Analysis of land use and cover in the hydrographic basin of the Coco River and its implications on Permanent Preservation Areas as a tool in water resources management

Abstract

Studies focused on the diagnosis of the permanent preservation areas (PPAs) in relation to the attendance of the legislation are important for the management of the water resources. In this way, the present work was aimed at the evaluation of the coverage, land use and conflicts of use in the areas of permanent preservation (PPAs) of watercourses in the Coco River basin, located on the right bank of the Araguaia River basin in the state of Tocantins. To do so, the basin's land cover and use was mapped using images from Landsat 8 (OLI - Operational Land Imager) satellite for the year 2015. For the delimitation of the PPAs, the drainage network was manually vectorized in the 1: 5000 scale, using images from the RapidEye satellite. In possession of the hydrography, PPA buffers were created, which obeyed the protection ranges defined by the legislation for each watercourse. Land use conflicts were obtained by overlapping the generated map with the image classification and PPA map. The results of the research indicated that the Coco River basin presents 56.91% of its total area covered by anthropic activities, with a deficit of 32.8% of PPA, with pasture being the dominant use. The Upper Coco River, Ribeirão Piedade and Ribeirão Surubim sub-basins presented the highest percentage of conflict, compared to the other analyzed basins, with 46.03%, 40.1% and 39.35%, respectively. Finally, it was possible to understand, from the study, the distribution of uses throughout the basin, their conflicts and its possible consequences on legally protected areas, can be an effective tool in decision making for investments in conservation actions in the Rio do Coco river basin.