Applicability of Bowen ratio energy balance method in fetch limited conditions

0390331 - ÚVGZ 2013 RIV CZ eng K - Konferenční příspěvek (tuzemská konf.)
Pozníková, G. - Trnka, Miroslav - Fischer, Milan - Orság, Matěj - Žalud, Zdeněk
Applicability of Bowen ratio energy balance method in fetch limited conditions.
MendelNet 2012 - Proceedings of International Ph.D. Students Conference. Brno: Mendelova univerzita v Brně, 2012, s. 493-503. ISBN 978-80-7375-656-7.
[MendelNet 2012. Brno (CZ), 21.11.2012-22.11.2012]
Grant CEP: GA MŠMT(CZ) EE2.3.20.0248
Institucionální podpora: RVO:67179843
Klíčová slova: evapotranspiration * Bowen ratio energy balance method * limited fetch
Kód oboru RIV: EH - Ekologie - společenstva

Water plays a key role in the climatic processes of the Earth. In terrestrial ecosystems the main component of water loss is evapotranspiration. One of the standard techniques used to measure evapotranspiration indirectly is the Bowen ratio energy balance method (BREB). This study focuses on the quantification of errors caused by insufficient fetch (upwind distance from the edge of investigated cover) using data from two BREB systems obtained through intensive summer 2012 campaign. The measurement took advantage of one mobile and one fixedly positioned BREB systems employed at turf grass cover from the prevailing north-west wind direction surrounded by broadleaved trees, poplar stoolbed dirty road and buildings at experimental station in Domanínek near Bystřice nad Pernštejnem. Surprisingly, the results showed no significant systematic deviation between the reference BREB with sufficient 180 m long fetch and mobile BREB positioned at fetches between 10 to 100 m. Moreover, it was not found any impact of the fetch on non-systematic errors leading to the conclusion that the fetch did not have any effect on the overall data quality and consistency. One of the explanations may be very similar response to soil moisture conditions of the selected contrasting living ecosystems and thus their similar Bowen ratios.
Trvalý link: http://hdl.handle.net/11104/0219210