Altiplano
The Altiplano (on Quechua and Aymara Qullaw ) is a plateau without drainage in southeastern Peru and western Bolivia between the high mountain ranges of the western Andes ( Cordillera Occidental ) and the eastern Andes ( Cordillera Oriental ).
location
The extended plateau located in the central Andes between 13 ° S and 27 ° S is called the Altiplano. In practice, it is the area that encloses the 3 km contour line. The Altiplano then runs for 1800 km along the backbone of the mountains from southern Peru, through western Bolivia to northern Chile and northern Argentina, and varies between 350 and 400 km in width.
The Altiplano lies at an average altitude of 3600 m and extends over an area of around 170,000 km². In the north of the Altiplano is Lake Titicaca , the largest high mountain lake on earth.
Emergence
The Altiplano has developed since this region sank sharply towards the western and eastern Cordillera at the beginning of the Cenozoic era (65 million years ago) , so that kilometer-thick sediment deposits formed.
Since the Miocene (20 million years ago) there has been brisk volcanic activity in the Western Cordillera, through which stratovolcanoes from today up to 6000 m height have formed. Even today, hot steam and sulfur springs on the edge of the Altiplano testify to this young volcanism.
Since the beginning of the Pleistocene two million years ago, an uplift of the intermontane basin has started. The center of the Altiplano and smaller sub-basins in the south were dominated by large lakes ( Lake Ballivián ) for the past 30,000 years . The freshwater lakes from this time had an average depth of 20 to 70 meters, which indicates a significantly higher rainfall than today. The end of the last glacial period and the beginning of the Holocene around 10,000 years ago ushered in a significant climate change - it got warmer, but the amount of precipitation decreased.
Climate and vegetation
The climate of the Altiplano is cold and semi-arid to arid . Average annual temperatures vary between 2 ° C in higher, waterless areas and around 10 ° C on Lake Titicaca. The night temperatures are often below freezing point, especially during the dry season (May to August), while the average maximum daytime temperatures reach up to 15 ° C depending on the location. The annual precipitation varies depending on the topography and latitude. Towards the tropic to the south, they are less than 200 mm, while in the north on the shores of Lake Titicaca and towards the Cordillera Real they can reach over 800 mm. Snowfall is rare and is most likely to occur between April and September.
The entire Altiplano belongs to the vegetation form of the treeless highland steppes . The largest part has characteristics of the Puna , a high mountain steppe with a humid climate. The brittle Ichu grass is omnipresent here and takes on a golden yellow color in the dry season. Some peripheral areas of the northern Altiplano have vegetation that resembles the páramo , a type of landscape with relatively high humidity and low annual temperature fluctuations.
The southwestern part of the Altiplano is desert-like.
Waters
Important bodies of water besides Lake Titicaca in the north are Lake Poopó and the Salar de Coipasa salt lake in the middle Altiplano and the Salar de Uyuni salt lake in the south. Lake Titicaca and Lake Poopó are connected by the Río Desaguadero .
population
The Altiplano has been a central settlement area since it was first settled around 10,000 years ago, where places of worship and irrigation terraces of ancient civilizations were found.
The Bolivian city of La Paz has developed on the eastern edge of the Altiplano and extends from a basin of 3100 m up the steep slopes to the 4000 m high plateau; the megacity of El Alto is directly adjacent on the plateau. Further to the southeast there are the major cities of Oruro and Potosí . The Altiplano is one of the highest human-populated areas on earth. The Altiplano is predominantly inhabited by the Aymara and Quechua people.
economy
Due to the climatic conditions at high altitude, arable farming is only possible to a limited extent; extensive livestock farming is practiced in large areas of the Altiplano. Above all in the edge areas of the Altiplano there are rich deposits of mineral resources that are extracted through tunnel construction , occasionally also in open-cast mining. Many of the ore mines have been so exhausted since the second half of the 20th century that mining no longer makes economic sense. Attempts have been made to mine the lithium deposits in the Salar de Uyuni since the beginning of the 21st century, but so far there has only been one state-sponsored pilot plant. Processing industry can only be found sporadically in the metropolitan areas of the Altiplano and is based on the mining of ores.
Infrastructure
The Altiplano is one of the less developed regions in South America and has only a poorly developed infrastructure . Only important highways are asphalted, such as the national road Ruta 1 between Desaguadero on Lake Titicaca , La Paz, Oruro and Potosí . Many localities have no connection to the telephone network, are insufficiently supplied with drinking water and can only be reached via unpaved country roads.
Web links
- Water resources of the Chilean Altiplano ( Memento of October 24, 2007 in the Internet Archive )
- Altiplano landscape photos of the Altiplano (English)
Individual evidence
- ^ Bryan L. Isacks: Uplift of the central Andean plateau and bending of the Bolivian orocline. Journal of Geophysical Research: Solid Earth 93.B4 (1988): 3211-3231. doi : 10.1029 / JB093iB04p03211 ( pdf )
- ^ Richard W. Allmendinger et al .: The evolution of the Altiplano-Puna plateau of the Central Andes. Annual review of earth and planetary sciences 25.1 (1997): 139-174.
- ↑ Servicio National de Meteorología e Hidrología del Perú (Spanish) accessed on March 14, 2009.