Subsistemas estuarinos de la bahía de Santander (Cantabria, N de España)

Resum

The bay complex of Santander (Cantabria, NW Spain) is constituted by two mesotidal estuarine subsystems laterally linked that are dynamic, morphological, and sedimentological very different. An elongated (3,115 m) and narrow (100-250 m) sand spit, culminated by vegetated foredunes, confines both Santander and Cubas subsystems. The first one is the broadest, adapted to the Keuper evaporites and clay sediments, as part of the estuarine valley controlled by NE-SW faults; it is very anthropized with an intensive reclamation in the western side and dredging, leading to the dismantling of many inner and outer sand bars for the development of the port of Santander facilities, since the XIX century. In the inner area, there are three coastal streams with low runoff flowing into the old mud flats. The wide sand flat is stabilized on the east side, drained by two shallow submerged tidal channels. The Cubas subsystem is well developed in the eastern area generating a variety of morpho-sedimentary units, among which highlights a flow-tidal delta. It is drained by the river Miera, and broad marshes were reclaimed but they have great potential to be recovered in the medium term when the port of Santander will be extended before 2022. This study is an update of previous works incorporating the main anthropogenic changes due to the expansion of the Santander port.