A Região Setentrional da Baixada Fluminense

Resumo

The author, Geographer of the National Council of Geography studies the northern part of the Baixada Fluminense, coastal lowland in the State of Rio de Janeiro. The morphological units of the regions are divided as follows. The large alluvial plain, which is in turn divided into clayish alluvial plain constructed by continental waters, and sandy plain, constructed by the sea, the tabuleiros, terraces, characterized by ferruginous concretions, the areas adjacent to crystalline hills, which can be observed at regular levels, and the mountainous massifs composed of crystalline rocks. These units are described and their morphological evolution is studied. The Aw type of climate, Koppen, predominates in the region under study, original vegetation is composed of forests. In a general way, it may be said that to each unit corresponds a dominant or characteristic soil type, regosols in the sandy plains, anuvial in the clayish plain, latosols or regosols on the tabuleiros, orange latosols, red-podzolic latosols and litosols on the crystalline areas. The influence of historic, economic and social facts is noted on the economic geography of the region, with the development of an important sugar-cane growing zone surrounded by areas with a complementary economy, these areas produce firewood and manioc as well as cattle and are in turn surrounded by a zone where small coffee plantations are associated to cattle-raising. The sugar-cane production is the one in which large investments are made and this is an important factor which helps the occupation of the more fertile soils of the Campos region. The anuvial soils. Sugar-cane spreaded over the tabuleiros adjacent to the clayish anuvial plain and originated the organization of drainage systems on periodically flooded areas. Cattle-raising predominates on the lower crystalline zones where orange latosols occur This activity comprises beef as well as work cattle which is used in the sugar-cane area. Within the crystalline area, where intergrade latosolic-podzolic soils occur, the farms present coffee plantations besides the cattle-raising activity. On the tabuleiros of the extreme north of the state of Rio de Janeiro, where intergrade latosolic-regosolic soils occur, there exists an interesting zone with numerous small farms which have manioc and its flower as their basic commercial products. Within the coastal area, besides the cattle-raising activity, the forests still existing on regosols and badly drained alluvial are used for firewood which is consumed by the sugar-cane zone. These various zones of the northern Baixada Fluminense are studied in this article, it is observed that the relations between these zones and the various soil types were formed during the historic evolution of the region.