Análise da dinâmica de variação das áreas de lagos do Alto Vale do Rio Doce/MG

Abstract

The system of natural lakes in the upper Doce river valley is recognized worldwide due to its landscaping and environmental features. The uniqueness of structural factors associated with its genesis and permanence, its insertion in an area bearing a rich and vast biodiversity and the various anthropical uses of these environments, reinforce the demand to develop further knowledge about the elements that act in its preservation and degradation. Remote sensing techniques, digital image processing and statistical analysis were used aiming to analyze the influence of usage and land cover factors, climatic, morphometric and morphologic on the variation of areas of a set of lakes in the upper Doce river valley throughout a period of 25 years (1985-2010). The outcomes showed no relationship between transformations on land-use and land-cover and the decrease of the layer of water, and for that reason it is not possible to point out activities that pose risks to the maintenance of the investigated aquatic environments. Regarding the influence of climate variables, the performed linear regression models proved to be more expressive concerning the relationships between changes in the areas of the lakes and the accumulated precipitation throughout the year and the accumulated evaporation within fifteen days. The results coming out from the statistical analysis of the morphometry of the drainage basins and the morphology of the lakes indicated that there was not any relationship between the hydrological behavior of the system of natural lakes of the Doce river, evidenced neither by the variation of the areas of its layer of water and the form of the basins nor by the form of the lakes.