ABSTRACT
The mountain chapter in the Agenda 21, accepted in the United Nations Conference on Environment and Development (also known as the Rio Summit or Earth Summit), held in Rio de Janeiro in June 1992, marked the beginning of a mountain water policy at regional to global scales. Mountains account for 20 to 50 percent of total discharge in humid-temperate regions and 50 to 90 percent in arid and semi-arid regions. Increasing impacts of climate change and of human activities on mountain ecosystems – especially on mountain water resources and their signifi cance to the adjacent lowlands – are serious and challenging problems for future mountain research and development. Transboundary river systems, beginning mostly in mountain regions, cover nearly half of the Earth’s land surface and concern about half of the world’s population. Therefore the Alpine and the Carpathian conventions have played a key role in stimulating other mountain regions’ governments to develop similar agreements for a better transboundary and peaceful management, preservation, and development of common natural and cultural resources.
