Cristina Rodrigues Nascimento

GIS APPLIED TO THE STUDY OF TEMPORAL RECOVERY OF BURNED AREAS IN THE MUNICIPALITY OF PAI PEDRO LOCATED IN REGION NORTH OF THE STATE OF MINAS GERAIS

The northern region of Minas Gerais is considered a transition area between the biomes Caatinga and Savanna, with predominance of the Savanna and its variations. It is common to the occurrence of fires, which can be caused naturally or by anthropogenic actions, resulting in changes in the landscape. In this sense, the study aims to evaluate from time series of LANDSAT-5/TM and MODIS/TERRA images the process of natural recovery of vegetation after the identification of operational pixels corresponding to the burned areas. The results of the research are based on the response of the municipality test of Pai Pedro/MG. We can observe that was detected a hotspots pixel on the day 08/04/2008 through images MOD14A1, which validation was performed from the survey of burned areas conducted by INPE National Institute of Space Research. From the identification of operational pixel of burned was evaluated the dynamics of recovery of the area through the vegetation index NDVI (Normalized Difference Vegetation Index), generated by images MODIS/TERRA, product MOD13Q. The scars of burned analyzed, approximately 52% were detected. Despite this limitation, much of the area impacted was identified. The errors of omission were considered satisfactory, with a view to the technical limitations of spatial resolution of the sensors used.

ANALYSIS OF THE PROCESS OF ENVIRONMENTAL DEGRADATION OF AREAS OF SWAMP IN THE REGION NORTH OF MINAS GERAIS FROM TEMPORAL SERIES OF IMAGES

Environmental studies to characterize the process of environmental degradation of different ecosystems are extremely complex. In recent years, satellite images have become a great ally in these types of study, since they have the advantage of allowing the joint analysis of different variables, especially when associated with the temporal series. In this perspective, the study aimed to analyze the process of environmental degradation in areas of meadows, at the southern end of the basin of the Urucuia river, situated in the North of the state of Minas Gerais, from LANDSAT5/TM images. Characterized by a transition region between the biomes savanna and caatinga, areas of meadows suffer strong anthropogenic pressures that are promoting major disturbances and disfiguration of the entire ecosystem. For the analysis were studied images of months more dry (July and August) for the years 1984, 1990, 2000 and 2010. The areas of meadows have been identified and mapped and then there was an automatic segmentation and analysis of the NDVI (Normalized Difference Vegetation Index) to study the dynamics of this environment. The results showed that during the period analyzed, these areas fell by around 9.61 times, mainly due to silting. The NDVI showed behavior similar to those observed in areas of paths, i.e. there was a change on the surface of the water for values corresponding to areas of exposed soil in the advanced stage of deterioration. The greatest period of degradation was observed between the decades of 1980’s and 1990’s with reduction in these areas around 88.29 %.