ETD

Archivio digitale delle tesi discusse presso l'Università di Pisa

Tesi etd-05252012-055938


Tipo di tesi
Tesi di laurea specialistica
Autore
LEONARDI, NICOLETTA
URN
etd-05252012-055938
Titolo
River mouth bars growth in deltaic environment: the role of tides
Dipartimento
INGEGNERIA
Corso di studi
INGEGNERIA IDRAULICA, DEI TRASPORTI E DEL TERRITORIO
Relatori
relatore Prof. Fagherazzi, Sergio
relatore Prof. Pagliara, Stefano
Parole chiave
  • Delta
  • river mouth
  • bars
  • tide
Data inizio appello
03/07/2012
Consultabilità
Non consultabile
Data di rilascio
03/07/2052
Riassunto
River mouths may be considered as the most fundamental elements of deltaic system and the depositional morphologies and the sedimentary sequences of river-mouth systems are among the most varied of all coastal accumulation forms [Wright, L. D. (1977)]. Moreover, they are vulnerable to both anthropogenic and natural changes, such as global environmental change, near shore processes, sea level rise and changes in sediment supply. The economical and ecological importance of river mouths has fostered the interest of many researcher toward these highly dynamic environment. Particularly, many studies have been concentrating on the deposition that takes place at these points and that contributes to delta progradation. Despite certain commonalities, river mouths and their associated deposits exhibit a wide variety of planar configurations and internal forms, reflecting different mechanisms and patterns of outflow dispersion. As a matter of fact, external drivers might play a considerable role in the depositional processes. Among the others, relevant external drivers are the tidal range, the degree to which tidal currents dominate within the lower river channel, and the strengths of the waves [Wright, L. D. and J. M. Coleman (1974)]. This work aims at analyzing the effect of tides on the river mouth bars evolution. The investigation is limited to one geometry and homopycnal effluents (i.e with negligible buoyancy); wind waves and Coriolis forces are also neglected. Moreover two extreme cases have been taken into account: the case one is the theoretical condition of a river with negligible tidal prism and mono-directional flow, on the other hand, the case two is characterized by a not negligible tidal prism, a relative small river discharge and, as a consequence, a bi-directional flow. The modeling system applied is Delft3D, which is described in detail in Lesser et al. (2004). Delft3D is an integrated computer software suite for a multi-disciplinary approach and computations for coastal, river and estuarine areas.
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