| Title | Classifying low flow hydrological regimes at a regional scale |
| Abstract | The paper uses a simple water balance model that partitions the precipitation between actual evapotranspiration, quick flow and delayed flow, and has sufficient complexity to capture the essence of climate and vegetation controls on this partitioning. Using this model, monthly flow duration curves have been constructed from climate data across Europe to address the relative frequency of ecologically critical low flow stages in semi-arid rivers, when flow commonly persists only in disconnected pools in the river bed. The hydrological model is based on a dynamic partitioning of precipitation to estimate water available for evapotranspiration and plant growth and for residual runoff. The duration curve for monthly flows has then been analysed to give an estimate of bankfull flow based on recurrence interval. Arguing from observed ratios of cross-sectional areas at flood and low flows, hydraulic geometry suggests that disconnected flow under "pool" conditions is approximately 0.1 % of bankfull flow. Flow duration curves define a measure of bankfull discharge on the basis of frequency. The corresponding frequency for pools is then read from the duration curve, using this (0.1 %) ratio to estimate pool discharge from bank full discharge. The flow duration curve then provides an estimate of the frequency of poorly connected pool conditions, corresponding to this discharge, that constrain survival of river-dwelling arthropods and fish. The methodology has here been applied across Europe at 15 km resolution, and the potential is demonstrated for applying the methodology under alternative climatic scenarios. |
| Source | Hydrology and earth system sciences 15, pp. 3741–3750 |
| Keywords | River management; low flow; duration curves |
| Journal | Hydrology and earth system sciences |
| Editor | Copernicus Publ., Göttingen, Germania |
| Year | 2011 |
| Type | Articolo in rivista |
| DOI | 10.5194/hess-15-3741-2011 |
| Authors | Kirkby M.J., Gallart F., Kjeldsen T.R., Irvine B.J., Froebrich J., Lo Porto A., De Girolamo A. |
| Text | 42456 2011 10.5194/hess 15 3741 2011 River management; low flow; duration curves Classifying low flow hydrological regimes at a regional scale Kirkby M.J., Gallart F., Kjeldsen T.R., Irvine B.J., Froebrich J., Lo Porto A., De Girolamo A. School of Geography, University of Leeds, UK Surface Hydrology and Erosion Group, Geosciences Department Institute of Environmental Assessment and Water Research IDÆA , CSIC Barcelona, Spain Centre for Ecology Hydrology CEH , Wallingford, UK Centre for Water and Climate CWK , Integrated Water Resources Management, Alterra, Wageningen, The Netherlands Water Research Institute IRSA CNR, Bari, Italy The paper uses a simple water balance model that partitions the precipitation between actual evapotranspiration, quick flow and delayed flow, and has sufficient complexity to capture the essence of climate and vegetation controls on this partitioning. Using this model, monthly flow duration curves have been constructed from climate data across Europe to address the relative frequency of ecologically critical low flow stages in semi arid rivers, when flow commonly persists only in disconnected pools in the river bed. The hydrological model is based on a dynamic partitioning of precipitation to estimate water available for evapotranspiration and plant growth and for residual runoff. The duration curve for monthly flows has then been analysed to give an estimate of bankfull flow based on recurrence interval. Arguing from observed ratios of cross sectional areas at flood and low flows, hydraulic geometry suggests that disconnected flow under pool conditions is approximately 0.1 % of bankfull flow. Flow duration curves define a measure of bankfull discharge on the basis of frequency. The corresponding frequency for pools is then read from the duration curve, using this 0.1 % ratio to estimate pool discharge from bank full discharge. The flow duration curve then provides an estimate of the frequency of poorly connected pool conditions, corresponding to this discharge, that constrain survival of river dwelling arthropods and fish. The methodology has here been applied across Europe at 15 km resolution, and the potential is demonstrated for applying the methodology under alternative climatic scenarios. 15 Published version Articolo in rivista Copernicus Publ. 1027 5606 Hydrology and earth system sciences Hydrology and earth system sciences Hydrol. earth syst. sci. Hydrology and earth system sciences. HESS Gottingen. Print Hydrology and earth system sciences Print 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 |
