South America possesses distinctive and diverse river basins that are integral to the continent's natural, cultural, and socioeconomic identities. The geomorphologic and hydrological features of South American river systems are linked to the continent's unique tectonic and geographic settings. High rainfall rates across large interior basins make the Amazon, Orinoco, and Paraná Rivers three of the six highest discharge rivers in the world. Relatively small coastal rivers drain the Guyanas, much of the Atlantic Coast of Brazil, and the entire Pacific margin of the Andes. To the extreme south of the continent, temperate rivers drain the Argentine pampas and Patagonia Steppe. The diverse geographic and climatic settings of South American River Basins produce correspondingly diverse assemblages of riverine habitats and species. Rivers are integral to the welfare and development potential of South America's population, providing services ranging from water supply to important inland fisheries and hydroelectricity. Human pressures on the continent's river systems have lead to widespread contamination, disruption of natural flow regimes, land-cover conversion, and overexploitation of riverine resources. Improved river resource management and sustainable development are inextricably linked in South America.
