Comparative analysis of methods applied in vegetation cover delimitation using Landsat 8 images

Abstract

There is a wide availability of methods and techniques for classification of data from remote sensing images. However, one of the biggest challenges is to identify whether the applied method is really effective for the thematic mapping the terrain features. Thus, the aim of this work was to provide a comparative analysis involving data classification methods for mapping forest cover using orbital images from the Landsat 8 satellite. The applied method consisted of pre-processing the images, calculating the NDVI image, performing the infrared image composition and principal component analysis (PCA). The maximum likelihood classification method (MAXVER) was used to delimit the vegetation cover applied to the three types of databases. To validate the classification results, field data, Kappa analysis and pixel-by-pixel analysis were applied. The results pointed out that the NDVI method showed the least general similarity regarding to the reference data used for validation from the MAPBIOMAS project. It was possible to identify similar results in relation to the delimitation of forest cover. The results allowed identifying that the several methodologies available for classification of vegetation are of great value for the thematic mapping of forest resources. In addition, we conclude that the PCA showed the best capacity for delimiting the vegetation cover in the study region, closely followed by infrared composition, and the NDVI was the least accurate.

Association between forest resources and water availability: temporal analysis of the Serra Azul stream sub-basin

“…In the study region, Dutra (2021) discusses, through water balance analyses, that changes in land use have provided a decrease in the maximum storage of the basin's water volume, since the expansion of urban areas together with the agricultural and mining activities in the region have provided greater suppression of vegetation and consequent changes in the sub-basin's hydrological cycle, such as the reduction in the water volume of the reservoir throughout the analyzed time series. According to Dutra (2021) and Dutra et al (2020Dutra et al ( , 2021, the main consequence of these activities is the increase in the output of water, mainly due to grants, in relation to the inflow, arising from natural processes, such as precipitation. In addition, according to Dutra (2021) 2017) reported that the connection between forest areas must be ensured to guarantee local biodiversity.…”

Biomass Model and Water Balance Application for Watershed Drought Analysis

“…The Serra Azul stream sub-basin is especially important for the water supply of Belo Horizonte Metropolitan Region because of the presence of a water supply reservoir managed by Companhia de Saneamento de Minas Gerais (COPASA in Portuguese). This region is located between the parallels 20º 15 'and 20º 00' south latitude and the meridians 44º 15 'and 44º 35' west longitude (Figure 1), encompassed in the municipalities of Mateus Leme, Igarapé, Juatuba and Itaúna (Dutra et al 2021;Dutra, Brianezi & Coelho 2020;Dutra, Elmiro & Garcia 2020).…”