Acknowledgements The authors would like to thank the Spanish Ministry of Science and Innovation (PCIN-2013-074) and the European Union (Marie Curie Career Integration Grant PCIG9-GA-2011-293535 and SANITAS ITN Project agreement 289193). Serni Morera was awarded an FI scholarship from the Catalan Government (2015FI_B2 00071). Lluís Corominas received the Career Integration Grant (PCIG9-GA- 2011-293535) from the EU and the Ramon y Cajal Grant (RYC-2013- 14595) from Spanish Government. LEQUIA has been recognized as a consolidated research group by the Catalan Government with code 2014-SGR-1168. The authors also acknowledge the support from the Economy and Knowledge Department of the Catalan Government through the Consolidated Research Group (2014-SGR-291) e Catalan Institute for Water Research.