Geotechnologies as support for analysis of natural vegetation in the hydrographic basin of Hawk River (1988 a 2015)

Abstract

The occupation history of the Hawk River sub-basin underwent significant socioeconomic transformations in the last 30 years. Thus, concerns for preservation or recovery of vegetation cover positively influence the maintenance of the sub-basin's hydrological cycle. The present research had as objective to analyze the modification of the natural vegetal between the years of 1988 to 2015 in the hydrographic sub-basin of the river Gavião (semi-arid Brazilian).The techniques of remote sensing and Digital Image Processing (PDI) were used for the acquisition and processing of orbital products (landsat 5 TM and landsat 8 OLI satellites). The Geographic Information System - GIS for storage and analysis of the georeferenced alphanumeric database. The results indicate a reduction of the vegetal cover of 751,69 km ², between the years of 1988 to 2015. In addition, deforestation patches in areas of springs, in the upper part of the drainage network and in the main canal deregulation. Thus, the present research draws attention to the effects of changing natural vegetation to other land uses (exposed soil, planting, among others), the concentration of deforestation in areas of environmental fragility.