Trevors, J. T., & Weiler, P. (2013). Challenges, issues and research in transboundary water systems. Environmental Development, (7), 1-5.
The world’s oceans, rivers, lakes, and groundwater systems span natural boundaries and politicalborders. Large water systems cover most of the planet, but they tend to be managed by nationalgovernments in a fragmented manner that endangers food supply, human livelihoods, and threatensecosystems. Transboundary freshwater basins including river basins, aquifers and lakes are some ofthe most humanly populated areas of the biosphere. These basins are also some of the most highlystressed and environmentally sensitive areas on the planet. There are about 263 watersheds that crossthe boundaries of two or more countries, representing over half of the Earth’s continental surface, 40%of the global human population and include about 145 nations that have territories within theseinternational basins (UNDP, 2012a). Currently, these basins are challenged with a multitude of waterquality and quantity issues coupled with the added stress of continued population growth andeconomic development. By 2025, the United Nations estimates that about 1.8 billion people willinhabit countries or regions facing water scarcity, and as much as two-thirds of the world’s populationcould be facing water stress (UNEP, 2008).