Channel response to multiple damming in a meandering river, middle and lower Aragón River (Spain)

Small hydropower plants (SHP) affect river flow and sediment transport, and thus, impact river morphology. Eight hydropower schemes were studied along the meandering middle and lower reaches of Aragón River (Spain) to assess their effects on channel morphology and sediment dynamics from 1927 to 2010...

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Detalles Bibliográficos
Autores: Ibisate González de Matauco, Askoa, Díaz Bea, Elena, Ollero, Alfredo, Acín, Vanesa, Granado, David
Tipo de recurso: artículo
Fecha de publicación:2013
País:España
Institución:Universidad del País Vasco
Repositorio:Addi. Archivo Digital para la Docencia y la Investigación
OAI Identifier:oai:addi.ehu.eus:10810/77928
Acceso en línea:http://hdl.handle.net/10810/77928
Access Level:acceso abierto
Palabra clave:Channel adjustment
Human impact
Reservoirs
Weirs
Small hydropower plant
Fluvial geomorphology
Meandering river
Aragón River
Descripción
Sumario:Small hydropower plants (SHP) affect river flow and sediment transport, and thus, impact river morphology. Eight hydropower schemes were studied along the meandering middle and lower reaches of Aragón River (Spain) to assess their effects on channel morphology and sediment dynamics from 1927 to 2010. GIS tools were used to measure changes in fluvial surfaces, channel planform and lateral and vertical dynamics. Three periods (early, middle and late 20th century) were analysed to discern the effects of the main pressures, such as changes in land use, large reservoirs upstream, and SHP. Results were combined with field and topographical measurements and hydrological analysis. Active channel width and channel migration suffered a clear reduction in the whole period. They started as a consequence of land cover changes in the drainage basin, but their speed increased after a large reservoir was built upstream. More recent changes occurred since most of the SHP were put into operation in the 1990's, especially in their short-circuited reaches and in the four more downstream ones. These changes are interpreted as a consequence of reduced discharge, transitory sediment trapping, and reactivation of sediment transport after weirs became filled as well as by the impact of flood hydrology.