Assessing urban forest decline and predicting future expansion: a spatial analysis and modeling approach in João Pessoa City, Brazil

Evaluating the decline of urban forests and forecasting urban expansion are pivotal for fostering environmental sustainability and shaping greener, healthier urban landscapes. This study investigates the reduction of urban forests and the patterns of urban development in João Pessoa, Brazil, from 1990 to 2016, and projects future growth scenarios for 2030, 2035, and 2040. Utilizing Landsat imagery, the research assessed urban sprawl through the Normalized Difference Vegetation Index (NDVI) and Normalized Difference Built-up Index (NDBI), alongside land use mapping via Google Earth Engine. Predictive modeling of urban expansion employed the Land Change Modeler software. Findings indicate a marked increase in built-up areas from 36.70 to 44.06% between 2001 and 2018, alongside a reduction in non-built-up regions (primarily vegetation) from 61.63 to 53.95%. The analysis forecasts a trend of urban growth extending concentrically from existing urban centers, with a significant decrease in vegetated areas anticipated by 2040. These insights underscore the critical influence of infrastructure and urban facilities on urban development trajectories, underscoring the need for proactive planning measures to ensure that urbanization progresses in harmony with environmental preservation.