The Pampas proper are a natural region in South America. It is the vast, grassy central plain of Argentina. It extends from the coasts of Uruguay River, Rio de La Plata (River) and Atlantic Ocean, in the east, to the Sierras Pampeanas (Pampean Mountain Range) in the west. It includes six Argentinean provinces: Buenos Aires, Santa Fe, Cordoba, La Pampa, Entre Rios, and San Luis. Thus, this fertile plain of South America covers an area of 1,200,000 Km2 (463,322 square miles). In the east the pampas are low-lying (between 30 and 150 m above sea level), with flat sinkholes and ancient valleys. Although the Pampas are characterized by a rich, black top soil, sandy dune-like hills are found in the west, especially in the province of San Luis and western portion of La Pampa province. In the southeast, in the province of Buenos Aires, there are two low ridges: the Sierra de Tandil and Sierra de la Ventana, which rises up to 1,250 m. These ridges are geological outcrops of the Brazilian crystalline basement, which consists mostly of basalt.
Climate
The climate in the Pampas is humid and temperate (mild), becoming more continental to the west. However, in winter, a cold dry wind blows from the southwest, from the Patagonia region. This wind is called 'pampero'. The average January temperature ranges from 19° to 28°C, and the average July temperature varies from 6° to 10°C. However, in the summer, temperature sometimes can rise up to 39° C, for a couple of days, creating a low-pressure zone. This draws cool moist winds from the southeast, creating the conditions for thunderstorms. In the east, the precipitation falls evenly throughout the year, averaging between 800 and 950 mm annually; the west, on the other hand, receives an average, yearly rainfall of 300 and 500 mm, falling in summer. Violent thunderstorms, with abundant rainwater, usually take place in the summer, and drizzle in autumn.
Rivers
The Pampas region’s main rivers are the Paraná, Uruguay, and Rio de La Plata in the east, with its tributaries, the Carcaraña and Salado, which flow from northwest to southeast. In the east, the Pampas are marshy, especially in the province of Entre Rios, and crossed by drainage canals; the west has no surface waters, and groundwater is used. The eastern section of the plain was once covered with forb and grassy vegetation growing on fertile black soils (like the prairies of North America). The west was a dry scrub steppe on gray-brown soils. Now the Pampas are cultivated (wheat and corn) or used for pasture. They are Argentina’s main economic region.
Vegetation, Wildlife, and Economy
A temperate steppe vegetation grows on this plain in the southern part of South America. Therefore, the vegetation consists of grasses and other herbaceous plants. The most typical grasses are meadow grass, feather grass, Aristida, oniongrass, brome, quaking grass, fescue, and koeleria; other common herbaceous plants are campions, sandworts, lupines, vetches, and red verbenas. The family Compositae is represented by ragwort, and there are many plants of the iris, myrtle, and nightshade families. Animals include white-tailed deer, pumas, Pampas cats, armadillos, and vizcachas. The economy is based on cattle livestock raising and agriculture (wheat, corn, soyabean, etc.). The largest cities are Buenos Aires, Rosario, and Cordoba.
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| Above, the map of Argentina shows Pampas region marked off by the black line and the blue line of Uruguay River. |
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| The flat grassy plain of the Pampas |
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| This flat grassy land is excellent for raising livestock and for the dairy industry. |