scholarly journals Four Years of Sediment and Phosphorus Monitoring in the Kraichbach River Using Large-Volume Samplers

Water ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 120
Author(s):  
Katharina Allion ◽  
Lisa Kiemle ◽  
Stephan Fuchs
Keyword(s):  
Large Volume ◽  
River Flow ◽  
High Flow ◽  
Sampling Strategies ◽  
Flow Conditions ◽  
Discharge Data ◽  
Transport Dynamics ◽  
Long Period ◽  
River Loads ◽  
Composite Samples

Various sampling strategies come into operation to monitor water quality in rivers. Most frequently, grab samples are taken, but they are not suitable for recording the highly dynamic transport of solids and solid-bound pollutants. Composite samples reduce the influence of input and transport dynamics and are better suited to determine the annual river loads. Large-volume samplers (LVSs) produce both a composite sample over a long period of time and an amount of solids which allows for further analyses. In the small sub-catchment area of the Kraichbach river in Baden-Wuerttemberg (Germany) two LVSs have been installed to sample the river flow. The concentration of solids and phosphorus in the supernatant water and the settled sediment in the sampler have been determined and mean concentrations have been derived. Annual river loads were calculated in combination with discharge data from the nearby gauging station. Two sampling strategies of the LVS were tested and compared. For the first strategy, the LVS was used to collect quasi-continuous composite samples throughout the year, whereas, with the second strategy, samples were taken specifically for different flow conditions (low, mean and high flow). This study compares the advantages and constraints of both strategies. Results indicate that the first strategy is better suited to determine annual river loads. Quasi-continuous large-volume composite sampling is recommended for further monitoring campaigns.

scholarly journals KLT-IV v1.0: image velocimetry software for use with fixed and mobile platforms

2020 ◽  
Vol 13 (12) ◽  
pp. 6111-6130
Author(s):  
Matthew T. Perks
Keyword(s):  
River Flow ◽  
High Flow ◽  
Ground Control ◽  
Control Points ◽  
Flow Conditions ◽  
Mobile Platforms ◽  
Differential Gps ◽  
Ground Control Points ◽  
Image Velocimetry

Abstract. Accurately monitoring river flows can be challenging, particularly under high-flow conditions. In recent years, there has been considerable development of remote sensing techniques for the determination of river flow dynamics. Image velocimetry is one particular approach which has been shown to accurately reconstruct surface velocities under a range of hydro-geomorphic conditions. Building on these advances, a new software package, KLT-IV v1.0, has been designed to offer a user-friendly graphical interface for the determination of river flow velocity and river discharge using videos acquired from a variety of fixed and mobile platforms. Platform movement can be accounted for when ground control points and/or stable features are present or where the platform is equipped with a differential GPS device and inertial measurement unit (IMU) sensor. The application of KLT-IV v1.0 is demonstrated using two case studies at sites in the UK: (i) river Feshie and (ii) river Coquet. At these sites, footage is acquired from unmanned aerial systems (UASs) and fixed cameras. Using a combination of ground control points (GCPs) and differential GPS and IMU data to account for platform movement, image coordinates are converted to real-world distances and displacements. Flow measurements made with a UAS and fixed camera are used to generate a well-defined flow rating curve for the river Feshie. Concurrent measurements made by UAS and fixed camera are shown to deviate by < 4 % under high-flow conditions where maximum velocities exceed 3 m s−1. The acquisition of footage on the river Coquet using a UAS equipped with differential GPS and IMU sensors enabled flow velocities to be precisely reconstructed along a 180 m river reach. In-channel velocities of between 0.2 and 1 m s−1 are produced. Check points indicated that unaccounted-for motion in the UAS platform is in the region of 6 cm. These examples are provided to illustrate the potential for KLT-IV to be used for quantifying flow rates using videos collected from fixed or mobile camera systems.

scholarly journals KLT-IV v1.0: Image velocimetry software for use with fixed and mobile platforms

2020 ◽  
Author(s):  
Matthew T. Perks
Keyword(s):  
River Flow ◽  
High Flow ◽  
Ground Control ◽  
Control Points ◽  
Flow Conditions ◽  
Mobile Platforms ◽  
Differential Gps ◽  
Ground Control Points ◽  
Image Velocimetry

Abstract. Accurately monitoring river flows can be challenging, particularly under high-flow conditions. In recent years, there has been considerable development of remote sensing techniques for the determination of river flow dynamics. Image velocimetry is one particular approach which has been shown to accurately reconstruct surface velocities under a range of hydro-geomorphic conditions. Building on these advances, a new software package, KLT-IV v1.0 has been designed to offer a user-friendly graphical interface for the determination of river flow velocity and river discharge using videos acquired from a variety of fixed and mobile platforms. Platform movement can be accounted for when ground control points and/or stable features are present, or where the platform is equipped with a differential GPS device and inertial measurement unit (IMU) sensor. The application of KLT-IV v1.0 is demonstrated using two case studies at sites in the UK: (i) River Feshie; and (ii) River Coquet. At these sites, footage is acquired from unmanned aerial systems (UAS) and fixed cameras. Using a combination of ground control points (GCPs), and differential GPS and IMU data to account for platform movement, image coordinates are converted to real world distances and displacements. Flow measurements made with a UAS and fixed camera are used to generate a well-defined flow rating curve for the River Feshie. Concurrent measurements made by UAS and fixed camera are shown to deviate by < 4 % under high-flow conditions where maximum velocities exceed 3 m s−1. The acquisition of footage on the River Coquet using a UAS equipped with differential GPS and IMU sensors enabled flow velocities to be precisely reconstructed along a 180 m river reach. In-channel velocities of between 0.2 and 1 m s−1 are produced. Check points indicated that unaccounted for motion in the UAS platform is in the region of 6 cm. These examples are provided to illustrate the potential for KLT-IV to be used for quantifying flow rates using videos collected from fixed, or mobile camera systems.

Sources of Chlorophenolic Compounds to the Fraser River Estuary

1988 ◽  
Vol 23 (1) ◽  
pp. 55-68 ◽  
Author(s):  
J. H. Carey ◽  
J. H. Hart
Keyword(s):  
River Flow ◽  
River Estuary ◽  
Low Flow ◽  
Fraser River ◽  
Pulp Mills ◽  
Flow Conditions ◽  
Downstream Site ◽  
Upstream Site ◽  
The North ◽  
Main River

Abstract The identity and concentrations of chlorophenolic compounds in the Fraser River estuary were determined under conditions of high and low river flow at three sites: a site upstream from the trifurcation and at downstream sites for each main river arm. Major chlorophenolics present under both flow regimes were 2,4,6-trichlorophenol (2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP), pentachlorophenol (PCP), tetrachloroguaiacol (TeCG) and a compound tentatively identified as 3,4,5-trichloroguaiacol (3,4,5-TCG). Under high flow conditions, concentrations of the guaiacols were higher than any of the Chlorophenols and concentrations of all five chlorophenolics appeared to correlate. Under low flow conditions, concentrations of chloroguaiacols were higher than Chlorophenols at the upstream site and at the downstream site on the Main Arm, whereas at the downstream site on the North Arm, concentrations of 2,3,4,6-TeCP and PCP were higher than the chloroguaiacols in some samples. Overall, the results indicate that pulp mills upstream from the estuary are important sources of chlorophenolics to the estuary under all flow conditions. Additional episodic inputs of 2,3,4,6-TeCP and PCP from lumber mills occur along the North Arm. When these inputs occur, they can cause the concentrations of Chlorophenols in the North Arm to exceed provisional objectives. If chloroguaiacols are included as part of the objective, concentrations of total chlorophenolics in water entering the estuary can approach and exceed these objectives, especially under low flow conditions.

scholarly journals Soil microbial inoculation during flood events shapes headwater stream microbial communities and diversity

2021 ◽  
Author(s):  
Florian Caillon ◽  
Katharina Besemer ◽  
Peter Peduzzi ◽  
Jakob Schelker
Keyword(s):  
Microbial Diversity ◽  
Bacterial Diversity ◽  
Soil Water ◽  
Headwater Streams ◽  
High Flow ◽  
Low Flow ◽  
Flood Events ◽  
Flow Conditions ◽  
Soil Microbial ◽  
Microbial Inoculation

AbstractFlood events are now recognized as potentially important occasions for the transfer of soil microbes to stream ecosystems. Yet, little is known about these “dynamic pulses of microbial life” for stream bacterial community composition (BCC) and diversity. In this study, we explored the potential alteration of stream BCC by soil inoculation during high flow events in six pre-alpine first order streams and the larger Oberer Seebach. During 1 year, we compared variations of BCC in soil water, stream water and in benthic biofilms at different flow conditions (low to intermediate flows versus high flow). Bacterial diversity was lowest in biofilms, followed by soils and highest in headwater streams and the Oberer Seebach. In headwater streams, bacterial diversity was significantly higher during high flow, as compared to low flow (Shannon diversity: 7.6 versus 7.9 at low versus high flow, respectively, p < 0.001). Approximately 70% of the bacterial operational taxonomic units (OTUs) from streams and stream biofilms were the same as in soil water, while in the latter one third of the OTUs were specific to high flow conditions. These soil high-flow OTUs were also found in streams and biofilms at other times of the year. These results demonstrate the relevance of floods in generating short and reoccurring inoculation events for flowing waters. Moreover, they show that soil microbial inoculation during high flow enhances microbial diversity and shapes fluvial BCC even during low flow. Hence, soil microbial inoculation during floods could act as a previously overlooked driver of microbial diversity in headwater streams.

Exploring probability distribution functions best-fitting the kinetic energy of coarse particles at above threshold flow conditions

2021 ◽  
Author(s):  
Hamed Farhadi ◽  
Manousos Valyrakis
Keyword(s):  
Probability Distribution ◽  
Kinetic Energy ◽  
Test Section ◽  
Particle Transport ◽  
River Flow ◽  
Distribution Functions ◽  
Transport Processes ◽  
Flow Conditions ◽  
Probability Distribution Functions ◽  
Transport Regime

&lt;p&gt;Applying an instrumented particle [1-3], the probability density functions of kinetic energy of a coarse particle (at different solid densities) mobilised over a range of above threshold flow conditions&amp;#160;conditions corresponding to the intermittent transport regime, were explored. The experiments were conducted in the Water Engineering Lab at the University of Glasgow on a tilting recirculating flume with 800 (length) &amp;#215; 90 (width) cm dimension. Twelve different flow conditions corresponding to intermittent transport regime for the range of particle densities examined herein, have been implemented in this research. Ensuring fully developed flow conditions, the start of the test section was located at 3.2 meters upstream of the flume outlet. The bed surface of the flume is flat and made up of well-packed glass beads of 16.2 mm diameter, offering a uniform roughness over which the instrumented particle is transported. MEMS sensors are embedded within the instrumented particle with 3-axis gyroscope and 3-axis accelerometer. At the beginning of each experimental run, instrumented particle is placed at the upstream of the test section, fully exposed to the free stream flow. Its motion is recorded with top and side cameras to enable a deeper understanding of particle transport processes. Using results from sets of instrumented particle transport experiments with varying flow rates and particle densities, the probability distribution functions (PDFs) of the instrumented particles kinetic energy, were generated. The best-fitted PDFs were selected by applying the Kolmogorov-Smirnov test and the results were discussed considering the light of the recent literature of the particle velocity distributions.&lt;/p&gt;&lt;p&gt;[1] Valyrakis, M.; Alexakis, A. Development of a &amp;#8220;smart-pebble&amp;#8221; for tracking sediment transport. In Proceedings of the International Conference on Fluvial Hydraulics (River Flow 2016), St. Louis, MO, USA, 12&amp;#8211;15 July 2016.&lt;/p&gt;&lt;p&gt;[2] Al-Obaidi, K., Xu, Y. &amp; Valyrakis, M. 2020, The Design and Calibration of Instrumented Particles for Assessing Water Infrastructure Hazards, Journal of Sensors and Actuator Networks, vol. 9, no. 3, 36.&lt;/p&gt;&lt;p&gt;[3] Al-Obaidi, K. &amp; Valyrakis, M. 2020, Asensory instrumented particle for environmental monitoring applications: development and calibration, IEEE sensors journal (accepted).&lt;/p&gt;

scholarly journals Spatial and temporal aspects of high streamflow periods within the Danube drainage basin in Bulgaria

2020 ◽  
Vol 11 (1) ◽  
pp. 6-22
Author(s):  
Kalin SEYMENOV ◽  
Keyword(s):  
Drainage Basin ◽  
Threshold Level ◽  
High Flow ◽  
Danube River ◽  
Discharge Data ◽  
Environmental Consequences ◽  
Temporal Aspects ◽  
Daily Discharge ◽  
Spatio Temporal ◽  
Positive Correlations

High flow events are the main prerequisites for floods with negative social and environmental consequences. Their study under uncertain and changing climate gives informative knowledge for further management decisions. This paper seeks to analyze the spatio-temporal parameters of high flow periods within the Danube drainage basin in Bulgaria. Three characteristics of the hazard phenomena: time of occurring, frequency and duration are investigated. The analysis is based on daily discharge data collected from 20 gauging stations for the period 2000–2005. The surplus water quantities are identified by the Threshold level method using fixed values – Q25 and Q5, derived from the flow duration curve. Results show a concentration of the high flow periods during the spring hydrological season, with an average duration up to six weeks. The calculations establish positive correlations between the duration of high flow, the altitude of catchments, and the density of drainage network. The resulting information can serve as a support for the development of preliminary flood risk assessments in the Danube River Basin.

Time-Lapse Monitoring of Daily Velocity Changes in Binchuan, Southwestern China, Using Large-Volume Air-Gun Source Array Data

2022 ◽  
Author(s):  
Yi Luan ◽  
Hongfeng Yang ◽  
Baoshan Wang ◽  
Wei Yang ◽  
Weitao Wang ◽  
...  
Keyword(s):  
Large Volume ◽  
Seismic Data ◽  
Temporal Changes ◽  
Air Pressure ◽  
Southwestern China ◽  
Long Period ◽  
Air Gun ◽  
Velocity Variations ◽  
Velocity Changes ◽  
Source Array

Abstract Temporal changes of seismic velocities in the Earth’s crust can be induced by stress perturbations or material damage from reasons such as strong ground motion, volcanic activities, and atmospheric effects. However, monitoring the temporal changes remains challenging, because most of them generally exist in small travel-time differences of seismic data. Here, we present an excellent case of daily variations of the subsurface structure detected using a large-volume air-gun source array of one-month experiment in Binchuan, Yunnan, southwestern China. The seismic data were recorded by 12 stations within ∼10 km away from the source and used to detect velocity change in the crust using the deconvolution method and sliding window cross-correlation method, which can eliminate the “intercept” error when cutting the air-gun signals and get the real subsurface variations. Furthermore, the multichannel singular spectral analysis method is used to separate the daily change (∼1 cycle per day) from the “long-period” change (&lt;1 cycle per day) or noise. The result suggests that the daily velocity changes at the two nearest stations, 53277 (offset ∼700 m) and 53278 (offset ∼2.3 km), are well correlated with air temperature variation with a time lag of 5.0 ± 1.5 hr, which reflects that the velocity variations at the subsurface are likely attributed to thermoelastic strain. In contrast, both daily and long-period velocity changes at distant stations correlate better with the varying air pressure than the temperature, indicating that the velocity variations at deeper depth are dominated by the elastic loading of air pressure. Our results demonstrate that the air-gun source is a powerful tool to detect the velocity variation of the shallow crust media.

Estimating the hydrodynamic and morphodynamic characteristics using Entropy theory at the confluence of Negro and Solimões Rivers

2021 ◽  
Author(s):  
Farhad Bahmanpouri ◽  
Silvia Barbetta ◽  
Carlo Gualtieri ◽  
Marco Ianniruberto ◽  
Naziano Filizola ◽  
...  
Keyword(s):  
Velocity Distribution ◽  
Flow Characteristics ◽  
Low Flow ◽  
Entropy Theory ◽  
Velocity Data ◽  
Flow Conditions ◽  
Mean Velocity ◽  
Discharge Data ◽  
Confluence Zone ◽  
Error Percentage

&lt;p&gt;When two mega rivers merge the mixing of two flows results in a highly complex three-dimensional flow structure in an area known as the confluence hydrodynamic zone. In the confluence zone, substantial changes occur to the hydrodynamic and morphodynamic features which are of significant interest for researchers. The con&amp;#64258;uence of the Negro and Solim&amp;#245;es Rivers, as one of the largest river junctions on Earth, is the study area of the present research. During the EU-funded Project &amp;#8220;Clim-Amazon&amp;#8221; (2011-2015), velocity data were collected using an ADCP vessel operating under high and low flow conditions in different locations at that confluence (Gualtieri et al., 2019). By applying the Entropy theory developed by Chiu (1988) for natural channels and simplified by Moramarco et al. (2014), the two-dimensional velocity distribution, as well as depth-averaged velocity, were calculated at the different transects along the confluence zone, using only the surface velocities observation. The estimated data yielded 6.6% and 6.9% error percentage for the discharge data related to high and low flow conditions, respectively, and 8.4% and 8.3% error percentage for the velocity data related to high and low flow conditions, respectively. Regardless of the flow condition, these preliminary results also suggest the potential points at the confluence zone for the maximum local scouring. The findings of the current research highlighted the potential of Entropy theory to estimate the flow characteristics at the large river&amp;#8217;s confluence, just starting from the measure of surface velocities. This is of considerable interest for monitoring high flows using&amp;#160;no-contact technology, when ADCP or other contact equipment cannot be used for the safety of operators and risks for equipment loss.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Keywords: Amazon River, Negro/Solim&amp;#245;es Confluence, Entropy Theory, Velocity Distribution, Local Scouring&lt;/p&gt;&lt;p&gt;References&lt;/p&gt;&lt;p&gt;Gualtieri, C., Ianniruberto, M., Filizola, N. (2019). On the mixing of rivers with a difference in density: the case of the Negro/Solim&amp;#245;es confluence, Brazil. Journal of Hydrology, 578(11), November 2019, 124029,&lt;/p&gt;&lt;p&gt;Chiu, C. L. (1988). &amp;#8220;Entropy and 2-D velocity distribution in open channels&amp;#8221;. Journal of Hydrologic Engineering, ASCE, 114(7), 738-756&lt;/p&gt;&lt;p&gt;Moramarco, T., Saltalippi, C., Singh, V.P. (2004). &amp;#8220;Estimation of mean velocity in natural channels based on Chiu&amp;#8217;s velocity distribution equation&amp;#8221;. Journal of Hydrologic Engineering, ASCE, 9 (1), pp. 42-50&lt;/p&gt;

Sign in / Sign up

Export Citation Format

Share Document