Reconstructing the plurisecular trajectory of an exemplary hybrid urban delta (Tarragona-Francolí system, Spain): Towards the end of a delta?

Identifier:  imarina:9378367

Handle: https://hdl.handle.net/20.500.11797/imarina9378367

Authors:  Ferréol Salomon, Patricia Terrado Ortuño, Pierre-Alexis Herrault, Kenji Fujiki, Olivier Finance, Ada Lasheras González c , Josep-Maria Macias-Solé, Arthur de Graauw, Kristian Strutt, Simon Keay

Abstract:
Today, anthropic morphologies in river deltas are widespread. The natural morpho-dynamics interact with engineered structures or urbanisation and shape hybrid features not grasped in traditional natural classifications of deltas. However, it is challenging to reconstruct the trajectory of the shifting balance between the natural and the anthropogenic factors over time. This study demonstrates how to systematically integrate human impacts to reconstruct the evolution of deltas at a plurisecular timescale. The approach advocated here is to consider separately the local and global drivers affecting deltaic evolution in using multiscale interdisciplinary chronologies. The high-resolution reconstruction of the evolution of the Francolí Delta in interaction with the city of Tarragona for the last two centuries reveals that the river mouth morpho-dynamics are successively deflected, interacting with an outer harbour and finally fully integrated in modern harbour basins with more significant dredgings at the river mouth. In this last case, the river mouth of the Francolí is no more a delta but a human dominated estuary. Over the past three centuries, the changes affecting the delta of the Francolí are linked to economic globalisation and associated with an increase in ship size.