ABSTRACT
Mountains are the water towers of the world-the source of many major rivers and a key component in their hydrological systems. Often storing huge amounts of fresh water in snow and glaciers, their importance is twofold. First, many ecosystems in the mountains or plains depend on the hydrological processes of mountainous regions. Secondly, many populations around the world depend directly on these water resources either for direct consumption, agriculture or industry. Moreover, in many mountainous regions-for instance the European Alps-the tourist trade is also highly dependent on these resources.
