| COLOMBIA CLIMATE
Colombia is bordered by Panama and the Caribbean Sea on the north, Venezuela and Brazil on the east, Equador and Peru on the south, and the Pacific Ocean on the west. Colombia's topography is characterized by the Andean Cordillera range, situated in the west-central part of the country, and which stretches from north to south, almost along the whole length of the country. The Andes are composed of three parallel ranges : the Eastern Cordillera, the Central Cordillera, and the Western Cordillera. Between the Cordilleras there are high plateaus and fertile valleys which are crossed by the country's major river systems. Colombia's climate varies with the altitude. The low regions and valleys are arid, with average annual temperatures ranging from 24 degrees C to 27degrees C. Between roughly 455 m and 2,285 m in altitude, the climate is subtropical, and 2,285 m and 3,048 m, the climate is temperate. In the capital, Bogota, the annual average temperature reaches 14 degrees The areas above 3,048 m are the cold climate zone, and temperatures range from minus eighteen degrees C to thirteen degrees. All year long, and for periods of three months, the rainy season alternates with the dry season. There is much rain along the Pacific Coast. At Bogota, annual precipitation reaches 1,015 mm on the average. The summer is the principal rainy season. The eastern lowlands and the Caribbean and Pacific coastal lowlands have tropical and equatorial climates with high temperatures and humidity throught the year and abundant precipation of over 1,000 millimeters. There is nocompletely dry season, although the north and the northwest have a comparatively drier winter. In the mountain regions, climatic conditions are much more complex and varied. These variations depend of altitude, topographic position, and extent of exposure to prevailing winds and the sun. There are often extremes differences over short distances, especially with regard to precipitation. Slopes facing rain-bearing winds are amply supplied with rainfall, while the adjacent sheltered slopes and valleys have a dry climate. But climatic differences, which are reflected in the natural vegetation and which determine types of agricultural activity, are related mainly to the vertical zoning of the Andes, where natural conditions provide the full range of climates, from the torrid equatorial type to the permafrost of areas above 15,000 feet. Colombia is made up of two major physical regions: the
Andes, with its large valleys and basins in the west; and the broad
lowlands, which extend over almost two-thirds of the country in the east.
The population is concentrated in the valleys and basins of the mountain
region, while the lowlands are sparsely inhabited. The physical structure
of the mountain region and the direction of its main ranges and valleys
are a dominant factor in the distribution of the population, with orientation
toward the Caribbean (rather than the Pacific) coast, where most of the
The Andes The mountain region consists of three ranges of the Andes: Cordillera Occidental, Cordillera Central, and Cordillera Oriental, all of which have a general south-north orientation. The Cordillera Oriental has a complex and varied structure. It consists of short, noncountinuous ridges that follow a north-south direction, with some ridges running nearly parallel. This is particularly so in the middle part of the range, from the vecinity of Bogota northward, where it reaches its maximum width of 140 miles. The Cordillera Oriental rises well above the snow line, and extensive areas are snow covered the year around. Another feature of the Cordillera Oriental is a number of high basins, three of which are comparatively large, resembling intermont plateaus. The Capital Bogota stands in one of these basins, the gently sloping surface of which is 8,000-9,000 feet high, which places the basin within a cool climatic zone. The Cordillera Central is the highest and most formidable of the Andean ranges in Colombia, with several peaks rising above the snow line. Pico Cristobal Colon, in the extreme north, is the highest peak at 5,776 meters and among the number of active volcanoes the highest is Tolima, at 5,215 meters; it last erupted in 1829. In the extreme north, in the Sierra Nevada de Santa Marta, the Cordillera Central rise again above the snow line with the strong relief characteristic of the high Andes. This range, which is approximately 40 miles wide, has many small, populated valleys at different altitudes; taken as a whole, however, the range is only sparsely inhabited. The Cordillera Occidental is much lower and narrower. It highest peak is only about 10,000 feet. Even in its high southern part, it has convenient passes. The range decends gently into the Caribbean coastal plain, where it becomes partly sumerged under thick beds of sediment deposited by the rivers draining the Colombian Andes. A deep and mostly narrow valley, drained by the river Cauca, runs between the Occidental and Central ranges. Like the Cordillera Central, the Occidental has only small valleys, in which most of the population lives. The Cauca and some adjoining valleys constitute one of the most densely inhabited parts of the country, with two of Colombia's four largest conurbations, Medellin and Cali. The lowlands The lowlands along the Caribbean coast in the north consist mainly of a low-lying flat plain formed by the extensive deposition and accumulation of sediments carried down by the Cauca, Magdalena, and a few smaller rivers. This alluvial plain is interspersed with hills, descending spurs of the Andes, that extend in a south-north direction. The central part of these lowlands, especially around the mouth of the Magdalena, is one of the most densely inhabited areas of Colombia. The extensive lowlands of the east,
which cover nearly two-thirds of Colombia, belong to two large drainage
basins, that of the Orinoco river in the north and the Amazon river in
the south, and to two natural landscape regions, the Llanos in the north
and the Selvas in the south. The westernmost fringes and some outlying
spurs of the Guiana Highlands and of the Andes extend into the eastern
lowlands. This give the vast undulating plain most of its topographical
variety and its elevated areas, which rise well above the wide floodplains
of the great rivers that
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