Caracterização multitemporal das planícies de inundação dos rios Grande e Aiuruoca através da aplicação de técnicas de sensoriamento remoto e SIG

Abstract

Floodplains are transitional environments adjacent to rivers where seasonal inundations frequently occur. They are important for maintaining fish biodiversity due to fundamental influences on the life cycle of a number of species. Within these environments, temporary and permanent marginal lagoons are formed depending on the inundation frequency and on their connectivity to rivers, which provide adequate conditions for the recruitment of species of fish. This study was motivated by a lack of information about flood plains and marginal lagoons along the rivers Grande and Aiuruoca, in Minas Gerais, Brazil, and by the necessity of understanding temporal inundation patterns. Remote sensing image processing was used to quantify the inundated area during the dry and rainy seasons of 2000, 2001, 2006, 2007, 2008 e 2009. These images were also used within a geographical object based image analysis approach to delineate temporary and permanent marginal lagoons. Multitemporal land cover maps were produced in order to quantify changes in vegetation classes, water, and bare soil. Results showed that the size of floodplains and the connectivity during dry and rainy seasons between marginal lagoons and rivers varied for different parts of the rivers Grande and Aiuruoca. These variation patterns were correlated to the water flow control exerted by hydroelectric reservoirs in the region. The application of remote sensing techniques for temporal characterization of floodplains enabled inferences about the dynamics of these systems on different hydrologic periods. Regional scale spatial and temporal analyses allied to biological aspects allow the identification of ecological patterns and provide the basis for planning management and conservation strategies focused on biodiversity maintenance.