Inland waters of South America (rivers, lakes, waterfalls)
The topography and climate of South America determined its exceptional richness of surface and underground waters, the huge amount of runoff, the presence of flowing rivers of the world — the Amazon. Occupying 12% of the Earth’s land area South America receives about 2 times more (1643 mm) average rainfall per unit throughout the area. Full river flow is 27% of the total runoff of the Earth, the average runoff depth (58 cm) is also almost 2 times higher than the average value for the entire land. But the volume of flow fluctuates dramatically by mainland — from several mm to hundreds see Very unevenly distributed and the river between the basins of the oceans: the Pacific in 12 times less than the Atlantic basin (the watershed between them is mainly on the ridges of the Andes); in addition, about 10% of the territory Yu. a. refers to areas of internal drainage that crosses the continent from the Gulf of Guayaquil through the Central Andean plateau to the southern pampas. The river is dominated by rain feed, in the extreme South — also snow-glacial.
The higher layer of the medium annual flow 150-400 cm (up to 90% of precipitation) reaches in the South of Chile, due not only abundant rainfall, and steep slopes, low evaporation and ice reserves in the upper reaches of rivers, causing summer flooding, including the “transit” rivers of Patagonia; the share of the underground supply of the rivers of the Southern Andes are not more than 20-25%. As big runoff (some rivers even up to 800 cm) in the West of Colombia, but there is dominated by rainfall and a rainfall of the summer-autumn floods; groundwater runoff increases to 40%. Similar characteristics of flow and the Amazon, decreases in its Central and southern parts up to 40-60 cm in the Regime of large rivers, like the Amazon depends on the rainy season in the upper and middle reaches of its tributaries. The well and more or less evenly wetted the fringes of the Brazilian and Guiana plateaus average annual runoff is also 40-60 cm (sometimes 150 cm) with the share of underground runoff of up to 50%. In the interior of the Brazilian plateau, the flow is reduced (to S.-V. to 5 cm) and becomes extremely uneven: the turbulent summer floods give way to drastic reduction of water flow in winter, up to drying of small streams. A similar flow regime and on the plains, subequatorial and tropical zones with rain rivers (the Llanos of the Orinoco, the plains of Beni-mamoré river, Gran Chaco). Pronounced seasonality in rainfall leads to runoff variability (average runoff decreases from 50-80 to 15-20 cm) and regimes of the rivers: in winter of the respective hemisphere sometimes the flow stops and even large watercourses (Rio Bermejo, Rio Salado, etc.) are broken up into separate pools with salty water, in the summer floods flood vast areas; the regulators of the flow of the rivers Paraguay and Parana are bog-lacustrine lowlands of the river plate basin and the Pantanal lowlands. The lowest levels (3-5 mm) are confined to a deserted tropical West A. J. where the melted snow water from the highlands accumulate in the foothills of the plumes and tectonic depressions, increasing to 50% the proportion of underground power episodic rivers (only the Loa river has a permanent flow into the ocean).
A large amount of rainfall brought from the Atlantic ocean, high plateau, gently sloping down to the vast lowlands and plains, and collects runoff from the adjacent slopes of the Andes, contributed to the formation of wandisco on the East Y. A. large river systems: the Amazon, Orinoco, paraná with Paraguay. Uruguay; in the Andes is the largest system of the Magdalena, in the current longitudinal trough humid Northern Andes. For shipping fit mainly river lowlands. Mountain rivers of the Andes mountains and plateaus, abundant rapids and waterfalls (angel, 1054 m, Kaieteur, 226 km, Iguazu, 72 m, etc.), and flowing watercourses a permanently wet plains have huge hydropower potential (300 million kWh).
Large lakes, mostly of glacial origin (leaf pools), concentrated mainly in the Patagonian Andes (Lago Argentino, Buenos Aires, etc.) and in the South Middle Chile (Llanquihue, etc.). In the Central Andes is the highest mountain of the great lakes Land — Titcaca, there are many residual lakes (Poopo., etc.) and large salt marshes; the latter is also typical of depressions between Paninski siders (Salinas Grandes, etc.). Large lagoon lake located on the North (Maracaibo) and in the Southeast Y. A. (Lagoa DOS Patos, Lagoa Mirim).