Contenu du sommaire

The Retreat of the Forest in Northeastern Brazil. The example of the Caatinga of Cariris Velhos. In the sertâo of Northeastern Brazil, the rhythm of land clearing experienced a significant change in the first half of the 1980's. To a large extent, this change was brought about by growing demand for ligneous combustibles on the part of the Northeastern industrial sector. There was a change of attitude, at least temporary one, among the local people as respects the dry forest ; until then considered mainly as transition land for animal raisers, it has since become a direct income producing source. This economic exploitation, however, has never taken the form of a rational management of the forest resources, and it has remained a pioneer activity that has even aggravated the negative evolution of the natural sertanejos environnement.

The Iron Industry in Chile ; Prosperity and Decline. The Chilian iron industry has its origins in a long mining tradition, which goes back more than seventy years and which suffered from economic constraints and, recently, from changes linked to developments in the international iron market and to internal modifications resulting from the different economic programs that have been applied in the country since 1971. Still, iron production remains one of the economic pillars in North Chico it is also one of the main revenue producers as respects foreign commerce and the nation's balance of payments.

Towns and Urban Network in Bolivia. The history of the Bolivian urban system is closely related to the mining exploitation which gave the country its reputation until the latter years. At the beginning of the 17th century, the city of Potosi was known as one of the largest in the world on account of its famous silver mines. It then declined rapidly and was overtaken by Oruro which, in the 18th century, became the largest centre of tin production. In the 19th century, the town of La Paz asserted its preeminence, followed by Cochabamba whose second place was subsequently taken away from it by Santa Cruz, today in full expansion. At present, the agricultural colonization of the Oriente has replaced the traditional mining exploitation in its urbanizing function. With more than a million inhabitants of the six and a half that live in Bolivia, La Paz still remains the largest city of the country. The narrow site on which it was founded, the Chukiyapu River Valley, standing at an altitude of 3,600 meters above sea level, can't cope much longer with a population increase whose annual growth rate is, at the moment, between four to five per cent. Therefore, once the steep valley slopes are occupied, the developement of La Paz must stretch out in two directions : down the Chukiyapu River on the southern side of the city and up-river on the other side, first to the edges of the Altiplano, and then on the Altiplano itself where the city of El Alto, standing at an altitude of 4,000 meters above sea level and with a population of 600 ,000 inhabitants, today constitutes an extension of the original city.

Demographic Growth of Bogota During the Twentieth Century. Since the beginning of twentieth century, Columbia has experienced an «explosion» in its urban growth, but the present urban network is apparently well-balanced among the metropolises, cities of medium size and small towns, in spite of a distinct trend towards further urbanization of the Capital, Bogota. The urban growth of Bogota is due both to a strong natural movement linked to progress in hygiene conditions ; but the latter has been slowed down because of ageing of the population.

The Urban System and New Rural Settlements in Nicaragua. Social, political and economic changes in Nicaragua in the past ten years have led to the institution of a different regional model and a new urban hierarchy. In addition, because of the military conflicts on the borders with Honduras and Costa Rica, an attempt has been made to develop new population settlements, called «asentamientos humanos ».