Dinâmica do fluxo de CO2 associada ao uso e cobertura da terra no município de Morro do Chapéu-BA

Abstract

The increase in the emission of gases that intensify the "greenhouse effect" phenomenon, which are called Greenhouse Gases (GHGs), is carbon dioxide (CO2), one of the main responsible for the increase in global warming. According to the UN, about 4.2 billion tons of CO2 were released into the atmosphere in 2018, the increased release of GHGs is due to the use of fossil fuels, deforestation, burning, and improper land use in agriculture. In Brazil, the largest GHG emissions are linked to land use change and the conversion of natural vegetation to agricultural use, accounting for more than 70% of emissions. In view of this, the scientific community is searching for methods and techniques capable of diagnosing and monitoring the transformations and climate changes in order to contain the advance of environmental imbalance. Thus, in this work, two scientific articles were developed. The first article aimed to evaluate the scientific production regarding methods and techniques applied to the identification of atmospheric carbon dynamics in different uses and coverage. In this article bibliographic data networks were built, as well as graphs and tables. The results achieved were: identification of the evolution in the number of publications, being the decade of 2010 the most expressive; the main trends of publications are focused on understanding the carbon in the soil and how the different types of land use and land cover influence/interact with it, relying on remote sensing techniques; the largest number of publications were developed in regions with a large presence of vegetation, humid to sub-humid, not being identified any work developed in the Brazilian semiarid region. The bibliometric analysis made it possible to recognize patterns in the publications, and also showed that semi-arid or arid areas are still poorly studied in relation to carbon dynamics, as well as the use of techniques that make it possible to work with a robust amount of data, such as Google Earth Engine. The second article discussed the dynamics of atmospheric carbon in different types of land use and land cover in the municipality of Morro do Chapéu - BA. For this, the spatial dynamics of the types of land use and land cover in the municipality were observed through the landscape metrics considering the transitions between classes, as well as the dynamics of CO2flux using the spectral indices of vegetation NDVI, PRI and CO2Flux. Pearson correlation was then performed between these variables in order to understand the relationship between them. As results we generated maps of land use and land cover transition, CO2flux and correlation. It was observed that: Morro do Chapéu has not undergone major transformations in its landscape structure; it was noted that the areas where no process of landscape alteration occurred or exhibited the process of vegetation regeneration were the ones that showed the highest capacity to absorb CO2; the areas with low or no presence of vegetation considered as deforestation, exhibited the lowest values of CO2Flux. The development of new studies should be encouraged, seeking to understand the dynamics of carbon in a more complex way, including other variables such as rainfall, especially in arid or semiarid environments.