Utilização das fotografias aéreas nas explorações geográficas

Resumo

            The Central Brazil Foundation (Fundação Brasil Central) is an institution installed 1943 for the purpose to open the interior of Brazil to civilization. Between 8° and 12° of latitude South and 53° and 58° of longitude West this interior is totally unknown. During the years 1944/47 the Expedition of the Foundation marched from the confluence of the Araguaia and Garças rivers up to a site, called Jacaré, on the right bank of the Culuene river, 20 km distant from its confluence with the Ronuro river, where the Xingu takes its name.

            To go on, in direction of Manaus, capital of the State of Amazonas, met with great difficulties. Nothing at all was known about this region and researches among the Indian tribes did not bring any result, which could orient the continuation of the march. With the  collaboration of the Brazilian Air Force, the Foundation therefore took up air-survey3 which, in the start extended only until the Teles Pires, river but culminated in a flight direct from the Jacaré field to Manaus. In this flights great errors of the know maps were found, and in consequence, with the collaboration of the National Geographic Council (Conselho Nacional de Geografia) the present article tries to correct them, so that they can be used for the planning of the Expedition's proceeding, and at the same time as a better preliminary base for cartographic purposes.

            A geological survey of the river Tapajoz was found to be based on a coordinate different from that used in the maps of Brazil. As this coincided with the navigation's results of the flights it was taken as more correct and the course of the Tapajoz river was changed in this place nearly 60 km to the NW. The coordinate is situated the confluence of the divers Teles Pires and Juruena, components of the river Tapajoz.

            In the years 1944/45 the American Air Force had made air-photographs of the whole area. Consulting those the rivers in the line between Jacaré and the confluence Teles Pires-Juruene were reconstructed. This work showed a difference of distance of only one hundredth, considered as exact enough for the mentioned purpose.

            Proceeding thereafter the reconstruction of all the flights made by the AAF, from the established line towards the East until the river Xingu, resulted also a correction of this important watercourse. This result could be controlled by reaching a coordinate on its right bank at the mouth o f the Fresco river. The result was satisfactory.

            During the work the author made also observations about the vegetation and the mean elevations and depressions of the area, which he mentions as a base for further studies.