El règim tèrmic del tram inferior de l'Ebre i les seues alteracions.

• Autores: Jordi Prats Rodríguez
• Directores de la Tesis: Josep Dolz Ripollès (dir. tes.)
• Lectura: En la Universitat Politècnica de Catalunya (UPC) ( España ) en 2011
• Idioma: catalán
• Tribunal Calificador de la Tesis: Antoni Palau Ibars (presid.), Ernest Bladé Castellet (secret.), Jerónimo Puertas (voc.), Rafael Marcé (voc.), Miguel Angel García Vera (voc.)
• Materias:
  • Ciencias de la vida
    • Biología vegetal (botánica)
      • Limnología
  • Ciencias de la tierra y del espacio
    • Hidrología
      • Aguas superficiales
  • Ciencias tecnológicas
    • Ingeniería y tecnología aeronáuticas
      • Hidrodinámica
• Enlaces
  • Tesis en acceso abierto en: TDX
• Resumen

  • This thesis deals with the study of the thermal regime of the lower Ebro River (Spain), between the towns of Escatrón and Miravet, at different time scales (multiannual, annual, monthly, diel), as well as the alterations caused by the system of reservoirs of Mequinensa, Riba-roja and Flix and by the nuclear power plant of Ascó. The thermal behaviour of the Ebro River in the study area is analysed 1) by examining water temperature and level measurements taken in the river, 2) through the reconstruction of a mean annual water temperature series from historical data, and 3) by means of a numerical model that takes into account the transport processes and heat exchange between water and the environment. Because of its importance for the modelling of the river thermal behaviour, the hydraulic behaviour of the Ebro River downstream from the system of reservoirs has also been studied. Furthermore, owing to its influence on downstream water temperature, special attention has been given to the analysis of the hydrodynamic behaviour of the Riba-roja reservoir, by using the DYRESM model. The study results show an increase in mean annual water temperature at Escatrón of 2.3 ºC in the period 1955-2000. The measurements taken in the study area show a seasonal effect of the system of reservoirs and an increase in water temperature of 3 ºC in mean caused by the nuclear power plant of Ascó. During the spring and summer the alterations produced by the nuclear power plant and the reservoirs are opposed in sign and approximately cancel each other out; during the autumn and winter, both the system of reservoir and the nuclear power plant increase water temperature. In addition, reservoirs induce a decrease in daily thermal variability, while the interaction between the nuclear power plant thermal discharge and hydropeaking caused by reservoirs generates sharp water temperature changes. As water flows downstream its temperature approaches the steady state temperature, though according to modelling results the recuperation distance can be hundreds of kilometres long depending on the intensity of the alteration, river discharge and meteorological state.