“Water Towers”—A Global View of the Hydrological Importance of Mountains

Abstract

Mountains and highlands are often referred to as natural 'water towers' because they provide lowlands with essential freshwater for irrigation and food production, for industrial use, and for the domestic needs of rapidly growing urban populations. Therefore, better knowledge about mountain water resources in different climatic zones is essential for adequate management of these resources. In this chapter, a data-based approach is used that enables the quantification of the hydrological significance of mountains. The study reveals that the world's major water towers are found in arid and semi-arid zones and that pressure on mountain water resources in general will sharpen due to climatic change, population growth, and competing use.