Characterizing temporary hydrological regimes at a European scale
1School of Geography, University of Leeds, Leeds, UK
2Surface Hydrology and Erosion Group, Geosciences Department, Institute of Environmental Assessment and Water Research (IDÆA), CSIC, Barcelona, Spain
3Centre for Ecology and Hydrology (CEH), Wallingford, UK
4Centre for Water and Climate (CWK), Integrated Water Resources Management, Alterra, Wageningen, The Netherlands
5Water Research Institute IRSA-CNR, Bari, Italy
*MIRAGE project (Mediterranean Intermittent River ManAGEment): 7th EU Framework Programme, coordinated by J. Froebrich, Centre for Water and Climate (CWK), Integrated Water Resources Management, Alterra, Wageningen, The Netherlands
Abstract. Monthly duration curves have been constructed from climate data across Europe to help address the relative frequency of ecologically critical low flow stages in temporary rivers, when flow persists only in disconnected pools in the river bed. The hydrological model is based on a 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. The corresponding frequency for pools is then based on the ratio of bank full discharge to pool flow, arguing from observed ratios of cross-sectional areas at flood and low flows to estimate pool flow as 0.1% of bankfull flow, and so estimate the frequency of the pool conditions that constrain survival of river-dwelling arthropods and fish. The methodology has been applied across Europe at 15 km resolution, and can equally be applied under future climatic scenarios.