This chapter of the first world water development report provides a good overview of the state of the world’s freshwater resources, the water cycle, and current challenges for water management.
UNESCO & WMO (2003): Part II: A Look at the World's Freshwater Resources. In: UNESCO & WMO (2003): WORLD WATER ASSESSMENT PROGRAMME WWAP. The United Nations World Water Development Report 1. Water for People – Water for Life. Paris and Oxford: 67-96. URL [Accessed: 17.04.2012]