Reach-scale suspended sediment balance downstream from dams in a large Mediterranean river |
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| Authors: | A Tena RJ Batalla D Vericat |
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| Institution: | 1. Department of Environment and Soil Sciences , University of Lleida , E-25198 , Lleida , Catalonia , Spain alvaro.tena@macs.udl.cat;3. Department of Environment and Soil Sciences , University of Lleida , E-25198 , Lleida , Catalonia , Spain;4. Forest Technology Centre of Catalonia , E-25280 , Solsona , Catalonia , Spain;5. Catalan Institute for Water Research, H2O Building , E-17003 , Girona , Catalonia , Spain;6. Institute of Geography and Earth Sciences, Aberystwyth University , Ceredigion , SY23 3DB , UK |
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| Abstract: | Abstract This paper presents a reach-scale sediment balance of a large impounded Mediterranean river (the lower Ebro, 1998–2008). Multi-temporal sediment storage and the influence of floods and tributaries on the sediment load were examined using continuous discharge and turbidity records. The mean annual suspended sediment load at the reach outlet (Xerta) is 0.12?×?106 t, corroborating previous results. Suspended sediment concentrations were low (SSCmean?=?13 mg L-1), attaining a maximum of 274 mg L-1. Erosion processes (channel-scour, bank erosion) are dominant, and net export of sediment occurs over the long term. Unexpectedly, ephemeral tributaries were found to contribute significantly: sediment delivered during torrential events attained 5% of the Ebro annual load, and was even larger than that in flushing flows. Overall, most of the suspended sediment load is transported by floods (up to 65% in some years). The results constitute basic information to underpin current management actions aiming to achieve the sustainability of the riverine and deltaic system. Editor D. Koutsoyiannis; Associate editor D. Hughes Citation Tena, A., Batalla, R.J. and Vericat, D., 2012. Reach-scale suspended sediment balance downstream from dams in a large Mediterranean river. Hydrological Sciences Journal, 57 (5), 831–849. |
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| Keywords: | sediment transport dams flow regulation floods sediment storage erosion sedimentation River Ebro |
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