Acknowledgements

The authors wish to express their thanks for the support given by the Chilean Scientific Council (Conicyt) through the project FONDECYT 1110298, 11121287, and Conicyt/Fondap/15130015. Also it is important to express our gratitude to the Chilean Dirección General de Aguas and the Comisión Nacional de Energía Nuclear for the support given to some of the works here described.
