Acknowledgements
In a study covering such a long-time span, a multitude of researchers and field and laboratory technicians have collaborated. We provide here a list (in alphabetic order) and apologize for any involuntary omission: Laura Aguillaume, Jordi Bartolomé, Cristina Belillas, Susana Bernal, Keith Beven, David Bonilla, Miquel de Cáceres, David Carreras, Sonia Castillo, Lluís Comas, Antoni Escarré, Helena Estevan, Miguel Escudero, Lluís Ferrés, Irene Fraile, Carles Gené, Carlos A. Gracia, Ester Granados, Víctor Granda, Rebeca Izquierdo, Xavier Mayor, Carme Melción, Colin Neal, Noemi Perez, Josep Piñol, Roger Prat, Xavier Querol, Angela Ribas, Anselm Rodrigo, Jordi Serrano, Jaume Terradas and Claret Verdú.
Funding was initially provided by a Hispano-American project which was followed by several projects from the Spanish Government and the European Commission.