Avaliação da acurácia na classificação de uso e cobertura da terra: um estudo de caso na região intermediária de São Luís com o Mapbiomas

Abstract

Land use and land cover classification is an essential tool for understanding and managing natural and environmental resources. Land use involves activities such as agriculture and urbanization, while land cover refers to physical and biological features, such as forests and water bodies. With advances in remote sensing technologies and geographic information systems (GIS), automatic classification has become feasible in large countries like Brazil. In this context, MapBiomas stands out for mapping land cover and use in Brazil annually from 1985 to the present. This project is notable for its transparency, as it not only discloses accuracy data but also provides the codes and samples used in the process. However, there is an interest in assessing the accuracy of specific study areas, such as the São Luís intermediate region. This region includes several land use classes whose accuracy is not available on the official portal, such as Mangrove, Apicum, Beach, and Dune. This study evaluated the accuracy of these and other classes within the study area. Initially, 712 samples within the SA-23-Z cluster, covering 72% of the study region, were used, later reduced to 655 after preprocessing. The accuracy assessment revealed that the Beach and Dune classes had high accuracy, while Mangrove showed a high commission error, and Apicum was excluded due to the low number of samples. The allocation error was 20%, higher than the national error, reflecting specific classification challenges in coastal environments and sensitive ecosystems. Despite these issues, the Kappa index of 0.62 indicated a strong agreement, confirming the usefulness of MapBiomas data for local analyses, even though adjustments and refinements are necessary. This study contributes to improving public environmental management and developing more specific policies by providing a detailed accuracy analysis of level 2 classes in a strategic region for environmental conservation and development.