Merjenje pretočnih hitrosti in pretokov z Dopplerjevim profilnim merilcem pretočnih hitrosti – primer izbranih hudournikov v Zgornjesavski dolini

Šemrl, Matej (author), Kobal, Milan (mentor)

Na območju občine Kranjska Gora smo na izbranih hudournikih (Martuljek, Mlinca, Pišnica, Sava Dolinka in Triglavska Bistrica) z Dopplerjevim profilnim merilcem pretočnih hitrosti FlowTracker2 opravili meritve hitrosti in pretoka vode. Skupno smo na sedmih merilnih mestih v letih 2020 in 2021 opravili 482 meritev hitrosti vode. Na vsakem merilnem mestu smo pretočni profil razdelili na več vertikal (širina vertikale med 1/2 in 1/20 širine pretočnega profila) in v posameznih vertikalah opravili meritve hitrosti vode na 60 % njene globine. Povprečna izmerjena hitrost vode v posamezni vertikali je znašala 0,717 m/s, najvišja pa 1,881 m/s, najnižja pretočna hitrost vode je znašala 0,300 m/s, najvišja pa 1,153 m/s. Pretok vode smo izračunali po metodi hitrost-površina, vrednosti se gibljejo od 0,113 m3/s do 2,591 m3/s. Relativna napaka meritev pretočne hitrosti vode glede na število vertikal znaša med 0,2 % in 75,1 %, relativna napaka meritve pretoka vode pa med 0,6 % in 58,8 %. Relativna napaka meritev pada z naraščanjem števila vertikal. Potrebno število vertikal za relativno napako meritve pod 5 % je v primeru meritev pretočne hitrosti vode 7,1, v primeru pretoka vode pa 7,8. Maksimalna širina vertikale za relativno napako meritve pod 5 % je v primeru meritev pretočne hitrosti vode 62 cm, v primeru pretoka vode pa 55 cm.

• Language: Slovenian
• Keywords: pretočna hitrost, pretok, Dopplerjev profilni merilec, Zgornjesavska dolina
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: BF - Biotechnical Faculty
• Place of publishing: Ljubljana
• Publisher: [M. Šemrl]
• Year: 2022
• PID: 20.500.12556/RUL-140972
• UDC: 630*3(043.2)=163.6
• COBISS.SI-ID: 122652931
• Publication date in RUL: 22.09.2022

ŠEMRL, Matej, 2022, Merjenje pretočnih hitrosti in pretokov z Dopplerjevim profilnim merilcem pretočnih hitrosti – primer izbranih hudournikov v Zgornjesavski dolini [online]. Bachelor’s thesis. Ljubljana : M. Šemrl. [Accessed 17 May 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=140972

Secondary language

• Language: English
• Title: Measurement of flow velocities and flows using Acoustic Doppler Velocimeter - An example of selected torrents in the Upper Sava Valley

Abstract

In the Municipality of Kranjska Gora, measurements of the speed and flow of water on selected torrents (Martuljek, Mlinca, Pišnica, Sava Dolinka, and Triglavska Bistrica) were performed with the help of the FlowTracker2, the Acoustic Doppler Velocimeter. In 2020 and 2021, 482 water speed measurements at 7 measuring points were carried out in total. At each measuring point, the cross-section of the watercourse was divided into several sections (section width between 1/2 and 1/20 cross-section width) with measurements of water velocity in verticals between sections performed at 60% of water depth. The average measured water velocity in each vertical was 0.717 m/s while the highest was 1.881 m/s. Moreover, the lowest water flow was 0.300 m/s and the highest amounted to 1.153 m/s. The water flow was calculated using the speed-surface method, with values ranging from 0.113 m³/s to 2.591 m³/s. The relative error of the water flow rate relative to the number of verticals is between 0.2% and 75.1%, while the relative error of the water flow measurement ranges between 0.6% and 58.8%. The relative error of the measurements decreases with the increase in the number of sections or verticals. The required number of sections to make the relative measurement error below 5% in the case of water flow rate measurements is 7.1 while it amounts to 7.8 in the case of water flow.

• Keywords: flow velocity, flow, acoustic Doppler velocimeter, Upper Sava Valley, torrents