| Title | Classifying the flow regimes of Mediterranean streams using multivariate analysis |
| Abstract | Rivers in the Mediterranean region often exhibit an intermittent character. An understanding and classification of the flow
regimes of these rivers is needed, as flow patterns control both physicochemical and biological processes. This paper reports an
attempt to classify flow regimes in Mediterranean rivers based on hydrological variables extracted from discharge time series.
Long-term discharge records from 60 rivers within the Mediterranean region were analysed in order to classify the streams into
different flow regime groups. Hydrological indices (HIs) were derived for each stream and principal component analysis (PCA)
and then applied to these indices to identify subsets of HIs describing the major sources of variations, while simultaneously
minimizing redundancy. PCA was performed for two groups of streams (perennial and temporary) and for all streams combined.
The results show that whereas perennial streams are mainly described by high-flow indices, temporary streams are described by
duration, variability and predictability indices. Agglomerative cluster analysis based on HIs identified six groups of rivers
classified according to differences in intermittency and variability. A methodology allowing such a classification for ungauged
catchments was also tested. Broad-scale catchment characteristics based on digital elevation, climate, soil and land use data were
derived for each long-term station where these data were available. By using stepwise multiple regression analysis, statistically
significant relationships were fitted, linking the three selected hydrological variables (mean annual number of zero-flow days,
predictability and flashiness) to the catchment characteristics. The method provides a means of simplifying the complexity of
river systems and is thus useful for river basin management. |
| Source | Hydrological processes (Print) 29, pp. 4666–4682 |
| Keywords | Flow regimeMediterranean rivershydrological variablesPrincipal component analysiscluster analysisregression modelling |
| Journal | Hydrological processes (Print) |
| Editor | Wiley,, Chichester, Sussex, England, Regno Unito |
| Year | 2015 |
| Type | Articolo in rivista |
| DOI | 10.1002/hyp.10530 |
| Authors | Ons Oueslati, Anna Maria De Girolamo, Aziz Abouabdillah, Thomas R. Kjeldsen and Antonio Lo Porto1 |
| Text | 331560 2015 10.1002/hyp.10530 ISI Web of Science WOS WOS 000363277400002 Scopus 2 s2.0 84945489770 Flow regime Mediterranean rivers hydrological variables Principal component analysis cluster analysis regression modelling Classifying the flow regimes of Mediterranean streams using multivariate analysis Ons Oueslati, Anna Maria De Girolamo, Aziz Abouabdillah, Thomas R. Kjeldsen and Antonio Lo Porto1 1 Water Research Institute, National Research Council, Bari, Italy 2 Department of Agronomy, National School of Agriculture of Meknes, Meknes, Morocco 3 Department of Architecture and Civil Engineering, University of Bath, Bath, UK Rivers in the Mediterranean region often exhibit an intermittent character. An understanding and classification of the flow regimes of these rivers is needed, as flow patterns control both physicochemical and biological processes. This paper reports an attempt to classify flow regimes in Mediterranean rivers based on hydrological variables extracted from discharge time series. Long term discharge records from 60 rivers within the Mediterranean region were analysed in order to classify the streams into different flow regime groups. Hydrological indices HIs were derived for each stream and principal component analysis PCA and then applied to these indices to identify subsets of HIs describing the major sources of variations, while simultaneously minimizing redundancy. PCA was performed for two groups of streams perennial and temporary and for all streams combined. The results show that whereas perennial streams are mainly described by high flow indices, temporary streams are described by duration, variability and predictability indices. Agglomerative cluster analysis based on HIs identified six groups of rivers classified according to differences in intermittency and variability. A methodology allowing such a classification for ungauged catchments was also tested. Broad scale catchment characteristics based on digital elevation, climate, soil and land use data were derived for each long term station where these data were available. By using stepwise multiple regression analysis, statistically significant relationships were fitted, linking the three selected hydrological variables mean annual number of zero flow days, predictability and flashiness to the catchment characteristics. The method provides a means of simplifying the complexity of river systems and is thus useful for river basin management. 29 Published version Classifying the flow regimes of Mediterranean streams using multivariate analysis 10_1002_hyp_10530.pdf Articolo in rivista Wiley, 0885 6087 Hydrological processes Print Hydrological processes Print Hydrol. process. Print Hydrological processes. Print OUESLATI ONS antonio.loporto LO PORTO ANTONIO annamaria.degirolamo DE GIROLAMO ANNA MARIA MIRAGE Mediterranean Intermittent River Management TA.P04.005.006 Gestione a scala di bacino delle risorse idriche e sostenibilita dell uso irriguo in agricoltura |
