Uncertainty of modelled flow regime for flow-ecological assessment in Southern Europe

Vigiak O, Lutz S, Mentzafou A, Chiogna G, Tuo Y, Majone B, Beck H, de Roo A, Malagó A, Bouraoui F, Kumar R, Samaniego L, Merz R, Gamvroudis C, Skoulikidis N, Nikolaidis NP, Bellin A, Acuňa V, Mori N, Ludwig R, Pistocchi A (2018)

Publication Type: Journal article

Publication year: 2018

Journal

Science of the Total Environment Elsevier

Book Volume: 615

Pages Range: 1028-1047

DOI: 10.1016/j.scitotenv.2017.09.295

Abstract

Sustainable water basin management requires characterization of flow regime in river networks impacted by anthropogenic pressures. Flow regime in ungauged catchments under current, future, or natural conditions can be assessed with hydrological models. Developing hydrological models is, however, resource demanding such that decision makers might revert to models that have been developed for other purposes and are made available to them (‘off-the-shelf’ models). In this study, the impact of epistemic uncertainty of flow regime indicators on flow-ecological assessment was assessed at selected stations with drainage areas ranging from about 400 to almost 90,000 km2 in four South European basins (Adige, Ebro, Evrotas and Sava). For each basin, at least two models were employed. Models differed in structure, data input, spatio-temporal resolution, and calibration strategy, reflecting the variety of conditions and purposes for which they were initially developed. The uncertainty of modelled flow regime was assessed by comparing the modelled hydrologic indicators of magnitude, timing, duration, frequency and rate of change to those obtained from observed flow. The results showed that modelled flow magnitude indicators at medium and high flows were generally reliable, whereas indicators for flow timing, duration, and rate of change were affected by large uncertainties, with correlation coefficients mostly below 0.50. These findings mirror uncertainty in flow regime indicators assessed with other methods, including from measured streamflow. The large indicator uncertainty may significantly affect assessment of ecological status in freshwater systems, particularly in ungauged catchments. Finally, flow-ecological assessments proved very sensitive to reference flow regime (i.e., without anthropogenic pressures). Model simulations could not adequately capture flow regime in the reference sites comprised in this study. The lack of reliable reference conditions may seriously hamper flow-ecological assessments. This study shows the pressing need for improving assessment of natural flow regime at pan-European scale.

Authors with CRIS profile

Gabriele Chiogna

Involved external institutions

European Commission - Joint Research Centre (JRC) NL Netherlands (NL) Helmholtz-Zentrum für Umweltforschung (UFZ) / Helmholtz Center for Environmental Research DE Germany (DE) Hellenic Centre for Marine Research GR Greece (GR) Technische Universität München (TUM) DE Germany (DE) Università degli Studi di Trento IT Italy (IT) Technical University of Crete (TUC) / Πολυτεχνείο Κρήτης GR Greece (GR) National Institute of Biology NIB SI Slovenia (SI) Ludwig-Maximilians-Universität (LMU) DE Germany (DE) Catalan Institute for Water Research / Institut Català de Recerca de l'Aigua (ICRA) ES Spain (ES)

How to cite

APA:

Vigiak, O., Lutz, S., Mentzafou, A., Chiogna, G., Tuo, Y., Majone, B.,... Pistocchi, A. (2018). Uncertainty of modelled flow regime for flow-ecological assessment in Southern Europe. Science of the Total Environment, 615, 1028-1047. https://doi.org/10.1016/j.scitotenv.2017.09.295

MLA:

Vigiak, Olga, et al. "Uncertainty of modelled flow regime for flow-ecological assessment in Southern Europe." Science of the Total Environment 615 (2018): 1028-1047.

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