Aplicação da detecção remota e dos sistemas de informação geográfica para a análise da variação temporal do uso e cobertura do solo na bacia hidrográfica do Rio Umbeluzi, 2019-2024

Abstract

Land use and land cover changes in river basins are among the main drivers of global environmental change in many developing countries. In Mozambique and Eswatini, land use and land cover changes cause serious challenges to natural resource management in river basins, especially in the Umbeluzi River basin, which is jointly managed by both countries. These challenges occur in the form of water resource depletion, land use conflicts and are also a key driver of climate change. Remote sensing and Geographic Information Systems (GIS) are effective and frequently used tools for comprehensively understanding the dynamics of land use and land cover changes. The aim of this study was to use remote sensing and GIS techniques to analyse variations in land use and land cover changes in the Umbeluzi River basin for the years 2019 and 2024. For this purpose, satellite images from Sentinel-2 were used, on the Google Earth Engine platform, to compute supervised classification. Supervised classification was performed using machine learning Random Forest (RF) algorithm and the accuracy of the classification was evaluated using confusion matrix. Image processing and mapping were performed based on the ArcGIS Pro 3.2 software. The results showed changes in land use and land cover of the Umbeluzi River basin during the study period. The urban construction decreased by 8%; bare soil or pasture increased by 16.7%; water bodies increased by 77.4%; evergreen vegetation or woodlands decreased by 8.1%; shrublands decreased by 12%; irrigated agricultural area decreased by 30.8%; mangroves increased by 5.6%; small- scale agriculture increased by 4.6%. Classification accuracy consistently achieved values above 0.8 for the indices generated through the confusion matrix. The results of this study have the potential to contribute significantly to the effective management of the Umbeluzi River basin, providing an appropriate analysis of the potential and demand for water resources, integrating the needs of human activities with the ecological sustainability activities of aquatic and riparian habitats.