O uso e ocupação do solo no Alto da Bacia Hidrográfica do Rio Gorutuba e impactos na barragem Bico da Pedra e no Projeto de Irrigação do Gorutuba

Abstract

This work consists in the of the use and occupation of land in Gorutuba watershed, located in the north of Minas Gerais.Were different satellite images, as follows: In 1985, Landsat 5 satellite images (TM sensor), and the years 2000 and 2015, using Landsat 8 (OLI Sensor). The results considered three stages of research: usage and occupation of soil in the Gorutuba watershed in 1985, 2000 and 2015. After, are described the main environmental impacts checked in the barrage Bico da Pedra, by virtue of watershed behavior and anthropic occupation around the dam. Lastly, were considered the main productive changes caused by the examined impacts in barrage of Bico da Pedra and the environmental behavior of watershed of alto Gorutuba in the years above mentioned. To do the survey of Gorutuba´s watershed in three different period was necessary different satellite images, in 1985 was used the Landsat 5, in 2000 and 2015 was used the Landsat 8. From the images was possible to create eight classes of different soil usages in Gorutuba´s watershed that allowed comparisons in different time scales. To realize the search that is about impacts from the soil usage and occupation around the watershed, was utilized high resolution images from the satellite Landsat 8, besides camp incursions and bibliographic surveys about the studied subject. The analyzes and reviews performed indicates the presence of edifications around the barrage Bico da Pedra. From the survey of historical data it was possible to detect an increase in the number of buildings caused by many factors, like the default of inspection and the tourism. The consequences caused by this occupation can bring negatives environmental impacts, such as: deforestation of the Permanent Preservation Area, reduction of biodiversity, soil erosion and pollution of water. From the results found in the two steps mentioned above, the third step intends identify the main productive alterations Gorutuba´s irrigation project. To achieve the proposed objective, was used a methodology that consists in bibliographic surveys of authors who deal with credence about the subject, especially about the area of research. Also was used geotechnology tools, like images of high resolution satellite Landsat 8, that allowed to visualize the soil occupation in Valley of Gorutuba. And for validation of prior information it was necessary camp incursions into agricultural areas and public institutions, like the Development Company of São Francisco and Parnaíba valleys – CODEVASF and the District of Irrigation of Gorutuba – DIG. From the production datas, was possible to complete that the behavior of Gorutuba´s watershed, since the second half of 1980 decade to 2015, as well as the impacts from the occupation around the Barrage Bico da Pedra cause significant socioeconomic alterations in the Irrigation Project of Gorutuba, especially in the municipalities of Janaúba and Nova Porteirinha