Uncertainty of modelled flow regime for flow-ecological assessment in Southern Europe
| Autor: | Angeliki Mentzafou, Ralf Merz, Alberto Pistocchi, Fayçal Bouraoui, Nikolaos Skoulikidis, Ad de Roo, Stefanie Lutz, Rohini Kumar, Ralf Ludwig, Gabriele Chiogna, Alberto Bellin, C. Gamvroudis, Bruno Majone, Luis Samaniego, Olga Vigiak, Nikolaos P. Nikolaidis, Vicenç Acuňa, Hylke E. Beck, Ye Tuo, Anna Malagó, Nataša Mori |
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| Rok vydání: | 2018 |
| Předmět: |
Environmental Engineering
Ecohydrological assessment 0208 environmental biotechnology Flow (psychology) Drainage basin 02 engineering and technology Structural basin Streamflow Lisflood Environmental Chemistry SWAT Uncertainty quantification Drainage HYPERstream Waste Management and Disposal Hydrology geography geography.geographical_feature_category Flow regime mHM Pollution Ecological assessment 6. Clean water 020801 environmental engineering ddc Current (stream) 13. Climate action Environmental science |
| Popis: | Summarization: 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 km 2 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. Presented on |
| Databáze: | OpenAIRE |
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