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Rivers are environmental features that react strongly to changes in their beds. Tectonics is the most important factor affecting the morphology of rivers, causing significant changes in river systems. In this study, we investigated the effect of tectonic activity on river systems in the eastern slopes of Mullah Daghi, southeast of Zanjan province. This area is drained by the Abhar River. We used the Digital Elevation Model (DEM), Geographic Information System (GIS), and Global Mapper 13 for our investigation. In the ArcGIS software environment, we used the DEM to prepare required maps, including geological maps and topography. We used the 1:250,000 Geological Map of Zanjan to create the fault map. To achieve our research objectives, we analyzed tectonic activity indicators such as mountain front sinuosity, basin shape, drainage density, longitudinal gradient of the river, river meanders, basin asymmetry, hypsometry integral, topographic symmetry of the basin, and width of the valley floor to the height. These indicators were combined to calculate the tectonic activity index (IAT). The results obtained through the IAT index indicate the activation of tectonic and neotectonic activities in the Ardejin and Abhar watersheds, and moderate activity in the Zareh Bash basin. These activities have different impacts on the river systems in the studied basins, such as river meanders in the Ardejin watershed basin, tilted watersheds in Abhar and Ardejin, and elongated basins in Zareh Bash. [ABSTRACT FROM AUTHOR]

The contamination of river systems by tailing dust remains a constraint to goat productivity in communal farming systems. A cross-sectional study was conducted to investigate how resource-limited households in subtropical regions assessed the effects of tailing dust contamination in drinking water on the health status of goats. In a study conducted in the Ba-Phalaborwa Local Municipality, 200 households from two villages were randomly selected and interviewed using a questionnaire. Forty-eight percent (n = 96) of the households were located in contaminated areas, while 52% (n = 104) were from uncontaminated areas. The study found that poor water quality, caused by tailing dust contamination, as well as a high incidence of diseases, were key factors affecting goat productivity. Water contamination was most severe during the hot and cool dry seasons. It was also noted that goats rely on freshwater as their primary source of supplemental water during dry seasons. Urine colour, oedema of the eyelids, and kid survival were indicators for assessing the health status of goats. Nominal binary logistic regression revealed that water contamination was 2.96 more likely to be reported by youth compared to elderly members. Farmers who received informal education were 37 times more likely to report contamination than those who received formal education. High kid mortality as a health status indicator was 50 times less likely to be reported in uncontaminated areas. Intervention strategies for reducing the adverse health effects of tailing dust in contaminated areas should focus primarily on the health of goats during dry seasons. [ABSTRACT FROM AUTHOR]

Understanding the relationship between sediment loading and its environmental implications in river systems is crucial for water resource management and environmental protection. This study explored the spatiotemporal characteristics of sediment loading and their environmental relationships in seven large rivers in China, aiming to quantify the contributions of various factors to changes in sediment transport. Monitoring data spanning twenty-one years (2002 to 2022) on sediments, hydrology, and the environment collected by sixty-five stations were analysed. The multivariate statistical techniques employed included Spearman’s correlation analysis, principal component analysis, and multivariate regression modeling. The results show that sediment transport in various river systems exhibited spatial heterogeneity, the maximum annual average sediment loadings (1.59 × 108 t/yr) occur in the lower reaches of the Yellow River, the middle reaches have the highest sediment concentration (41.54 kg/m3), followed by the downstream of the Yellow River (5.85 kg/m3). Sediment loading and runoff changes in the basins did not adhere universally to synchronous patterns. Eleven of the thirteen basins of these river systems showed upward trends in annual runoff volume, whereas nine basins showed downward trends in annual sediment loading. Runoff volume accounted for over 30 % explanatory of sediment loading variations in all seven large river systems, with the Yangtze, Huaihe, Qiantang, and Songhua rivers surpassing 60 % of the explanatory power. The Normalized Difference Vegetation Index of all watersheds showed an increasing trend, whereas the index of nine of the thirteen watersheds was correlated negatively with sediment transport. The influence of human activities on basin sediment transport was higher than that of natural resilience, whereas afforestation significantly reduced sediment in arid regions. This study provides insight into the temporal and spatial characteristics of sediment loadings and the driving effects of environmental factors, which has great significance for watershed environmental management.

Sensor networks are used in an increasing number and variety of application areas, like traffic control or river monitoring. Sensors in these networks measure parameters of interest defined by domain experts and send these measurements to a central location for storage, viewing and analysis. Temporal graph data models, whose nodes contain time-series data reported by the sensors, have been proposed to model and analyze these networks in order to take informed and timely decisions on their operation. Temporal paths are first-class citizens in this model and some classes of them have been identified in the literature. Queries aimed at finding these paths are denoted as (temporal) path queries. In spite of these efforts, many interesting problems remain open and, in this work, we aim at answering some of them. More concretely, we characterize the classes of temporal paths that can be defined in a sensor network in terms of the well-known Allen's temporal algebra. We also show that, out of the 8192 possible interval relations in this algebra, only 11 satisfy two desirable properties that we define: transitivity and robustness. We show how these properties and the paths that satisfy them are relevant in practice by means of a real-world use case consisting of an analysis of salinity that appears close to the Scheldt river in Flanders, Belgium, during high tides occurring in the North Sea. [ABSTRACT FROM AUTHOR]

Zinc (Zn) is an essential trace element widely present in rivers and plays a crucial role in ecosystems. Human activities have led to the extensive migration and dissemination of Zn in the environment. When the accumulation of Zn in rivers reaches excessive levels, it transforms into a potentially harmful contaminant. Consequently, tracing Zn's origin by its isotope ratios (δ66Zn) from natural and anthropogenic sources is essential for the management of and safeguarding against river pollution and comprehending Zn behavior in rivers as well. This review presents the advancements in Zn isotope research in river environments, including a summary of Zn isotope measurement, the distribution and controlling factors (mineral adsorption, precipitation, and biological effects) of Zn isotopes, and the applications of Zn isotopes in rivers. The median δ66Zn values for uncontaminated river water and suspended particulate matter (SPM) were 0.37‰ and 0.22‰, respectively, close to the bulk silicate Earth (BSE) value of 0.28 ± 0.05‰. With respect to the contaminated river, δ66Zn falls within −0.73‰ to 1.77‰, with it being heavily influenced by anthropogenic sources, such as the electroplating and metal processing industries. Apart from contamination identification, this review summarizes the river material exchange process and the δ66Zn values of rainwater (−0.2‰~0.38‰), groundwater (−0.13‰~1.4‰), lake water (−0.66‰~0.21‰), and seawater (−1.1‰~0.9‰), which facilitates a holistic understanding of the Zn cycle and isotope fractionation in the river system. In conclusion, Zn isotopes are an effective tool for tracing pollution sources and Zn migration processes, with enormous unexplored potential. Therefore, this review finally summarizes some challenges and future directions in current research on Zn isotopes. [ABSTRACT FROM AUTHOR]

This study investigated weathering and hydrobiogeochemical processes in a silicate dominated watershed (Svratka river) in the Czech Republic in comparison with nearby carbonate dominated catchments. Elemental and isotopic analysis of river waters, particulates and sediments provided a more holistic view of weathering contributions, anthropogenic contamination, biological activity and evasion or sinks of CO2 to the atmosphere. In water samples, we determined total alkalinity after Gran 1974, and cations and anions were determined with inductively coupled plasma–optical emission spectrometer and ion chromatograph. δ13CDIC in water samples was determined with isotope ratio mass spectrometer. pCO2 and saturation indexes of calcite and dolomite were calculated with PHREEQC speciation program. Evasion fluxes were calculated after Broecker, 1974. Isotopic composition of carbon and nitrogen in particulate matter and sediments were determined with isotope ratio mass spectrometer. Mineral composition of sediments was determined with XRD method and elements with XRF method. Further enrichment factors of elements were calculated. The Svratka river, which is the major tributary of the Dyje river, is dominated by Ca2+ > Na+ > Mg2+ > K+ and HCO3− (as total alkalinity). Partial pressure (pCO2) concentrations range from close to 0–572-fold of atmospheric pressure. Isotopic composition of carbon in dissolved inorganic carbon (δ13CDIC) value ranged from − 13.3 to − 8.0‰ reflecting degradation of organic matter and exchange with the atmosphere. Bicarbonate weathering intensity for the Svratka river at its mouth is 11.8 mol/(l⋅km2⋅s), more on par with silicate terrains and lower than nearby carbonate watersheds. Isotopic composition of carbon (δ13C) and isotopic composition of nitrogen (δ15N) values of river sediment reflect soil and temperate plant (C3 plant) values, while higher δ15N values could be attributed to application of organic fertilizers in lower reaches. The river sediments, which came from weathering of crystalline rocks, are dominated by silt size, geochemically less mature quartz, feldspar and muscovite particles. All the stream sediments examined revealed slightly increased amounts of Zn, Cu and Pb. However, using Al as the normalization element to calculate enrichment factors, Zn, Cu and Pb are only elevated downstream, related to industrial contamination. This study is important for local and global level since it deals with contribution of weathering rates and contribution of CO2 to the atmosphere in silicate watershed. [ABSTRACT FROM AUTHOR]

The desire to have a better grip of the history and to interpret the causes and nature of certain social phenomena is characteristic of humanity at all stages of development. Expansion of cognitive capabilities of historical research, the creation of new units in the mental lexicon allow us to increase the range of vision of history, to give the understanding of the past a holistic, more capacious understanding. Translation of history in the context of many sciences creates resources for the emergence of generally accepted attitudes into a different semantic dimension, filling them with more weighty argumentation. In the modern scientific space historical geography appears to be a promising territory, given a certain conditionality of the development of society at all stages of the existence influenced by the natural-geographical factor. In the early stages of human development the existence of people depended on the characteristics of nature to a much greater extent than today. Nevertheless, modern civilization, despite the scientific progress, has not managed to distance itself from the influence of nature and is still interconnected with it by many threads. This general situation is fully true for the Circassians, the borders of the territory, which were deliberately created by nature itself for the conservation of the population within its natural limits. In this regard, the subject of the research is the problem of the influence of the natural-geographical factor on the historical process of the Circassians. The object of the research is the peculiarities of the geography of the region, reflecting the degree of the role of the natural environment in the formation of the Adygh ethnos. The aim of the research is to analyze the nature of the interaction and conditionality of the Adygeyan history by the natural environment, rightfully recognized as one of the most ancient and unique cradles of the landscape map of our country. To achieve this goal tasks were set related to the analysis of the content, orientation and mediation of the progressive development of the Circassians by the peculiarities of the natural environment. In this research the understanding of the sought problem is based on the ideas of major philosophers, historians, sociologists, and cultural scientists. The research methodology is based on the principles of historicism and objectivity, which allows us to see new facets in understanding many phenomena of the Adyghe history, to give them a value characteristic

Flood flow forecasting is essential for mitigating damage in flood-prone areas all over the world. Advanced actions and methodology to optimize peak flow criteria can be adopted based on forecasted discharge information. This paper applied the models of the integrated wavelet, multilayer perceptron (MLP), time-delay neural network (TDNN), and gamma memory neural network (GMNN) to predict hourly river-level fluctuations, including storage rate change variable. Accordingly, the researchers initially used the discrete wavelet transform to decompose the water discharge time-series into low- and high-frequency components. After that, each component was separately predicted by using the MLP, TDNN, and GMNN models. The performance of the proposed models, namely wavelet–MLP, wavelet–TDNN, and wavelet–GMNN, was compared with that of single MLP, TDNN, and GMNN models. This analysis affirms that precision is better in the case of integrated models for forecasting river reach levels in the study region. Furthermore, multiple inputs–multiple outputs (MIMO) networks (MIMO-1 artificial neural network (ANN) and MIMO-2 ANN), along with multiple inputs–single output (MISO) ANN were employed for obtaining flow forecasts for several sections in a river basin. Model performances were also evaluated using the root mean squared error having less than 10% of the average mean value, with the coefficient of correlation being more than 0.91 and with the peak flow criteria showing the chances of flash floods being low to moderate with values not more than 0.15. HIGHLIGHTS The wavelet-based ANN model incorporating storage changes has been accounted for in river flow studies.; The study is unique while showcasing comparative analysis between different ANNs modeling.; Flood prediction using pre-processing technique wavelet along with the ANN seems the best model.; The flood damage mitigation is the need of the hour, which is the main aim for areas prone to heavy precipitation.; Results seem to be promising.;

Transportation networks are used in many application areas, like traffic control or river monitoring. For this purpose, sensors are placed in strategic points in the network and they send their data to a central location for storage, viewing and analysis. Recent work proposed graph databases to represent transportation networks, since these networks can change over time, a temporal graph data model is required to keep track of these changes. In this model, time-series data are represented as properties of nodes in the network, and nodes and edges are timestamped with their validity intervals. In this paper, we show that transportation networks can be represented and queried using temporal graph databases and temporal graph query languages. Many interesting situations can be captured by the temporal paths supported by this model. To achieve the above, we extend a recently introduced temporal graph data model and its high-level query language T-GQL to support time series in the nodes of the graph, redefine temporal paths and study and implement new kinds of paths, namely Flow paths and Backwards Flow paths. Further, we analyze a real-world case, using a portion of the Yser river in the Flanders' river system in Belgium, where some nodes are equipped with sensors while other ones are not. We model this river as a temporal graph, implement it using real data provided by the sensors, and discover interesting temporal paths based on the electric conductivity parameter, that can be used in a decision support environment, by experts for analyzing water quality across time. [ABSTRACT FROM AUTHOR]

Rivers are vital components of the biosphere and an excellent habitat for many of the Earth's organisms. The prime focus of this study is the Iloilo River located in the City of Iloilo, Panay Island, Philippines. It is classified as Class C body of water. In spite of the unique abundance of biodiversity in Iloilo River, the quality of water in the area has been severely affected by rapid industrialization and urbanization. This study focused on the characterization of bacterial microbiota in the river using 16S rRNA sequencing. Based on 16S rRNA gene sequencing eighteen bacterial family and 19 species were taxonomically identified and classified across the sampling sites. At the family level Microbacteriacea accounted for the most abundant family (8.41%) belonging to the phylum Actinomycetota followed by Flavobacteriaceae (6.34%) under the phylum Bacteroidetes. On the species level the two most dominant species across all sites were Marichromatium gracile (3.62%) and Candidatus aquiluna rubra (3.42%). Most of the identified bacteria were novel and recognized as important human and aquatic pathogens; hence, provide evidence that Iloilo River harbors bacterial population, which might pose health and environmental risks to humans and aquatic lives. There was low microbial diversity index across all sites. Analyses of the selected physicochemical parameters such as temperature, turbidity, salinity and total suspended solids (TSS) pH and dissolved oxygen (DO), indicate that the values were within the national standard limit for Class C Water Body Classification. [ABSTRACT FROM AUTHOR]

Determination of the longitudinal dispersion coefficient (LDC) is fundamental to the development of strategies for environmental management of river systems. This paper presents an integrated model for an estimation of the longitudinal dispersion coefficient by a fusion of optimized intelligent models (optimized neural network (ONN), optimized fuzzy inference system (OFIS), and optimized support vector regression (OSVR)) via committee machine (CM), with optimization done by the Bat-inspired algorithm (BA). The optimization eliminates the associated loss of accuracy of the intelligent models, which is a direct consequence of an improper adjustment of parameters (weights and biases in the neural network, membership's functions in the fuzzy inference system, and user-defined parameters in support vector regression). Data gathered from literature are employed to validate the proposed integrated model. A comparison between the optimized models and a committee machine, based on statistical parameters, shows that the committee machine model can attain high accuracy. Sensitivity analysis (SA) shows the contribution of each optimized model to the committee machine and ranks the contribution of the optimized models in ascending order as optimized neural network, optimized fuzzy inference system, and optimized support vector regression, each significantly correlated with the accuracy of longitudinal dispersion coefficient prediction. HIGHLIGHTS In this study, the longitudinal dispersion coefficient (LDC) is modeled.; Optimized models (OMs; OSVR, ONN, and OFIS) are employed for modeling purposes.; The bat-inspired algorithm (BA) is utilized for improving intelligent models.; The OMs are integrated by a committee machine (CM) with a BA combiner.; The CM generates outstanding results.;

Sensor networks are used in an increasing number and variety of application areas, like traffic control or river monitoring. Sensors in these networks measure parameters of interest defined by domain experts and send these measurements to a central location for storage, viewing and analysis. Temporal graph data models, whose nodes contain time-series data reported by the sensors, have been proposed to model and analyze these networks in order to take informed and timely decisions on their operation. Temporal paths are first-class citizens in this model and some classes of them have been identified in the literature. Queries aimed at finding these paths are denoted as (temporal) path queries. In spite of these efforts, many interesting problems remain open and, in this work, we aim at answering some of them. More concretely, we characterize the classes of temporal paths that can be defined in a sensor network in terms of the well-known Allen’s temporal algebra. We also show that, out of the 8192 possible interval relations in this algebra, only 11 satisfy two desirable properties that we define: transitivity and robustness. We show how these properties and the paths that satisfy them are relevant in practice by means of a real-world use case consisting of an analysis of salinity that appears close to the Scheldt river in Flanders, Belgium, during high tides occurring in the North Sea.

Platyhelminths belonging to the family Clinostomidae (Digenea) have a worldwide distribution and are known to infect piscivorous birds through their intermediate hosts, usually fish species. In the present study, clinostome metacercariae were collected from fish hosts, including Channa punctata (Bloch 1793) (n = 25) and Trichogaster fasciata Bloch and Schneider 1801 (n = 25), from a freshwater system in India. The experimental infection of cattle egrets, Ardea (Bubulcus) ibis Linnaeus 1758, with some of the live metacercariae found in the present study was successful. Live adult parasites were obtained from the buccal cavity of the birds. Both metacercaria and adult specimens were subjected to molecular studies to obtain the sequences of 28S, ITS1, and ITS2 (nuclear rDNA) regions. The parasites were found to belong to three species, Clinostomum giganticum Agarwal 1959; C. piscidium Southwell and Prashad 1918; and Euclinostomum heterostomum (Rudolphi 1809). Phylogenetic analyses of the sequences obtained from the adults and metacercariae established a link between the metacercariae in the fish hosts and adults in the avian host, which is essential to elucidate their partial life cycle and specify morphological characteristics in the metacercarial stage. [ABSTRACT FROM AUTHOR]

The main measure of a river system is commonly accepted to be its catchment area, which determines its main function, i.e., collecting precipitation. However, the river basin also has a volume and a vertical size. The need to take into account the volume of a river basin and to develop the concept of its vertical size (conventionally, "thickness") stems from both general methodological considerations and the available experience of hydrological studies. A system of new estimates of the "thickness" and volume of a basin is proposed to characterize, in particular, its cut depth, the vertical dissection, the "thickness" of the zone of active water exchange, etc. These characteristics can significantly improve the efficiency of the methods of structural–hydrographic indication in the analysis of erosion–accumulation processes, solid runoff, and, in regions with the obvious predominance of groundwater inflow, in what regards the parameters of water flow. The efficiency of the proposed characteristics is demonstrated in the analysis of river systems developing under contrast geological conditions, i.e., in the Mountain Crimea and in the southern sector of Caucasian Black Sea coast. The extension of the instrumentation, the improvement of the detail and information content of relief analysis can be of universal value and can be widely applied in the Earth sciences. [ABSTRACT FROM AUTHOR]

To compare body shape variations and meristic plasticity among four populations of Alburnoides idignensis fish from Aab-barik, Aab-Sardeh, Darband and Sarab-e Kayvareh rivers in Tigris River Drainage, Persian Gulf Basin of Iran. Geometric morphometric method was used to compare shape data extracted by recording 15 landmark points on 2-D pictures of 94 specimens collected from the rivers by electrofishing and a seine net. The Principal component analysis, Canonical Variate analysis and MANOVA analysis were used to examine shape differences among the populations. Eight meristic traits including number of lateral line scales (LL), scales above and below LL to ventral fin, pre-dorsal scales, dorsal, anal, pectoral and pelvic branched rays were counted under a stereomicroscope and mean number of the data were compared by Kruskal–Wallis and ANOVA in SPSS software. Significant differences were found among the four populations in all meristic traits but the number of LL scales and in their body shape, separating them from each other. Results revealed that the studied populations have some differences in meristic characters and in the shape and size of the head, body, caudal peduncle and ventral and anal fin position.

The Trinity bristle snail (Monadenia setosa) is listed as a threatened species under the California Endangered Species Act (CESA). In northern California, populations of this endemic terrestrial gastropod occur in rare, isolated, and highly fragmented locations within the greater Trinity Basin. Since 1952 when it was originally described, the taxonomic status of the Trinity bristle snail has been questioned based on unpublished information limited in geographic scope and sample size, which resulted in the taxon being reduced from species status (M. setosa) to subspecific status (M. i. setosa) within the Redwood sideband (M. infumata) species complex. Primary objectives of the present study were to: 1) use DNA extraction and PCR sequencing to gain insight into patterns of genetic variation and phylogenetic relationships among a larger sample of endemic populations of the Trinity bristle snail; 2) re-evaluate the systematic and taxonomic status of the species using outgroup analysis and references samples from sympatric ecologically co-occurring taxa within the genus Monadenia; and 3) evaluate the potential biogeographic effects of major riverine systems on genetic differentiation among relic and disjunct populations within the Trinity Basin. Results of the DNA sequence analysis using several different tree re-construction methods revealed that subspecies of the Redwood sideband (M. i. subcarinata), Yellow-based sideband (M. i. ochromphalus), and the Trinity bristle (M. i. setosa) exhibited a phylogenetic signal at > 95% species probability. Except for the Yellow-based sideband, molecular evidence detected the presence of several morphologically cryptic subclades within each species clade formerly undescribed by the scientific community. Syntopic ecological relationships between subclades of the Trinity bristle snail and the Redwood sideband occurred in several areas within the geographic range of the Trinity bristle snail, which indicated that these subclades were conservatively differentiated at the subspecific level. A Bayesian coalescent tree showed that genetic variation among allopatric subclades of the Trinity bristle snail and the Redwood sideband were congruent with hydrological discontinuities associated with site-specific riparian stream corridors and the primary river systems within the Trinity Basin. Correlation analysis revealed a pattern of area effects, wherein sparsely bristled Trinity bristle snails were generally found to the northwest and more abundantly bristled individuals to the southeast in relation to primary river corridors that bisect the central Trinity Basin. A similar but opposite trend was observed in the directional pattern of banding. Here the most conspicuously banded individuals were found in samples distributed to the northwest while individuals with less conspicuous banding patterns occurred in a more southeasterly direction in relation to primary riverine corridors. These geographic patterns of bristles and bands appeared to reflect shallow clines that were evident in samples of both the Trinity bristle snail and the Redwood sideband. Parsimony character state reconstructions revealed that the presence of bristles and conspicuousness of bands was widespread among genetic samples, but these attributes did not provide a definitive morphological character that could be used to distinguish among co-occurring taxa.

[Display omitted] • China's large river sediment loadings and runoff have not universally synchronously changed in the past 20 years. • There were 9/13 of large river systems showed downward trends of annual sediment loadings. • Lower reaches of the Yellow River had the maximum annual average sediment loadings. • Runoff volume accounted for over 30% of sediment loading variations among all river systems. • Afforestation plays a crucial role in reducing sediment in arid regions. Understanding the relationship between sediment loading and its environmental implications in river systems is crucial for water resource management and environmental protection. This study explored the spatiotemporal characteristics of sediment loading and their environmental relationships in seven large rivers in China, aiming to quantify the contributions of various factors to changes in sediment transport. Monitoring data spanning twenty-one years (2002 to 2022) on sediments, hydrology, and the environment collected by sixty-five stations were analysed. The multivariate statistical techniques employed included Spearman's correlation analysis, principal component analysis, and multivariate regression modeling. The results show that sediment transport in various river systems exhibited spatial heterogeneity, the maximum annual average sediment loadings (1.59 × 108 t/yr) occur in the lower reaches of the Yellow River, the middle reaches have the highest sediment concentration (41.54 kg/m3), followed by the downstream of the Yellow River (5.85 kg/m3). Sediment loading and runoff changes in the basins did not adhere universally to synchronous patterns. Eleven of the thirteen basins of these river systems showed upward trends in annual runoff volume, whereas nine basins showed downward trends in annual sediment loading. Runoff volume accounted for over 30 % explanatory of sediment loading variations in all seven large river systems, with the Yangtze, Huaihe, Qiantang, and Songhua rivers surpassing 60 % of the explanatory power. The Normalized Difference Vegetation Index of all watersheds showed an increasing trend, whereas the index of nine of the thirteen watersheds was correlated negatively with sediment transport. The influence of human activities on basin sediment transport was higher than that of natural resilience, whereas afforestation significantly reduced sediment in arid regions. This study provides insight into the temporal and spatial characteristics of sediment loadings and the driving effects of environmental factors, which has great significance for watershed environmental management. [ABSTRACT FROM AUTHOR]

In this paper, the terrain characteristics of Al-Sharhani drainage basin and its secondary basins were studied, which is located in the eastern parts of Misan Governorate in southern Iraq, within the eastern Tigris region. The study was conducted using 5 geomorphometric parameters listed in Table 1. with the use of the SRTM (Digital Elevation Model - DEM) and Landsat ETM+7 satellite image with a resolution of 30 m for the American satellite, as well as 1/50000 1/100000 topographic maps, and 1/250000 geological maps, the Spatial databases were created, using a GIS environment. The results showed that there is a direct influence of natural factors (surface, climate and geological structure) in the formation of the basin's topography features. The results also indicated that the relief ratio was 9.849 m/km, which is a low value that reflects the characteristics of the plateau in the region, and the relative relief value was 3.345 m/km, and the relationship was negative between the drainage basin area and the relative relief values. As well as the hypsometric integration value, which is 0.681 km2 /m, which is a low value because the basin is at the beginning of the geomorphological development stage, the ruggedness number was 0.415 which is a low value due to the low density of the discharge, while the texture ratio was 7.149 streams/km, this value indicates that the basin has a medium texture. [ABSTRACT FROM AUTHOR]

Background and aims: The Elqui river basin is located north of the Coquimbo Region, in the semiarid zone of Chile. This body of water is particularly important due to the economic activities it supports and its high environmental vulnerability. The objective of this study was to determine the diversity and floristic composition of macrophytes of the Elqui river basin. M&M: Twenty sampling stations with plots of 1 m2 were distributed in the three sub-basins that make up the study area. Inside each plot, all plant species were recorded along with their respective abundances. In addition, in each station some environmental variables were measured, which were analyzed together with the biological data. Results: A total of 51 macrophyte species and one alga were identified, with dominance of native elements with emergent habit. Statistical analyses indicate moderate differences regarding the floristic composition of the three sub-basins compared; these are mainly concentrated in the Turbio river. The analysis of the environmental data indicates that the variables that most influence the composition of species in the study area are: altitude, total suspended solids, redox potential and water depth. Discussion: Studies on macrophytes at the hydrographic basin level are practically null in Chile. This type of information increases knowledge on biodiversity and allows a more efficient management of continental aquatic systems. [ABSTRACT FROM AUTHOR]

Transportation networks are used in many application areas, like traffic control or river monitoring. For this purpose, sensors are placed in strategic points in the network and they send their data to a central location for storage, viewing and analysis. Recent work proposed graph databases to represent transportation networks, since these networks can change over time, a temporal graph data model is required to keep track of these changes. In this model, time-series data are represented as properties of nodes in the network, and nodes and edges are timestamped with their validity intervals. In this paper, we show that transportation networks can be represented and queried using temporal graph databases and temporal graph query languages. Many interesting situations can be captured by the temporal paths supported by this model. To achieve the above, we extend a recently introduced temporal graph data model and its high-level query language T-GQL to support time series in the nodes of the graph, redefine temporal paths and study and implement new kinds of paths, namely Flow paths and Backwards Flow paths. Further, we analyze a real-world case, using a portion of the Yser river in the Flanders’ river system in Belgium, where some nodes are equipped with sensors while other ones are not. We model this river as a temporal graph, implement it using real data provided by the sensors, and discover interesting temporal paths based on the electric conductivity parameter, that can be used in a decision support environment, by experts for analyzing water quality across time.

To compare body shape variations and meristic plasticity among four populations of Alburnoides idignensis fish from Aab-barik, Aab-Sardeh, Darband and Sarab-e Kayvareh rivers in Tigris River Drainage, Persian Gulf Basin of Iran. Geometric morphometric method was used to compare shape data extracted by recording 15 landmark points on 2-D pictures of 94 specimens collected from the rivers by electrofishing and a seine net. The principal component analysis, Canonical Variate analysis and MANOVA analysis were used to examine shape differences among the populations. Eight meristic traits including number of lateral line scales (LL), scales above and below LL to ventral fin, pre-dorsal scales, dorsal, anal, pectoral and pelvic branched rays were counted under a stereomicroscope and mean number of the data were compared by Kruskal--Wallis and ANOVA in SPSS software. Significant differences were found among the four populations in all meristic traits but the number of LL scales and in their body shape, separating them from each other. Results revealed that the studied populations have some differences in meristic characters and in the shape and size of the head, body, caudal peduncle and ventral and anal fin position. [ABSTRACT FROM AUTHOR]

Sediment is a universal issue that is generated in the river catchment and affects the river flow, reservoir capacity, hydropower generation and dam structure. This paper aims to present the result of experimentation in sediment load estimation using various machine learning algorithms as a powerful AI approach. The data was collected from eight locations in upstream area of Ringlet reservoir catchment. The input variables are discharge and suspended solid. It was found that there is strong correlation between sediment and suspended solid with correlation coefficient of R = 0.9. The developed ML model successfully estimated the sediment load with competitive results from ANN, Decision Tree, AdaBoost and SVM. The best result was produced by SVM (v-SVM version) where very low RMSE was generated for both training and testing dataset despite its more complicated hyperparameters setup. The results also show a promising application of machine learning for future prediction in hydro-informatic systems. [ABSTRACT FROM AUTHOR]

The extent to which soil bioengineering preserves the ecological functions of riverbank vegetation beyond erosion control remains largely unexplored. This study compared the functional response of plant communities on soil-bioengineered riverbanks with those on natural and hard-engineered (ripraps) riverbanks across 124 sites in Quebec, Canada. We hypothesized that the Community Weighted Means (CWM) of 10 functional traits and three ecological attributes relevant in a riparian context and based on 356 plant taxa would be similar between bioengineered and natural sites, while functional diversity measured as richness (FRic) and dispersion (FDis) would be higher in bioengineered sites due to the diverse conditions (substrate, microhabitats). Contrary to expectations, we found trait-specific results. Compared to ripraps, natural sites were dominated by plants that were taller and had lighter seeds, as well as higher dispersion in specific leaf area, height, and seed mass, higher FRic, more dispersion of propagules by water and less by animals, and more plants with vegetative reproduction, shade tolerance, wetland-affinity, native, and fewer ruderal species. Bioengineered sites had intermediate mean trait values and dispersion, and only small differences among the three techniques applied (pure, keyed, and mixed) regarding the proportion of living and mineral material. Consistent with a previous study that used the same set of sites, we found higher plant cover, species richness, and diversity in natural sites compared to ripraps, with bioengineered sites falling in between the two. Bioengineering can partially reproduce natural riparian plant communities both taxonomically and functionally. Practitioners should consider functional diversity in their designs. • Bioengineering may partially restore functionality of riverbank plant communities. • Functional response of riparian vegetation to soil stabilization is trait-specific. • Riverbank stabilization should consider trait diversity as well as species identity. [ABSTRACT FROM AUTHOR]

This study investigated the concentrations of 39 polybrominated diphenyl ether (PBDE) congeners in sediments from three rivers in the western Niger Delta of Nigeria that have been affected by pollution from urbanization and industrial activities. The Σ39 PBDE concentrations in sediments from these rivers ranged from 0.29 to 95.5, 5.15 to 121, and 0.73 to 66.1 ng g−1 for the Afiesere (AR), Edor (ER), and Okpare Rivers (OR), respectively. The homologue distribution patterns indicated the prominence of tetra- and penta-BDE congeners in sediments from these rivers. The ecological risk assessment results showed that the penta-BDEs were the primary source of risk to sediment-dwelling organisms in these rivers. However, the human health risk assessment indicated negligible risks for exposure of both adults and children to PBDEs in these sediments. The source apportionment suggests that the PBDE contamination in these river sediments was derived from long-distance migration, debromination of highly brominated congeners, and commercial penta-BDEs. These results reflect the use of penta-BDE formulations in this region rather than octa- and deca-BDE formulations. • Sediments from these rivers are contaminated with PBDEs. • Industrial and urban activities are potent contributors of PBDEs to the sediment. • Tetra and penta-BDEs were the dominant species in sediments from these Rivers. • Penta-BDEs in these sediments are of potential risk to the ecosystem. • PBDE profiles in these sediments reflect the use of penta-BDE formulation. [ABSTRACT FROM AUTHOR]

Pesticides are chemical compounds used worldwide for different purposes. These chemicals are well known for their long life, high toxicity, and slow degradation process. Many developed countries including South Asian countries banned the use of pesticides for their adverse effects. However, several pesticides are found incessantly in water and soil. To highlight the recent situation of pesticide contamination in South Asian river systems, we have studied 136 relevant articles published from 2015 to 2020. Articles were gathered using several commonly available search engines and organized according to information related to river systems of South Asian countries. After thoroughly examining those research articles, we summarized that most of the river systems are contaminated by pesticides, where DDTs, HCHs, endosulfan, heptachlor, and chlorpyrifos are the key recognized compounds among them. Comparing the level of pesticides with standard guidelines, we found that the Tapi River and Chilika Lake of India are considerably more contaminated than other river basins. Multivariate analyses identified the industrial discharge and agricultural run-off of chemicals as the probable sources of pesticides in these rivers. By analyzing the amount of annual pesticide production, their use, and accordingly their considerable presence in the water systems of the South Asian countries, it is evident that the banned pesticides are used regularly by these countries and thus contaminating the environment. Therefore, the formulations of appropriate rules and their enforcement to control the manufacture and solicitation of such pesticides are an urgent need to save the environment.

More frequent and more severe forest fires mean more severely burned wood in streams. Instream wood provides habitat complexity, alters geomorphology, retains organic and inorganic material, promotes hyporheic flow and acts as substrate for biofilm and invertebrates. However, little is known about instream wood functions in fire‐prone biomes and how they combine with wood burning levels to guide postfire management efforts.Over 3 years, we tracked instream wood following forest fires in central Portugal. We examined for the first time the influence of burning level, season and a large suite of driving factors on the likelihood of four different functions having primary ecological consequences—retention of organic matter, serving as substrate for aquatic biota, being key pieces forming wood jams and deflecting flow including pool habitat formation.One of the main ecological functions of wood in rivers is to provide substrate for vegetation, periphyton, biofilm and oviposition. Our results show that this can be negatively affected when the wood is severely burned.Except for jam formation, the probability of each stream wood function changed markedly with season and the probability of non‐function was nearly twice as high in the Euro‐Mediterranean dry season than in the wet season.More anchored and decayed wood increased the probability of all functions, whereas the effect of submergence depended on the function. Challenging the 'size paradigm' that larger sized pieces provide more function, our data suggest that the effect of size is function‐specific.Synthesis and applications. We show how postfire stream restoration success can be maximized by selecting the most appropriate wood and taking advantage of attribute‐function relationships. We urge managers to refrain from removing wood or to selectively remove the most severely carbonized only, allowing the persistence of great potential to provide substrate for stream biota. The non‐attraction of severely burned wood as substrate can be compensated for by other wood with attributes enhancing this function, such as wood deeper within the bankfull area, and with large diameters. These results will help to inform successful management, as is increasingly asked from restoration ecology. [ABSTRACT FROM AUTHOR]

Significant threats to marine biodiversity, water resources, and coastal sustainability can be directly and indirectly linked to degraded river systems. It is possible that the restoration of the Gulf of Mexico due to chronic and episodic factors will be much improved if the power of the Mississippi River can be fully harnessed. Doing so will require the recognition of the river’s importance and the commitment of our entire nation to restore coastal Louisiana. Research conducted at the Bohemia Spillway, a 12-mile stretch along the eastern bank of the Mississippi, in southeastern Louisiana may provide some insights into how the River can be used as a tool for restoration. The purpose of this study is to gather observational, baseline data from a variety of parameters aimed at understanding the structure and function of the Bohemia Spillway’s ability to resist land loss. The conditions relative to the Bohemia Spillway are important for restoring coastal Louisiana but the solutions will need to come down from as far away as the Rocky Mountains, Appalachian Mountains, and everything in-between.

Through the diversity of criteria and stakes, the uncertain nature of the entailed phenomena and the multi‐scale aspects to be taken into account, a river restoration project can be considered as a complex problem. Integrative approaches and modelling tools are thus needed to help river managers make predictions on the evolution of hydromorphological, socio‐economic, safety and ecological issues. Such approach can provide valuable information for handling long‐term management plans that consider the interaction and the balance of stakeholders interests and river system functioning. In this paper, we present a probabilistic participatory modelling (PM) method that assesses the effects of given restoration actions, knowing the hydromorphological modifications that they may induce on the safety, ecological and socio‐economic aspects with the help of local stakeholders through several workshops. To support this strategy, we used Bayesian networks (BNs) as modelling tools as their causal graphs can combine multidimensional knowledge and data from diverse natures. We introduce the causal graphs elaborated with the help of the stakeholders and convert it into BNs that can assist restoration decisions by considering the available decision and utility functions to provide guidance to decision‐makers. This was applied to the "Lac des Gaves" reach in the Hautes‐Pyrénées, France, a reach that has gone through severe sediment extractions for over 50 years. Each network represents possible restoration decisions linked to one of the observed issues. The paper demonstrates how BNs used as a decision support system (DSS) can help to assess the influence of given management strategies on the river system with the consideration of stakeholders' knowledge and integration in all the modelling process. [ABSTRACT FROM AUTHOR]

In this study, the concentrations of Zn, Cr, Ni, Cu, Pb, As, Cd, and Hg in the surface sediments of 94 sites sampled from six water systems in the Lake Taihu Basin in China were measured, and the pollution risks and sources of the metals were identified. The results showed that the mean concentrations of Zn, Cr, Ni, Cu, Pb, As, Cd, and Hg in the riverine surface sediments were 163.6, 102.5, 45.5, 44.7, 37.0, 13.3, 0.5, and 0.1 mg/kg, respectively, higher than the corresponding background values (except for Hg). According to the geoaccumulation index (Igeo), the Pb, Ni, Zn, Cu, and Cd concentrations in the riverine surface sediments were generally at low levels of pollution. Based on a pollution load index (PLI) evaluation, the Pb, Ni, Zn, and Cu concentrations in the riverine surface sediments were generally at moderate levels of pollution. According to the thresholds of potential ecological risk, the Cd and Hg concentrations in the riverine surface sediments exhibited moderate potential ecological risks. Multivariate statistical analysis indicated that the Pb in the riverine surface sediments primarily originated from domestic sewage, agricultural wastewater discharge, and petroleum combustion; the concentrations of Cr, Ni, and Zn were influenced by the electroplating and alloy manufacturing industries; the concentrations of Cu and As mainly originated from pesticide use and industrial wastewater discharge; and those of Cd and Hg primarily stemmed from industrial wastewater discharge. This research provides information regarding metallic contamination and the possible associated ecological risks to benthic organisms in the surface sediments of river systems and is useful for developing sustainable strategies for environmental pollution control and management in the Lake Taihu Basin. [ABSTRACT FROM AUTHOR]

Soils contain an increasing number of different pollutants, which are often released into the environment by human activity. Among the “new” potential pollutants are plastics and microplastics. “Recognized” pollutants such as heavy metals, of geogenic and anthropogenic origin, now meet purely anthropogenic contaminants such as plastic particles. Those can meet especially in floodplain landscapes and floodplain soils, because of their function as a temporary sink for sediments, nutrients, and pollutants. Based on a geospatial sampling approach, we analyzed the soil properties and heavy metal contents (ICP-MS) in soil material and macroplastic particles, and calculated total plastic concentrations (Ptot) from preliminary studies. Those data were used to investigate spatial connections between both groups of pollutants. Our results from the example of the Lahn river catchment show a low-to-moderate contamination of the floodplain soils with heavy metals and a wide distribution of plastic contents up to a depth of two meters. Furthermore, we were able to document heavy metal contents in macroplastic particles. Spatial and statistical correlations between both pollutants were found. Those correlations are mainly expressed by a comparable variability in concentrations across the catchment and in a common accumulation in topsoil and upper soil or sediment layers (0–50 cm). The results indicate comparable deposition conditions of both pollutants in the floodplain system.

The development of the Ohře River near Žatec between the Late Glacial Maximum (LGM) and present time was studied to obtain its natural trajectory and thus to understand the role of human impact on floodplain development. The study was based on geomorphic research, sampling and dating fluvial sediments by optically stimulated luminescence (OSL) and anthropogenic contamination by Sn since 16th century. During the LGM and the Pleistocene/Holocene transition (P/H), the river valley was shaped by large, incising meanders creating the entire valley floor. The Holocene river, due to decreased channel forming discharges, only slowly continued the LGM and P/H trajectory by cut-offs of the large palaeomeander necks and channel belt narrowing and incision. The last Holocene incision step was likely triggered by hydrological extremes of the Little Ice Age. The LGM and P/H Ohře River consequently changed from meandering to low sinuous, incised in the valley floor; this incision was completed by river engineering in the 20th century. The Ohře River development can thus be rationalised neither by traditional terrace-step formation model nor by model of the Anthropogenic aggradation.

Humans have, by biological necessity, always lived in watersheds. This article provides an overview of humans' relationship to these watersheds as an introduction to a special issue of Thesis Eleven on watersheds. It describes the basic functioning of watersheds, how humans have always depended on them, and how they have slowly begun to manipulate them. Humans across the planet began by making strategic adjustments to water's downward flow to aid the procurement of water and fish. As small states, empires, and finally the Industrial Revolution unfolded, these interventions became more numerous with greater environmental impacts. The rate of riverine exploitation increased dramatically post-Second World War in line with the Great Acceleration. This, in turn, created our current worldwide ecological crisis. This crisis particularly affects the planet's watersheds, and in turn, humans. The article ends with the assertion that studies of such a complex event are by necessity multi-disciplinary and interregional. It then outlines the contents of this special issue which examines watersheds in Asia, America and Australia. [ABSTRACT FROM AUTHOR]

Intense land use and river regulations have led to the destruction of wetland habitats in the past 150 years. One plant that is affected by the reduction in appropriate habitats is the macrophyte Stratiotes aloides which has become rare in several areas. The preservation of genetic diversity within a species is a prerequisite for survival under changing environmental conditions. To evaluate the level of genetic diversity within and among populations of Stratiotes aloides, we investigated samples from waterbodies across Europe using AFLP. Low genetic diversity among samples from the same population was found, proving that stands consist of few clones which propagate clonally. Nevertheless, most populations showed differences compared to other populations indicating that there is genetic diversity within the species. The analyzed samples formed two groups in STRUCTURE analyses. The two groups can be further subdivided and mainly follow the major river systems. For conserving the genetic diversity of Stratiotes aloides, it would thus be preferable to focus on conserving individuals from many different populations rather than conserving selected populations with a higher number of individuals per population. For reintroductions, samples from the same river system could serve as founder individuals.

In ungauged catchments, flood hydrographs are usually simulated/reconstructed by simple rainfall-runoff and routing models. Horton’s and Schumm’s ratios serve as the input data for many of these models. In this paper, more than 800 Carpathian catchments (up to 35.2 km2 in area) were investigated in context of the “Horton’s and Schumm’s laws”. Results reveal that the “law of stream number” and “law of stream areas” are fulfilled in almost all catchments. The mean that values of the bifurcation ratio (RB) and the area ratio (RA) reach 3.8 and 4.8, respectively, and are thus comparable to values reported in other regions of the world. However, the “law of stream lengths” is not fulfilled in more than half of the catchments, which is not consistent with many theoretical studies reported in the literature. Only 383 (48%) catchments fulfill the “law of stream length”, with the mean value of the length ratio (RL)=2.3. There was no relationship found between the geological/geomorphological settings that influence river system development and the spatial distribution of catchments where the “law of stream length” was or was not was fulfilled. A similar conclusion was reached for the spatial distribution of the RB, RL, and RA ratios. These results confirmed that the use of Horton’s and Schumm’s ratios for the evaluation of the influence of geological/geomorphological settings on the river system development is limited. Among the lumped hydrological models, those requiring the RB, RL, and RA ratios have been extensively studied over last decades. This study suggests that the application of these models may be limited in small catchment areas; therefore, more attention should be placed on the development of hydrological models where the RB, RL, and RA ratios are not necessary.