Stream Quality Research Articles

State Drainage Laws Muddy the Goals of the US Clean Water Act (1972)

The US Congress passed the Clean Water Act in 1972 to protect and restore America's waterbodies by regulating pollutant discharges from point sources such as industrial plants and sewer pipes. Over the years, Congress expanded the law to include non-point sources like polluted runoff from roads and agricultural areas. However, routine agriculture drainage maintenance activities, like continuously farmed wetlands and drainage ditch dredging, are exempted under the Clean Water Act. These exemptions allow sediment pollution to continue to be a major issue in agricultural streams and waterbodies managed by drainage districts. We examine the shortcomings of the Clean Water Act to address sediment pollution from the perspective of routine agricultural activities like drainage ditch maintenance and offer policy recommendations to mitigate its impacts. We discuss the exclusion of agricultural sediment originating from these activities as a major non-point pollution source under the Clean Water Act, the consequences of sediment pollution on aquatic ecosystems and stream water quality in agricultural streams, and the need for monitoring and regulation of sediment discharge from farming practices. In our analysis, we also consider the interaction between the state drainage laws and federal regulations. Finally, we seek to address gaps in the current regulatory structure and offer suggestions regarding better protection of water quality and ecosystem health in drainage districts.

SEASONAL ANALYSIS OF AQUATIC WATER QUALITY IN A FORESTRY AREA, MS, BRAZIL

Water quality is one of the topics of greatest concern worldwide, as it is a fundamental resource for life, whose constant monitoring is necessary. The objective of this work was to carry out seasonal monitoring of water quality in the Urutu-MS stream, occupied by more than 50% of eucalyptus silviculture forests. Water samples were collected from five points seasonally between autumn 2019 and summer 2020. Twenty-three parameters included such as temperature, pH, Dissolved oxygen, Conductivity, Alkalinity, Organic matter, Chloride, Sulfate, Total iron, Color, Turbidity, Total dissolved solids, Total suspended solids, Chemical Oxygen Demand, Total phosphorus, Hardness, Aluminum, Manganese, Magnesium, Sodium, Calcium, Copper and Dissolved Iron. The results showed that there is a difference in water quality between the seasons due to the different concentrations of physicochemical parameters. Spring was in class II, while the others were in class I, showing the influence of the onset of rain after the dry winter. Interactions between parameters followed conventional associations such as Alkalinity and Conductivity, SDT and Conductivity, Color and Turbidity, SST and Turbidity, Conductivity and Calcium, Conductivity and Magnesium. Alkalinity and TDS being the main parameters influenced by seasonality. Keywords: Paraná Watershed, Land use and Land Cover, Cerrado, Silviculture, Seasonality.

Assessment of exurban expansion on water quality in Rock Creek of the Yellowstone River in southcentral Montana, USA

Exurban expansion can degrade significantly stream water quality. This study was conducted on Rock Creek of the Clark’s Fork of the Yellowstone River in southcentral Montana, USA. The impact from recent exurban expansion was evaluated by a baseline study measuring total suspended solids (TSS), total phosphorus (TP), total nitrogen (TN) and nitrites (NO2) and nitrates (NO3) together. This was part of a larger study by Montana Department of Environmental Quality to assess water quality, identify sources of pollution and develop total maximum daily loads (TMDL). Water samples were measured for these analytes at nine (2022) and 11 (2023) locations with different land-uses over seven periods (both years). Seasonal spikes, corresponding to runoff (2022, late May), occurred in TSS, TP and TN. Data from 2023 showed similar but reduced levels occurring in June for TSS and TP. Total suspended solids, TP, NO2 and NO3 concentrations increased by location year over year, 2022 to 2023. The high relative concentrations of NO2 and NO3 in Rock Creek are primarily associated with exurban expansion, a significant threat to stream quality and wildlife habitat in Montana. The results will assist county planners in land use decisions.

Quantification and characterization of municipal solid waste at aler dumpsite, Lira City, Uganda: Assessing pollution levels and health risks

Managing municipal solid waste (MSW) in urban areas of developing countries is a significant challenge due to rapid urbanization and inadequate infrastructure. This study aims to quantify the MSW at Aler dumpsite in Lira City, Uganda, and assess the associated environmental and health risks. Our findings revealed a daily dumping rate of 7.38 tons, predominantly organic waste. Leachate from the site exceeded WHO limits for nutrients and heavy metals, with exceptionally high amounts of cadmium (Cd) found in soil (4.8 mg/kg) and vegetables. The water quality in nearby streams was poor, rendering it unfit for consumption due to elevated ion and nutrient levels. Health risk assessments indicated significant non-carcinogenic risks from heavy metal ingestion, with a hazard index (HI) of 4.6 for adults and 9.6 for children. While dermal exposure risks were generally low, children were at risk from stream 1 (HQderm = 1.165). Vegetable analysis revealed levels of lead (Pb), cadmium (Cd), zinc (Zn), and nickel (Ni) above safe doses, posing significant non-carcinogenic risks. To address these issues, we recommend increasing public awareness to avoid consuming water and vegetables from areas around the dump site. Additionally, we suggest that the responsible authorities improve MSW management by constructing sanitary landfills to minimize water, soil, and plant pollution from landfill leachate.

Long-term effects of wildfires on river water quality: a comprehensive review of the variability of water quality in South Korea

ABSTRACT After wildfires, the loss of the humus layer leads to increased runoff and ash-related pollutants entering rivers. This study examined the long-term effects of wildfires on river water quality, focusing on 7 years before and after the wildfire events. We statistically analyzed the changes in the water quality of streams surrounding the wildfire area following a major wildfire. We used eight water quality parameters provided by the National Institute of Environmental Research for the analysis. To assess the impact of the wildfires, we employed t-tests and point-biserial correlation analysis to compare the changes in water quality indicators before and after the wildfires. Additionally, an analysis of variance was conducted to evaluate the impact of three wildfires, each occurring in different periods, on the water quality in a single river basin. The results showed increasing trends in hydrogen ion concentration (pH), electrical conductivity, and dissolved oxygen after the wildfire, whereas biochemical oxygen demand, total phosphorus, and total nitrogen exhibited decreasing trends. The impact of wildfires on changes in suspended solids was relatively minimal. It is expected that the results of this study provide valuable insights into developing water quality management and restoration plans following wildfires.

Forest Dieback Alters Nutrient Pathways in a Temperate Headwater Catchment

ABSTRACTForested headwater catchments ensure good water quality for downstream ecosystems and human consumption. Climate change and the exacerbating likelihood of extreme events elevate the risk of severe forest dieback. However, the effects of forest dieback on the quantity and quality of stream water are not fully understood. Here, we analyse high‐frequency observations of discharge, electrical conductivity (EC), dissolved organic carbon (DOC) and nitrate (NO3N) obtained before, during and after a drought‐induced forest dieback in a headwater stream in the German Harz Mountains. We focus on the characteristics of concentration‐discharge (C‐Q) relationships at the scale of runoff events to assess the effects of forest dieback on the sources, mobilisation and pathways of EC, DOC and NO3N. When comparing pre‐ and post‐dieback conditions, we found a significant increase in runoff efficiency and a doubling of DOC loads exported from the catchment, while DOC concentrations increased only moderately and their C‐Q patterns did not change. EC exhibit no changes in concentrations but a steepening of C‐Q dilution patterns. We explain these findings with a dieback‐induced decrease in evapotranspiration, which leads to more intensive drainage of the upper organic soil layers in the riparian zone. In contrast, we observed a strong increase in NO3N concentrations and fluxes by a factor of ~5, while C‐Q patterns at the event scale changed from enrichment to dilution. We argue that the dieback led to an excess of NO3N on the hillslopes that connect to the stream via surficial flowpaths. In this way, NO3N bypasses the riparian zone, reducing the catchment's efficiency in attenuating this nutrient. Our study emphasises the pivotal role of riparian zones in mediating water quality in headwater streams. Different configurations of the riparian zone and its connection to the hillslopes and the stream network may be a missing piece in explaining differences in water quality responses of catchments to forest dieback.

The Impact of Green Infrastructure on the Quality of Stormwater and Environmental Risk

Increasing urbanization and the associated sealing of areas and the use of storm sewer systems for drainage not only increase the risk of flooding but also reduce water quality in streams into which stormwater is discharged. Green infrastructure (GI) measures are applied with the aim of managing this stormwater sustainably and reducing the associated risks. To this end, a quantitative–qualitative approach was developed to simulate GI—namely, rain gardens, bioretention cells, and vegetative bioswales—at the urban catchment scale. The findings highlight the potential of applying GI measures to managing stormwater more effectively in urban environments and mitigating its negative pollution-related impacts. For the housing estate analyzed, a simulated implementation of GI resulted in a reduction in pollution, measured as total nitrogen (N; 9–52%), nitrate-N (5–30%), total phosphorus (11–59%), chemical oxygen demand (8–46%), total suspended solids (13–73%), copper (12–64%), zinc (Zn; 16–87%), polycyclic aromatic hydrocarbons (16–91%), and the hydrocarbon oil index (HOI; 15–85%). Reducing the concentrations of pollutants minimizes the risk to human health determined via the HOI from a low-risk level to zero risk and reduces the ecological risk in terms of Zn pollution from a significant risk to a low risk of adverse effects. The modeling conducted clearly shows that the GI solutions implemented facilitated a quantitative reduction and a qualitative improvement in stormwater, which is crucial from an environmental perspective and ensures a sustainable approach to stormwater management. Lowering the levels of stormwater pollution through the implementation of GI will consequently lower the environmental burden of pollutants in urban areas.

Impacts of fish pond effluent on the water quality of an afrotropical stream: a comprehensive evaluation using the water quality index

This study highlights the importance of managing fishpond effluent to minimize its impact on aquatic environments. Fish effluents are a major concern worldwide in aquatic environments. It also provides information on the impacts of effluents on the water quality index of streams when released into aquatic environments. Streams and fishponds were sampled bimonthly for two annual cycles, covering different sampling stations both upstream and downstream of the fishpond effluents at 50-m intervals. Water quality parameters associated with in situ conditions were determined in the field. In the laboratory, other physicochemical parameters were determined via proper standard protocols. The results of the study revealed that water quality parameters such as turbidity, total suspended solids, total solids, conductivity, total dissolved solids, dissolved oxygen, biological oxygen demand and organic matter recorded in water samples collected from 50 m upstream at the point of effluent discharge were significantly (p < 0.05) different from those recorded at other sampling stations. The WQI value of the discharge point was higher than the WQI recorded in both the upstream and downstream sections of the stream. The findings of this study showed that the point of discharge of fishpond effluents is particularly concerning for the receiving stream compared with other sampling points. This localized area has experienced marked deterioration in water quality, posing significant threats to the health and biodiversity of aquatic ecosystems. The effluent's impact, though slight when dispersed in the receiving waterbody, underscores the necessity for adequate management practices to mitigate its adverse effects. Effective strategies, including regular monitoring, effluent treatment, and sustainable pond management, are imperative to ensure the long-term health and resilience of the aquatic environment.

Approach to Video Stream Quality Requirements Justification for FPV Control of Unmanned Systems

Currently, hybrid orbital-ground communication networks play a key role in various sectors of the Russian economy, an important part of which are unmanned systems based on FPV control. One of the key elements of such systems is information exchange channels. The main criterion for the success of their objectives is to meet the requirements for the quality of the transmitted video stream, which makes it particularly relevant to substantiate these requirements. The purpose of this article is to present an approach to the quantitative justification of the requirements for the quality of the transmitted video stream. The essence of the presented approach lies in the fact that the required values of the transmitted image quality indicators, used to justify acceptable neural network codecs, are determined by analyzing various video streams, on the basis of which the impacts on the control of unmanned systems that allowed to achieve the goals of their functioning were formed. The main stages of the approach and their logical interrelation are considered. The proposed approach is based on the use of methods of statistical and risk analysis, the theory of experiment planning and probability theory.Scientific novelty of the proposed approach lies in the fact that the requirements to the quality of the video stream transmitted from the unmanned system to the operator, used to justify acceptable neural network codecs, are calculated by analyzing the totality of video streams that allowed to achieve the goals of its functioning, which allows to get rid of the subjectivism inherent in the expert methods currently used to solve this problem.Theoretical significance of the proposed approach lies in the fact that the necessity and possibility of not only substantiating the requirements for the quality indicators of the transmitted video stream for FPV control, but also their correction has been proved. Practical significance. The requirements for the quality indicators of the transmitted video stream obtained using the proposed approach can be further used to justify optimal design solutions for creating information exchange channels between unmanned systems and the operator, which will significantly increase the efficiency of using these systems.

Performance Testing Techniques for Live TV Streaming on STBs

In the realm of live TV streaming, performance testing is critical to ensure seamless delivery and optimal user experience on Set-Top Boxes (STBs). This paper presents a comprehensive exploration of performance testing techniques tailored for live TV streaming on STBs, focusing on methodologies, challenges, and best practices. With the growing demand for high-quality, uninterrupted live TV content, effective performance testing becomes imperative to address issues related to latency, buffering, and overall system reliability. The study begins with an overview of the unique performance challenges associated with live TV streaming on STBs. Unlike on-demand streaming, live TV requires real-time data processing and minimal latency to deliver a continuous viewing experience. The paper categorizes performance testing into several key areas: network performance, system resource utilization, and user experience. Network performance testing evaluates the efficiency of data transmission across various network conditions. Techniques such as bandwidth measurement, latency analysis, and jitter assessment are employed to simulate different network scenarios and determine their impact on streaming quality. These tests help in identifying bottlenecks and optimizing network configurations to support smooth streaming.

Using the proportional dual integral strategy to improve the characteristics of the indirect field-oriented control of DFIG-based wind turbine systems

In this work, a new indirect field-oriented command (IFOC) for wind systems based on a doubly-fed induction generator (DFIG) is designed to get better energy and stream quality. Also, overcoming the problems of IFOC. It is proposed to use proportional dual integral (PDI) controllers in order to replace traditional controllers and augment the robustness of the studied wind turbine system. The proposed IFOC-PDI is a modification of the IFOC, where the basic idea behind the designed technique is to combine a proportional-integral (PI) regulator with an integral term. This technique has been applied to the machine inverter, where the IFOC-PDI aims to calculate reference voltage values. The pulse width modulation (PWM) is used to translate voltage reference values ​​into pulses to run the machine inverter. The main objective of this article is to compare the competence of the IFOC-PDI to that of the IFOC-PI in different tests, including two different wind speed profiles and DFIG parameters variation. The major benefit of this command is a decrease in harmonic distortion of the currents, and active and reactive power (Ps and Qs) fluctuations. The results using MATLAB demonstrated that the IFOC-PDI improved the IFOC-PI in the minimization of stream harmonic distortion (6.63%, 10.42%, and 17.86%) and notable minimization of fluctuations in both Ps (32.08%, 46.24%, and 12.10%) and Qs (45.95%, 66.88%, and 14.49%). Also, the overshoot value of Ps was minimized compared to the IFOC-PI in all tests by ratios estimated at 57.79%, 12.41%, and 33.96%. The steady-state error of Ps was minimized compared to the IFOC-PI in all tests by ratios estimated at 29.43%, 85.88%, and 76.36%. The IFOC-PDI is also very resistant in the case of DFIG parameters variation.

Ce anomaly in hemiboreal headwater streams: An indicator of dominant groundwater flow paths through the catchment

The water quality in headwater streams depends on the groundwater origin and its transport pathways before it eventually discharges as surface water. In this case study, we present the Ce anomaly of over 100 hemiboreal headwater streams in Sweden and discuss the potential of the Ce anomaly to define two stream end members as proxies for the stream origin. The data show a relation between topography and the Ce anomaly, with more negative values (−0.8 to −0.4) in hilly catchments with distinct slopes, defined as an oxidized groundwater end member. The second end member is dominated by groundwater discharge from reduced, organic-rich riparian and wetland soils (reduced groundwater) having small Ce anomalies (−0.3 to zero). Element concentrations show a wide range, depending on the end member of the stream. For example, redox elements (Fe, Mn, S and N) show concentrations up to five times in streams with small negative Ce anomalies (reduced groundwater) compared to the concentrations in streams with large negative Ce anomalies. While element concentrations (of the classic redox elements Fe, Mn, S, N) show seasonal variations due to a summer drought period and the resulting reduced conditions, the Ce anomaly is constant, offering an excellent indicator of the dominant groundwater flow paths regardless of seasonal variations.

Research on the Purchase Intention of Social Commerce Consumers in Video Streams: Dual Pathways of Affection and Rationality.

Social commerce blurs the boundary between online social interaction and online shopping. The emergence of video streams introduces novel marketing modalities to social commerce. However, there is a paucity of comprehensive studies investigating the impact of emerging marketing techniques such as short videos and live streaming on consumer purchase intention. This study employs Bourdieu's conceptual framework to construct a Field Theory-based model, investigating the impact of atmospheric and capital characteristics of social commerce platforms on consumer purchase intention through affective and rational pathways, respectively. A survey involving 515 Chinese social commerce consumers demonstrates that atmospheric characteristics (emotion and social presence) and capital characteristics (information quality and quantity) in video streams enhance similarity and power. Both similarity and power are associated with an increase in consumer purchase intention. This study validates the dual-path influence of social commerce characteristics and discusses theoretical and managerial implications.

Nature-based bank protection measures improve benthic macroinvertebrates in a stream draining an agriculturally dominated watershed

Increased bank erosion is one of the most significant threats to agricultural stream ecosystems. However, it is challenging to ascertain whether bank restoration measures positively affect in-stream habitats and aquatic communities. This study evaluated three nature-based bank protection measures' short-term (2-year) effects on aquatic physical habitat quality and benthic macroinvertebrate communities in a headwater stream in agricultural areas. The results demonstrate that nature-based bank protection measures can significantly improve the quality of aquatic physical habitat in streams. The TPRW (timber piles + riprap + willow cuttings) and WTRW (waste tires + riprap + willow cuttings) measures exhibited the most pronounced improvement in the quality of aquatic physical habitat in streams. The diversity of benthic macroinvertebrates was the highest in the TPRW reach, and the seasons significantly affected the density of benthic macroinvertebrates. The Shannon-Wiener diversity index and Margalef's richness index were the most consistent with the changing trend of physical habitat quality and are effective indicators of the ecological effects of stream restoration measures in our study area. In this study area, TPRW is the preferred measure for streambank restoration of agricultural streams, and WTRW is the alternative measure. However, the ecological effects of WTRW need to be monitored over a more extended period to identify whether there is potential ecotoxicity in the process of weathering and decomposition.

Earth Observation and Geoinformatics to Monitoring the Environmental Status of Urban Streams Inextricably Linked to People's Mental Health.

The general condition of urban watercourses is inextricably linked to ecological balance and public health (physical and mental well-being). Given the vulnerability of these systems to climate change and human pollution, this work aims to demonstrate the effective use of environmental indicators to: a) rapidly assess soil and water conditions near urban streams and b) highlight the importance of geoinformatics and earth observation supported by ground-based techniques. There is a great need for new technology and methods for spatial and temporal monitoring and further quantification of environmental quality in urban streams and the land surrounding them to sensitize policymakers and the public to the environmental degradation of these exceptional habitats and to further protect people's mental health.

Accelerated Bitrate Ladder Creation for Video Live Streaming Using Temporal Layer Injection

Video streaming systems aim to provide high-quality video adapted to clients’ device and network conditions. For this purpose, adaptive streaming architectures encode video content at a variety of quality levels, organized in a bitrate ladder. However, compressing a video into multiple streams is resource-intensive, which may become especially problematic in live streaming applications with real-time demands. Therefore, this paper proposes a novel solution for fast bitrate ladder creation, and provides the requirements for implementation in the H.266/VVC standard. More specifically, the proposed method creates new intermediate combined streams by injecting the lowest temporal layers of a higher-quality augmentation stream in a lower-quality base stream. Since the lowest layers are used as reference by the remaining layers, this procedure indirectly increases the quality of the frames in those untouched remaining layers as well. Although altering the reference frames may cause some drift-error artifacts, we demonstrate that, on average, the quality of the intermediate streams are higher than the base stream. Additionally, we demonstrate that injecting more layers brings both the quality and bitrate closer to that of the augmentation stream. The disadvantage of the combined streams is that their quality fluctuates more than the quality of the source streams, and that they are compressed less efficiently, comparable to going from a slower to fast or faster preset in the VVenC encoder. Most importantly, their main advantage is that they were generated at no significant additional computational complexity. In this way, the proposed method is of great benefit when generating a bitrate ladder of video streams under constrained computational resources. The code has been made open source and is available on https://github.com/IDLabMedia/NALUProcessing .

Assessing Methods to Monitor Aquatic Invertebrates in a Large River: Comparing Rock Baskets and Hess Samplers in the Snake River, Wyoming, USA

Large rivers are difficult to sample due to their size yet critical to monitor because humans heavily rely upon and alter them. Aquatic invertebrates are commonly used to assess the ecosystem quality of streams, but methods to sample large rivers are underdeveloped. We sampled aquatic invertebrates using a Hess sampler and rock baskets in the Snake River near Jackson, Wyoming, USA. Hess samples collected more aquatic invertebrate taxa and a higher proportion of Ephemeroptera, Plecoptera, and burrowing taxa. Rock baskets collected a higher proportion of Trichoptera, filterers, and clinging taxa. Bioassessment metrics differed between sampling methods; richness, diversity, evenness, Ephemeroptera, Plecoptera, and Trichoptera (EPT), and Hilsenhoff’s biotic index produced higher values in Hess samples, and percent EPT was higher in rock baskets. Non-metric multidimensional scaling and analysis of similarity indicated that the samplers collected different assemblages (p &lt; 0.001). The standard error of total invertebrate density was smaller and most taxa were collected with seven replicate samples. Understanding how sampling methods alter the aquatic invertebrates collected will help managers develop monitoring protocols that are best suited to the river and collect the most unbiased invertebrate assemblages.

Inferring Video Streaming Quality of Real-Time Communication Inside Network

Inferring Video Streaming Quality of Real-Time Communication Inside Network

Impact of Human Activities on the Physiochemical Quality of Streams Around Ijeun- Titun and Kuto Community in Abeokuta, Ogun State, Nigeria

Impact of Human Activities on the Physiochemical Quality of Streams Around Ijeun- Titun and Kuto Community in Abeokuta, Ogun State, Nigeria

Four decades of changing dissolved organic matter quality and stoichiometry in a Swedish forest stream

Dissolved organic matter (DOM) concentrations have risen by a factor of two or more across much of Europe and North America during recent decades. These increases have affected the carbon cycle, light regime, drinking water treatability, and the energy and nutrient budgets of lakes and streams. However, while trends in DOM quantity are well characterised, information on how/whether qualitative properties of DOM have changed are scarce. Here, we describe over 40 years of monitoring data from a forested headwater stream in the Gårdsjön experimental catchment, southwest Sweden, which provides a unique record of biogeochemical change, including optical and stoichiometric DOM quality metrics, spanning the entire period of recovery from acidification. For the period 1980–2020 we find a 71% reduction in decadal mean sulphate concentrations, and a similar reduction in inorganic aluminium concentrations, alongside a 64% increase in dissolved organic carbon (DOC) concentrations. Over the same period, colour (absorbance at 420 nm) increased almost twice as much as DOC, whereas dissolved organic nitrogen (DON) increased by only one third as much. These results demonstrate a shift in stream water composition, with DOM becoming dominated by highly coloured, complex, nitrogen-poor compounds. This material is likely more resistant to biological degradation, but more susceptible to photochemical degradation. Changes in DOM stoichiometry could lead to intensified nitrogen and/or phosphorus limitation in surface waters, while increased colour/DOC ratios could intensify light-limitation of primary production beyond that expected from DOC increases alone. We observed increases in organic matter associated metals (iron 117%, organically complexed aluminium 85%) that exceeded the increase in DOC, consistent with their increased mobilisation by more aromatic organic matter. All observed changes are consistent with recovery from acidification being the primary driver of change, implying that past acidification, and ongoing recovery, have profoundly affected terrestrial and aquatic biogeochemistry, ecology and the carbon cycle.