The city of Valencia is the third city of Spain in terms of population with 1 Million habitants. It is located over the largest alluvial flood plain of the mediterranean basin and corresponds to Jucar and Turia rivers. The area is mainly settled over young unconsolidated fluvial sediments provided by the activity of the rivers and even man-made desiccated areas. The Valencia Plain is filled mostly by Plioquaternary deposits of various origins. Almost all the deposits infilling the plain are of continental origin, although mixed and even marine deposits also exist. Hydrogeologically, the Plioquaternary deposits of the Valencia Plain comprise an important unconfined, detritic aquifer with inter-granular porosity. The aquifer consists of intercalated layers and lenticular beds of conglomerates, sands and gravels, embedded in a silt–clay matrix, making up a single aquifer-unit. The abundance of clay materials makes it an area susceptible to present vertical ground motions for consolidation due to variations in the water table, underground works or overloading of these sediments. Changes on the land-use, ground water exploitation, and the construction of major infrastructures such as the port and the subway network, could have caused an impact on the stability of structures and infrastructures. The port and the subway are two important city infrastructures, vital to the development of the city, whose construction and maintenance are susceptible to produce geotechnical problems. The Port of Valencia is the 5th in Europe in container traffic and one of the world's top 50. The subway network is the third metro built in Spain and is 146.7 km long.
Flat alluvial flood plain and even man-made desiccated areas
Subsidence due to underground construction, ground water abstraction and compressible ground