This ocurrend as a result of the select and diverse group of participants, the strong support and interest shown by the President of Mexico, the participation of Ministers of State, directors, academic institutions, proyect managers, professors, researchers and many othe types of professionals involved in the multi-dimensional field of water supply and demand. In the knowledge that the seminar left doubts and unfulfilled expectations in the participants concerning the future of efficient water use, a committee was established to draft proposals for follow-up actions and organize activities related to this subject. With this goal in mind, the decision was taken to prepare a book which will serve to provide some of the answers for all those involved in the use and conservation of water resources at the global level. B. Water supply in diminishing in terms of quality and is constant in terms of quantity.
Water distribution is a highly controversial subject, particularly in arid and semiarid zones.
In recent years there has been a growing trend for legislation to transfer the concept of state property to private property in many countries, having gone through the concept of community ownership, which bid not last long in some regions. For this reason the rural and urban worlds are not only a means of living but a way of life. Above all, people's fundamental right to clean water and sanitation at and affordable price should be recognized. In practice, the value water is considered inferior to its real worth and this gives rise to inefficient use. On the other hand, in order to understand the problems of global environmental change, it is essential to establish close collaboration between professionals in the natural sciences and in physics.