Rainfall simulators - innovations seeking rainfall uniformity and automatic flow rate measurements

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F16%3A00305077" target="_blank" >RIV/68407700:21110/16:00305077 - isvavai.cz</a>

Výsledek na webu

<a href="http://meetingorganizer.copernicus.org/EGU2016/EGU2016-936.pdf" target="_blank" >http://meetingorganizer.copernicus.org/EGU2016/EGU2016-936.pdf</a>

DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Rainfall simulators - innovations seeking rainfall uniformity and automatic flow rate measurements

Popis výsledku v původním jazyce

Field rainfall simulators are used worldwide for many experimental purposes, such as runoff generation and soil erosion research. At CTU in Prague a laboratory simulator with winging nozzles VeeJet has been operated since 2001. Since 2012 a terrain simulator is being used with 4 fixed FullJet 40WSQ nozzles with 2,4 m spacing over two simultaneously experimental plots sizing 8x2 and 1x1 m. In parallel activities a specific problem was solved: improving rainfall spatial uniformity and overall intensity and surface runoff measurements. Although the original nozzles setting produced (commonly used) Christiansen uniformity index CU over 80 %, detailed measurements proved this index insufficient and showed many unrequired rainfall extremes within the plot. Moreover the number of rainfall intensity scenarios was limited and some of them required problematic multi-pressure operation of the water distribution system. Whole experimental plot 10x2 m is better covered with the rainfall while the water consumption is retained. Nozzles are triggered in triplets, which enables more rainfall intensity scenarios. Water distribution system is more stable due to single pressure operating mode, which is ensured by the pressure probe controlled electromagnetic valve. Previous experiments implied the need of automatic continuous measurements of selected variables. To this end the control unit was equipped with a datalogger. In a several seconds time step it collects the values of water pressure, nozzle-valves operation, control point rainfall intensity from a tipping bucket rain gauge, topsoil moisture from several Theta ML2x probes and most recently the plot outlet runoff rate. For a continuous runoff rate measurement a 0,4-foot HS-flume was constructed and equipped with S18U ultrasonic sensor. Assemble setting was optimised both in flow rate laboratory flume and in laboratory rainfall simulator. Namely the rating curves for particular flume bottom slopes were derived.

Název v anglickém jazyce

Rainfall simulators - innovations seeking rainfall uniformity and automatic flow rate measurements

Popis výsledku anglicky

Field rainfall simulators are used worldwide for many experimental purposes, such as runoff generation and soil erosion research. At CTU in Prague a laboratory simulator with winging nozzles VeeJet has been operated since 2001. Since 2012 a terrain simulator is being used with 4 fixed FullJet 40WSQ nozzles with 2,4 m spacing over two simultaneously experimental plots sizing 8x2 and 1x1 m. In parallel activities a specific problem was solved: improving rainfall spatial uniformity and overall intensity and surface runoff measurements. Although the original nozzles setting produced (commonly used) Christiansen uniformity index CU over 80 %, detailed measurements proved this index insufficient and showed many unrequired rainfall extremes within the plot. Moreover the number of rainfall intensity scenarios was limited and some of them required problematic multi-pressure operation of the water distribution system. Whole experimental plot 10x2 m is better covered with the rainfall while the water consumption is retained. Nozzles are triggered in triplets, which enables more rainfall intensity scenarios. Water distribution system is more stable due to single pressure operating mode, which is ensured by the pressure probe controlled electromagnetic valve. Previous experiments implied the need of automatic continuous measurements of selected variables. To this end the control unit was equipped with a datalogger. In a several seconds time step it collects the values of water pressure, nozzle-valves operation, control point rainfall intensity from a tipping bucket rain gauge, topsoil moisture from several Theta ML2x probes and most recently the plot outlet runoff rate. For a continuous runoff rate measurement a 0,4-foot HS-flume was constructed and equipped with S18U ultrasonic sensor. Assemble setting was optimised both in flow rate laboratory flume and in laboratory rainfall simulator. Namely the rating curves for particular flume bottom slopes were derived.

Druh

O - Ostatní výsledky

CEP obor

DA - Hydrologie a limnologie

OECD FORD obor

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Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2016

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů