How the numbers are made
Inputs. 16,184 Mapflow building footprints with heights over 5.05 km² of central Belém: Nazaré, Batista Campos, Cremação, Umarizal, Reduto, Jurunas and Campina. Every building is treated as residential. In 3D, each building is extruded to its Mapflow height.
Terrain. A 1-arc-second elevation model (about 30 m cells; 3–20 m across most of the area) is drawn under the 3D view with its relief exaggerated 3×. Buildings stand on the terrain surface at their Mapflow heights.
Population. IBGE Census 2022 counts for the 124 census tracts that overlap the area. A tract cut by the boundary contributes in proportion to the share of its area inside, which gives 62,024 residents.
Census tracts + volume. Each tract's residents are split across the buildings inside it by volume (footprint × height). Downtown blocks with few residents get fewer people per m³ than the low-rise blocks of Cremação and Jurunas.
Volume only. The same 62,024 residents split across all buildings by volume (2.58 per 1,000 m³), ignoring tract counts. Compared with the tract model, it puts about 17% of residents in different places.
Grid. H3 resolution 10 (average edge 75.9 m; cells are ≈1.77 ha at this latitude). A building that crosses cell edges is split by footprint share, so cell totals add up to exactly 62,024.
Download the H3 grid (GeoJSON)
Buildings and heights come from Mapflow, which extracts them from satellite and aerial imagery. Learn more at mapflow.ai