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| Titel |
Hydrometry's classical and Innovative methods and tools comparison for Stara river flows at Agios Germanos monitoring station in north-west Greece. |
| VerfasserIn |
Agathos Filintas, Evagellos Hatzigiannakis, George Arampatzis, Andreas Ilias, Andreas Panagopoulos, Ioannis Hatzispiroglou |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250113405
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| Publikation (Nr.) |
 EGU/EGU2015-13601.pdf |
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| Zusammenfassung |
| Abstract
The aim of the present study is a thorough comparison of hydrometry’s conventional and innovative methods-tools for river flow monitoring. A case study was conducted in Stara river at Agios Germanos monitoring station (northwest Greece), in order to investigate possible deviations between conventional and innovative methods-tools on river flow velocity and discharge. For this study, two flowmeters were used, which manufac-tured in 2013 (OTT Messtechnik Gmbh, 2013), as follows:
a) A conventional propeller flow velocity meter (OTT-Model C2) which is a me-chanical current flow meter with a certification of calibration BARGO, operated with a rod and a relocating device, along with a digital measuring device including an elec-tronic flow calculator, data logger and real time control display unit. The flowmeter has a measurement velocity range 0.025-4.000 m/s.
b) An innovative electromagnetic flowmeter (OTT-Model MF pro) which it is con-sisted of a compact and light-weight sensor and a robust handheld unit. Both system components are designed to be attached to conventional wading rods. The electromag-netic flowmeter uses Faraday's Law of electromagnetic induction to measure the process flow. When an electrically conductive fluid flows along the meter, an electrode voltage is induced between a pair of electrodes placed at right angles to the direction of mag-netic field. The electrode voltage is directly proportional to the average fluid velocity. The electromagnetic flowmeter was operated with a rod and relocating device, along with a digital measuring device with various logging and graphical capabilities and vari-ous methods of velocity measurement (ISO/USGS standards). The flowmeter has a measurement velocity range 0.000-6.000 m/s.
The river flow data were averaged over a pair measurement of 60+60 seconds and the measured river water flow velocity, depths and widths of the segments were used for the estimation of cross-section’s mean flow velocity in each measured segment. Then it was used the mid-section method for the overall discharge calculation of all segments flow area. The cross-section characteristics, the river flow velocity of segments and the mean water flow velocity and discharge total profile were measured, calculated and an-notated respectively. A series of concurrent conventional and innovative (electromag-netic) flow measurements were performed during 2014.
The results and statistical analysis showed that Froude number during the measurement period in all cases was Fr<1 which means that the water flow of the Stara river is classified as subcritical flow. The 12 months’ study showed various advantages for the elec-tromagnetic sensor that is virtually maintenance-free because there are no moving parts, no calibration was required in practice, and it can be used even in the lowest water ve-locities from 0.000 m/s.
Moreover, based on the concurrent hydromeasurements of the Stara River, on the velocity and discharge modelling and the statistical analysis, it was found that there was not a significant statistical difference (α=0.05) between mean velocity measured with a) conventional and b) electromagnetic method which seems to be more accurate in low velocities where a significant statistical difference was found.
Acknowledgments
Data in this study are collected in the framework of the elaboration of the national water resources monitoring network, supervised by the Special Secretariat for Water–Hellenic Ministry for the Environment and Climate Change. This project is elaborated in the framework of the operational program “Environment and Sustainable Development” which is co-funded by the National Strategic Reference Framework (NSRF) and the Public Investment Program (PIP). |
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