Potencialidade e distorções do uso das terras das bacias hidrográficas dos rios São João e Una

Abstract

The area studied is located in the state of Rio de Janeiro, Brazil, including the drainage basin of Una River and part of the drainage basin of Sao João River. There were mapped the soils, the agricultural suitability of lands and class of lands for irrigation, based on preexisting soil surveys, modified and detailed. This paper comprises also the aerial photograph interpretation concerning the soil survey of the coastland region, the land-use mapping and the proposal of a new methodology for the evaluation of land-use distortions accompanied by the corresponding mapping. It is concluded that: 1) In most scanned districts the amount of overused land is not significant; 2) the steady state prevails in the district of Cabo Frio lands, but it is also significant in the districts of Araruama and São Pedro d'Aldeia; 3) there is a prevalence of underused land in the districts of Casimiro de Abreu, Rio Bonito and Araruama. The adoption of management practices according to the orientation of the present study, as well as the reorganization of aims of agricultural exploitation and potential, shall be of use in relieving social and environmental tensions pre-existing in the studied region and in promoting its self-sustainable development.