that TSS and nitrite nitrogen (NO2-N) were the main factors threatening the suitability of the Rega River as a habitat for salmonid fishes. Additionally, maximum water temperatures occasionally exceeded the tolerance limits for these fishes. Seasonal variations in nitrogen and phosphorus forms, and the dependency of nitrogen forms on DO, indicated disruptions in natural biochemical processes due to surface runoff pollutants from the watershed. This includes fertilizer runoff from agricultural fields and municipal pollution from the towns through which the river flows. The findings underscore the need for continuous monitoring of Rega River waters to safeguard the habitat conditions required by environmentally sensitive fish species.

Freshwater salinization is receiving increasing global attention due to its profound influence on nitrogen cycling in aquatic ecosystems and the accessibility of water resources. However, a comprehensive understanding of the changes in river salinization and the impacts of salinity on nitrogen cycling in arid and semi-arid regions of China is currently lacking. A meta-analysis was first conducted based on previous investigations and found an intensification in river salinization that altered hydrochemical characteristics. To further analyze the impact of salinity on nitrogen metabolism processes, we evaluated rivers with long-term salinity gradients based on in situ observations. The genes and enzymes that were inhibited generally by salinity, especially those involved in nitrogen fixation and nitrification, showed low abundances in three salinity levels. The abundance of genes and enzymes with denitrification and dissimilatory nitrate reduction to ammonium functions still maintained a high proportion, especially for denitrification genes/enzymes that were enriched under medium salinity. Denitrifying bacteria exhibited various relationships with salinity, while dissimilatory nitrate reduction to ammonium bacterium (such as Hydrogenophaga and Curvibacter carrying nirB) were more inhibited by salinity, indicating that diverse denitrifying bacteria could be used to regulate nitrogen concentration. Most genera exhibited symbiotic and mutual relationships, and the highest proportion of significant positive correlations of abundant genera was found under medium salinity. This study emphasizes the role of river salinity on environment characteristics and nitrogen transformation rules, and our results are useful for improving the availability of river water resources in arid and semi-arid regions.

Abstract The increasing pollution of river systems poses a significant challenge to water quality management and public health. This study was conducted to evaluate the water quality of the Gomati River in India, focusing on the impact of anthropogenic activities on pollution levels across different seasons. The primary objective was to develop a comprehensive assessment model using an effective weighted fuzzy soft expert system (WFSES) to derive a weighted water pollution score (WWP-score) for rating water pollution levels based on various water quality parameters. To achieve this, we employed a fuzzy soft set (FSS) methodology integrated with a weighted fuzzy soft set (WFSS) model to analyze water quality indices at six sampling stations along the Gomati River, the largest river in Tripura, India. Originating from the Raima and Sarma streams, the river flows westward through key regions, providing 249.39 million cubic meters of water annually, essential for drinking, agriculture, fishing, and transportation. The study utilized crisp data summaries of key water quality parameters, including pH, total dissolved solids, total suspended solids, electrical conductivity, biochemical oxygen demand, dissolved oxygen, total hardness, chloride, total alkalinity, and total coliform, across the pre-monsoon, monsoon, and post-monsoon seasons from May 2022 to April 2023, guided by the distribution of waste discharge points. Fuzzy membership functions were defined for these parameters, and the root mean square (RMSQR) operation was used to combine multiple FSSs. The results revealed that the WWP-scores, a measure of water quality, ranged from 0.744 to 0.872 across the sampling stations, with Srimantapur exhibiting the highest level of pollution and Udaipur showing comparatively better quality. These scores indicate that water quality at all sites falls into the poor category, with Srimantapur experiencing the most severe contamination due to high levels of coliform bacteria and organic pollutants. The analysis highlights the impact of domestic wastewater and agricultural runoff on the river's health. This research offers a novel application of FSS and WFSS theory in environmental management, providing a robust framework for evaluating and ranking water quality across multiple parameters. The findings are valuable to the scientific community as they offer detailed insights into the pollution dynamics of the Gomati River and propose a methodological approach for assessing water quality in other river systems facing similar challenges. The study's results underscore the need for targeted pollution control measures and continuous monitoring to safeguard water resources and public health.

The bioaccumulation of potentially toxic elements (PTEs) in aquatic plants is critical in assessing the quality of aquatic environments and the risks associated with anthropogenic activities. This research involved using Phragmites australis as a bioindicator in a comprehensive assessment of the spatial variation in pollution within the Bug River catchment, employing advanced statistical methods to identify pollution sources. The study aimed to investigate the bioaccumulation of PTEs in different parts of the P. australis plant and to evaluate their suitability as bioindicators of contamination. Plant samples were collected from 32 locations in the Bug River catchment, and the concentrations of metals such as Cd, Pb, Cr, Ni, Zn, Cu, Fe, and Mn were determined by atomic absorption spectrometry. The results indicated that PTE accumulation was highest in the roots, underscoring their crucial role in monitoring metal concentrations. Metal concentrations differed based on land use within the catchment area, with the highest levels observed in urbanized regions, highlighting the significant impact of human activities like wastewater discharge and transport emissions. The highest concentrations were observed for Fe, Mn, and Zn, while Cd concentrations were notably elevated in agricultural areas. The analyses confirmed that P. australis serves as an effective bioindicator of heavy metal contamination and can be employed in long-term biomonitoring programs. [ABSTRACT FROM AUTHOR]

This study aimed to assess the spatial distribution, diversity, and community composition of gastropods in the anthropogenically altered Kana Damodar River (Kaushiki), West Bengal, India. Monthly collections of gastropods were conducted at five sampling sites (KD1-KD5) during the 2019-20 and 2021-22 sampling periods using various sampling methods. Three diversity indices were computed: dominance index, Shannon-Weiner index, and Margalef's richness index. Hierarchical cluster analysis using the Bray-Curtis similarity matrix and one-way analysis of similarities (ANOSIM) were employed to evaluate the spatial organization and dissimilarity of gastropod assemblages across the sampling sites. Eleven (11) gastropod species, distributed across eight (8) families, were recorded from five sampling stations. The study revealed significant spatial variability in species composition, with Filopaludina bengalensis and Radix rufescens being the most dominant species. The dominance index showed a prevalence of a few opportunistic species, with values ranging from 0.24 to 0.46. The Shannon-Weiner index (H') ranged from 0.55 to 1.98, indicating low species diversity across all stations, which suggests potential vulnerabilities in ecosystem stability of the studied river. Margalef's richness index showed notable variation in species richness, with values ranging from 0.79 to 1.55, suggesting reduced gastropod diversity in the studied river. Hierarchical cluster analysis and ANOSIM further underscored the spatial heterogeneity of gastropod communities across the studied river. The findings of this study highlight the urgent need for targeted conservation and site-specific management strategies to address the unique ecological challenges at each sampling station in the River Kana Damodar (Kaushiki). [ABSTRACT FROM AUTHOR]

This research was aimed to examine the habitat characteristics, growth patterns and condition factors of T. tambra in the Mamis River, Leuser Ecosystem Area, Aceh, Indonesia. This research was conducted on the Mamis River in three different river conditions from July to August 2023. The ecological parameters of T. tambra were conducted by observing the main, broodstock, spawning, and nursery ground habitats based on diversity of catch size at a location, water quality, aquatic substrate, aquatic vegetation, and water shade. The growth pattern parameter was also analysed to reveal the condition of T. tambra. The T. tambra habitat in the Mamis River includes broodstock and spawning habitat with the criteria from small to large rocks overgrown with Bryophytes, gravel and sand substrates, clear water color, slow to swift water currents, and river environment. Most of it is primary forest. In the main habitat, there is dominant riparian vegetation in the form of forest timber trees such as Pometia pinnata, Ficus fistulosa, Hydnocarpus castanea, and Aglaia tomentosa. The habitat for the juvenile is in the form of rocks, gravel substrate, clear water color, and fast water currents. In the nursery habitat, the dominant riparian vegetation is Balakata baccata. Based on the results of the water quality analysis at the three stations show that temperature, pH, DO, currents, BOD, COD are significantly different, but brightness levels are not significantly different. The analysis of the length-weight relationship shows that the condition of the fish is stable, and sufficient food is available. [ABSTRACT FROM AUTHOR]

Modeling of riverine dissolved organic carbon (DOC) dynamics is of great importance for the global carbon budget. Impoundment interception changes the travel time of water and DOC from upslope contributing areas, exerting substantial influence on riverine DOC dynamics in the catchments with many impoundments. However, the impact of impoundment interception representation on riverine DOC modeling has not been evaluated so far. This study investigated to what extent impoundment interception representation affects DOC simulations using a newly developed catchment‐scale DOC model, which can represent the upslope contributing areas of impoundments and the impoundment interception process. The results showed that streamflow and DOC load simulation were well simulated regardless of whether impoundment interception was represented, but the simulation of DOC concentrations was satisfiable only when impoundment interception was taken into account. The simulation without impoundment interception produced unrealistic fluctuation of DOC concentration due to the direct mixing of DOC from different sources with contrasting concentration gradients. These results underscored the significance of employing an appropriate model structure for riverine DOC simulation. It is strongly recommended that DOC concentration be utilized for model evaluation in order to attain robust simulation outcomes. Moreover, the newly developed model in this study keeps a balance between the completeness of process presentation and model complexity, occupying a unique "ecological niche" among catchment‐scale riverine DOC models. Key Points: Evaluate the impact of impoundment interception on riverine DOC simulation for the first timeConsidering impoundment interception improves both the accuracy and temporal pattern of simulated DOC concentrationBoth DOC concentration and load are necessary for model evaluation [ABSTRACT FROM AUTHOR]

Legal personhood has been recognized for several ecosystems worldwide, garnering significant attention from the scholarly community. This attention translated with the mobilization of approaches anchored into legal, institutional, or ethnographic perspectives. On-going calls for the recognition of Rhone River's legal personhood provides us the opportunity to analyze on-going processes in a transboundary river located in the middle of Europe. This paper focuses on how such a concept gets promoted and intends to make its way on the political agenda. Specifically, we examine two current promoters of the legal personhood of the Rhone River: the International Commission for the Protection of Lake Geneva (CIPEL) and ID-Eau. We identify five key lessons: (1) the request for recognition of legal personhood derives from actors' willingness to change current governance practices and to shift the productivist paradigm towards more decentralized and inclusive governance system; (2) legal personhood is presented as a solution to problems that have not yet been clearly framed nor identified, opening up thinking on how such concept may be instrumentalized; (3) the discussion remains limited to a small number of experts; (4) the legitimacy of this debate requires scrutiny; (5) the legal personhood concept should be reinterpreted to fit within Western ontologies. [ABSTRACT FROM AUTHOR]

River sediment supply (Qs) and longshore sediment transport (LST) are recognized as two paramount controls on river delta morphodynamics and stratigraphy. We employed the Delft3D model to simulate the evolution of deltas from fluvial to wave‐dominated conditions, revealing the interplay between river‐ and wave‐driven sediment quantities. Wave‐influenced deltas may show alternating accumulation and retreat patterns driven by avulsions and wave‐induced sediment diffusion, posing coastal management challenges. Deltas with higher wave energy evolve under a fine balance between river supply and intense wave‐mediated sediment redistribution and are highly vulnerable under conditions of sediment reduction. Reducing Qs by ∼40%–70%, common in modern dammed rivers, can rapidly shift bypass from ∼0 to 1 (no bypass to complete bypass). This leads to accelerated diffusion and potential sediment loss in modern deltas. The study highlights the importance of accurately computing sediment quantities in real‐world deltas for improved management, especially under increasing anthropogenic and climatic pressures. Plain Language Summary: Ocean waves, like proficient sculptors, shape the meeting points of rivers and seas—where deltas are created. Under the power of ocean waves, the sediments transported by rivers are organized into distinct patterns. Using an advanced computer model, our research unveils how this interplay affects the physical form of these deltas and their functioning. In certain conditions, the sediment carried by waves can jump over the river mouth and move further along the coastline, contributing to stretching the delta and inducing erosion. Currently, river sediments are getting blocked behind river dams, depriving deltas of their sediment nourishment. As sediment supply decreases, powerful waves at the sea erode deltas more easily, endangering ecosystems, human communities and infrastructure. Because deltas are facing challenges from climate change and increased human activities, informed and innovative management strategies based on better knowledge of natural processes are needed to preserve these valuable coastal regions. Key Points: Deltas transition from avulsion‐dominated with localized depocenters to more diffuse and alongshore‐deflected wave‐dominated depocentersBypass increases and trapping decreases abruptly when longshore transport (LST) at the river mouth equals river sediment transport (Qs)LST under large‐scale blocking due to mouth bar and shoreface adjustment feeds wave‐dominated updrift beach ridge plains (strandplains) [ABSTRACT FROM AUTHOR]