Uso de geotecnologias como ferramentas de análise de ambientes susceptíveis à desertificação: o caso do município de Irauçuba-ceará nos anos 2001, 2014 e 2020

Abstract

The problem of desertification in the municipality of Irauçuba, located in the semi-arid region of the State of Ceará in northeastern Brazil, can be studied from the perspective of remote sensing techniques. In this region, there is the presence of human activities such as agriculture and live stock, which have been contributing to the alteration of the landscape of this municipality. In this context, the analysis of images at different times can collaborate in research on desertification and land degradation over the years, thus being a relevant procedure toassess, for example, preventive and mitigating actions that can be applied to the regions where they occur these phenomena. In this sense, procedures will be performed using Remote Sensing techniques to obtain vegetation indices, the normalized difference vegetation indices (NDVI) and the soil adjusted vegetation index (SAVI) as well as obtain ingland use. These results Will be generated from the images of the Landsat 5 satellites, TM sensor and LandSAT 8, OLI/TIRS sensor. Thus, the present work aims to analyze and map the dynamics of vegetation cover in the municipalityof IrauçubaCE and its possible relations with changes duetochanges in land use in the region, in the years 2001, 2014 and 2020, which were chosen according to the quality of the images available and the most relevant periods from the climatic point of view. This was accomplished by obtaining vegetation índices such as the Index for Normalized Difference in Vegetation (NDVI) and the Adjusted Vegetation Index for Soil (SAVI) and the mapping of land use, to associate the response of vegetation changes in land use, as well as identifying possible impacts of agricultural activities on the process of soil degradation, with the proposal of mitigating measures for desertification and land degradation. QGIS 3.10.6 software was used for image processing and calculation of indexes and mapping of land use, as well as for the generation of maps.