Streamflow Recession Analysis Using Water Height

In the frame of a technological research and innovation network in water and environment technologies (RITEAU, Réseau de Recherche et d'Innovation Technologique Eau et Environnement), our research group, in collaboration with industrial partners and other research institutions, has been in charge of the development of a suitable flowmeter: an ultrasonic device measuring simultaneously the water flow and the concentration of size classes of suspended particles. Working on the pulsed ultrasound principle, our multi-frequency device (1 to 14 MHz) allows flow velocity and water height measurement and estimation of suspended solids concentration. Velocity measurements rely on the coherent Doppler principle. A self developed frequency estimator, so called Spectral Identification method, was used and compared to the classical Pulse-Pair method. Several measurements campaigns on one wastewater collector of the French city of Strasbourg gave very satisfactory results and showed smaller standard deviation values for the Doppler frequency extracted by the Spectral Identification method. A specific algorithm was also developed for the water height measurements. It relies on the water surface acoustic impedance rupture and its peak localisation and behaviour in the collected backscattering data. This algorithm was positively tested on long time measurements on the same wastewater collector. A large part of the article is devoted to the measurements of the suspended solids concentrations. Our data analysis consists in the adaptation of the well described acoustic behaviour of sand to the behaviour of wastewater particles. Both acoustic attenuation and acoustic backscattering data over multiple frequencies are analyzed for the extrapolation of size classes and respective concentrations. Under dry weather conditions, the massic backscattering coefficient and the overall size distribution showed similar evolution whatever the measurement site was and were suggesting a global wastewater particles behaviour. By comparison to sampling data, our data analysis lead to the characterization of two particle groups: the ones occurring during rain events and the ones typical of wastewater under dry weather conditions. Even with already encouraging results on the several weeks of data recorded on several wastewater collectors, the validation of our data inversion method is still under progress.

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Power Generation and Oxygen Transfer Analyses for Micro Hydro-Turbine Installed in Wastewater Treatment Aeration Tank

Journal of Energy Resources Technology ◽

10.1115/1.4052538 ◽

2021 ◽

pp. 1-16

Author(s):

Abdel Rahman Salem ◽

Alaa Hasan ◽

Ahmad Abdelhadi ◽

Saif Al Hamad ◽

Mohammad Qandil ◽

...

Keyword(s):

Wastewater Treatment ◽

Oxygen Transfer ◽

Power Loss ◽

Wastewater Treatment Plants ◽

Aeration Tank ◽

Hydro Turbine ◽

Oxygen Transfer Efficiency ◽

Aeration Process ◽

The U.S ◽

Water Height

Abstract This study targets one of the major energy consumers in the U.S. It suggests a new mechanical system that can recover a portion of the energy in Wastewater Treatment Plants (WWTPs). The proposed system entails a hydro-turbine installed above the air diffuser in the aeration tank to extract the water-bubble current's kinetic energy and converts it to electricity. Observing the optimum location of the turbine required multiple experiments where turbine height varies between 35% and 95% (water height percentages above the diffuser), while varying the airflow between 1.42 L/s (3 CFM) and 2.12 L/s (4.5 CFM) with a 0.24 L/s (0.5 CFM) increment. Additionally, three water heights of 38.1 cm (15”), 53.4 cm (21”), and 68.6 cm (27”) were considered to study the influence of the water height. It was noticed that the presence of the system has an adverse effect on the Standard Oxygen Transfer Efficiency (SOTE). Therefore, a small dual-blade propeller was installed right above the diffuser to directly mix the water in the bottom of the tank with the incoming air to enhance the SOTE. The results showed that the maximum reclaimed power was obtained where the hydro-turbine is installed at 65% - 80% above the diffuser. A reduction of up to 7.32% in SOTE was observed when the setup was placed inside the tank compared to the tank alone. The addition of the dual-blade propeller showed an increase in SOTE of 7.27% with a power loss of 6.21%, ensuring the aeration process was at its standards.

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Study of aircore phenomenon and influence of water height during liquid draining

Journal of Mechanical Science and Technology ◽

10.1007/s12206-017-0727-7 ◽

2017 ◽

Vol 31 (8) ◽

pp. 3831-3837 ◽

Cited By ~ 2

Author(s):

Kamran Nazir ◽

Chang Hyun Sohn

Keyword(s):

Influence Of Water ◽

Water Height

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Are streamflow recession characteristics really characteristic?

Hydrology and Earth System Sciences ◽

10.5194/hess-17-817-2013 ◽

2013 ◽

Vol 17 (2) ◽

pp. 817-828 ◽

Cited By ~ 57

Author(s):

M. Stoelzle ◽

K. Stahl ◽

M. Weiler

Keyword(s):

Extraction Method ◽

Storage Capacity ◽

Extraction Methods ◽

Model Parameters ◽

Catchment Scale ◽

Model Parameterization ◽

Recession Curves ◽

Recession Analysis ◽

Meso Scale

Abstract. Streamflow recession has been investigated by a variety of methods, often involving the fit of a model to empirical recession plots to parameterize a non-linear storage–outflow relationship based on the dQ/dt−Q method. Such recession analysis methods (RAMs) are used to estimate hydraulic conductivity, storage capacity, or aquifer thickness and to model streamflow recession curves for regionalization and prediction at the catchment scale. Numerous RAMs have been published, but little is known about how comparably the resulting recession models distinguish characteristic catchment behavior. In this study we combined three established recession extraction methods with three different parameter-fitting methods to the power-law storage–outflow model to compare the range of recession characteristics that result from the application of these different RAMs. Resulting recession characteristics including recession time and corresponding storage depletion were evaluated for 20 meso-scale catchments in Germany. We found plausible ranges for model parameterization; however, calculated recession characteristics varied over two orders of magnitude. While recession characteristics of the 20 catchments derived with the different methods correlate strongly, particularly for the RAMs that use the same extraction method, not all rank the catchments consistently, and the differences among some of the methods are larger than among the catchments. To elucidate this variability we discuss the ambiguous roles of recession extraction procedures and the parameterization of the storage–outflow model and the limitations of the presented recession plots. The results suggest strong limitations to the comparability of recession characteristics derived with different methods, not only in the model parameters but also in the relative characterization of different catchments. A multiple-methods approach to investigating streamflow recession characteristics should be considered for applications whenever possible.

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Absolute Calibration or Validation of the Altimeters on the Sentinel-3A and the Jason-3 over Lake Issykkul (Kyrgyzstan)

Remote Sensing ◽

10.3390/rs10111679 ◽

2018 ◽

Vol 10 (11) ◽

pp. 1679 ◽

Cited By ~ 11

Author(s):

Jean-François Crétaux ◽

Muriel Bergé-Nguyen ◽

Stephane Calmant ◽

Nurzat Jamangulova ◽

Rysbek Satylkanov ◽

...

Keyword(s):

Satellite System ◽

Reference Points ◽

Absolute Calibration ◽

In Situ Data ◽

Absolute Bias ◽

Weather Stations ◽

Field Campaigns ◽

The Absolute ◽

Gps System ◽

Water Height

Calibration/Validation (C/V) studies using sites in the oceans have a long history and protocols are well established. Over lakes, C/V allows addressing problems such as the performance of the various retracking algorithms and evaluating the accuracy of the geophysical corrections for continental waters. This is achievable when measurements of specific and numerous field campaigns and a ground permanent network of level gauges and weather stations are processed. C/V consists of installation of permanent sites (weather stations, limnigraphs, and GPS reference points) and the organization of regular field campaigns. The lake Issykkul serves as permanent site of C/V, for a multi-mission purpose. The objective of this paper is to calculate the altimeter biases of Jason-3 and Sentinel-3A, both belonging to an operational satellite system which is used for the long-term monitoring of lake level variations. We have also determined the accuracy of the altimeters of these two satellites, through a comparison analysis with in situ data. In 2016 and 2017, three campaigns have been organized over this lake in order to estimate the absolute bias of the nadir altimeter onboard the Jason-3 and Sentinel-3A. The fieldwork consisted of measuring water height using a GPS system, carried on a boat, along the track of the altimeter satellite across the lake. It was performed at the time of the pass of the altimeter. Absolute altimeter biases were calculated by averaging the water height differences along the pass of the satellite (GPS from the boat system versus altimetry). Jason-3 operates in a Low Resolution Mode (LRM), while the Sentinel-3A operates in Synthetic Aperture Radar (SAR) mode. In this study we found that the absolute biases measured for Jason-3 were −28 ± 40 mm with the Ocean retracker and 206 ± 30 mm with the Ice-1 retracker. The biases for Sentinel-3A were −14 ± 20 mm with the Samosa (Ocean like) retracker and 285 ± 20 mm with the OCOG (Ice-1-like) retracker. We have also evaluated the accuracy of these two altimeters over Lake Issykkul which reached to 3 cm, for both the instruments, using the Ocean retracker.

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REVIEW of the paper, “Recession analysis 42 years later -work yet to be done” (Jachens et al.)

10.5194/hess-2019-205-rc2 ◽

2019 ◽

Author(s):

Anonymous

Keyword(s):

Recession Analysis

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HARBOUR DESIGN INCLUDING SEDIMENTOLOGICAL PROBLEMS USING MAINLY NUMERICAL TECHNICS

Coastal Engineering Proceedings ◽

10.9753/icce.v17.132 ◽

1980 ◽

Vol 1 (17) ◽

pp. 132 ◽

Cited By ~ 1

Author(s):

B. Latteux

Keyword(s):

Continuity Equation ◽

Numerical Study ◽

Numerical Models ◽

Near Field ◽

Step Method ◽

Access Channel ◽

Load Transport ◽

Erosion Area ◽

Bed Load Transport ◽

Water Height

For most of the needed studies for the design of Calais harbour enlargement works, the "Laooratoire National d'Hydraulique" chose to use numerical models. This approach includes the determination of currents around and insiae the new outer-haroour, just as the evaluation of the project sedimentologic impact and of the long-term evolution of a bank nameo "le Riaen de ia Rade", edging the access channel. Current studies were performed using four nested bidimensionnal computer models fitted on field data and supplying in eac;i point the depth-averaged velocity and the total water height. These four models are based on an implicite finite difference fractionnal step method. Besides for the very near field model the method is especially elaborated to enable' the detailed reproduction of eddies and flow separations. The sedimentological numerical study is based upon current models results : the bed-load transport is computed from the depth-averaged velocity and the water height previously determined using an empirical formula, and tne continuity equation applied to this loaa transport gives then the bed evolution. As soon as the depth variation is significant enough to react on the flow pattern, current fielos are readjusted oy a simple metnod based on flow continuity equation. This numerical model, applied to the near fielo, has given an evaluation of the sedimentological impact of the haroour enlargement project : - strong erosion in front of the new harbour due to current strengthening ; - accretion on each side of this erosion area, especially in the channel ; - bar formation at the harbour entrance.

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