Technical gazette, Vol. 22 No. 5, 2015.
Preliminary communication
https://doi.org/10.17559/TV-20140811003920
Indicators of sub-daily hydrological alterations
Darko Barbalić
; Hrvatske vode, Zavod za vodno gospodarstvo, Ulica grada Vukovara 220, 10 000 Zagreb, Croatia
Neven Kuspilić
; Građevinski fakultet Sveučilišta u Zagrebu, Kačićeva 26, 10 000 Zagreb, Croatia
Abstract
Ecological status, according to EU Water Framework Directive, is an expression of the quality of the structure and functioning of aquatic ecosystems associated with surface waters. It can be compromised by different forms of hydrological alterations. In this paper some aspects of fast and frequent fluctuations of discharge, most often caused by production of electric energy to meet peek demands or so called "hydro-peaking" has been studied. Two "hydro-peaking" indicators defined in CEN guidance standard have been evaluated for the undisturbed gauging stations in the Danube River basin in Croatia and correlated to watershed size descriptors and fitting Indicators of Hydrological Alterations. Additional third indicator based on discharge, analogous to indicator from CEN, was introduced and studied in the same way. Results have revealed that on majority of examined gauging stations values of indicators exceed boundaries for "near-natural" and "slightly modified" state. It appears that the use of analogous discharge based indicator instead of level based indicator has some advantages such as easier application and potential for more reliable regionalisation. Reliability of relationship of the third hydro-peaking indicator, based on hourly flow data, to Indicators of Hydrological Alterations, based on daily flow data, indicates the possibility of using significantly larger pool of daily data for definition of reference (undisturbed) conditions for sub-daily flow variations.
Keywords
Danube River basin; hydromorphology; hydro-peaking; Indicators of Hydrological Alterations
Hrčak ID:
147306
URI
Publication date:
22.10.2015.
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