Analysis of fluvial dynamics of Cachoeira River (Antonina-PR), between the years 1954 and 2005

Abstract

The area covered by this study is part of the Cachoeira River basin, located in the city of Antonina (PR). This, according to studies already done, denotes greater contribution to the process of silting of Antonina Bay. The research objective was to analyze the dynamics of fluvial Cachoeira river, from morphological and morphometric data, considering the years 1954, 1980, 1996 and 2005. It was used materials such as topographic mapping, aerial photographs of the years 1954, 1980 and 1996 and SPOT 5 satellite imagery of 2005. It was used the database program CAD (Contaminants, Siltation and dredging in the estuary of Paranaguá / PR). It was performed the preparation of mosaics from aerial photographs and satellite images of the four years worked. The Cachoeira river was divided into two parts so that the information obtained could be compared. Three fluvial features (abandoned meander, spit bar and river island) were chosen to be analyzed in two segments. Later, they were defined 10 morphological and morphometric variables for obtaining values of quantitative, linear and area. The result of the morphological and morphometric analysis of the segments of the Cachoeira river  showed that the plain segment had more significant changes over the years studied than the segment saw. It was found that the period from 1996 up to 2005 has suffered the most changes, considering the two segments of Cachoeira river. The morphometric characteristics, the dynamics of land cover and land use and the presence of Hydroelectric Parigot de Souza are examples of factors that explain the changes in the two segments.