Where the ground is hardest: machine-mapped impervious surface across the NJ Highlands, 2020

Impervious surface share across the New Jersey Highlands region (3,475 km2 of watershed lands supplying drinking water to much of northern New Jersey), aggregated to a hexagonal grid (1 km edge, roughly 2.6 km2 cells). The source layer was machine-mapped from NJGIN four-band aerial imagery with a Raster Vision semantic segmentation pipeline I built and operated for the NJ Highlands Council: 1,651 image tiles per imagery epoch, inference distributed across 10 to 20 AWS Spot instances, predictions vectorized and published by the Council as open data. Region-wide, 8.3 percent of Highlands land was impervious in 2020 (287 km2); the densest cell is 55 percent. Each hex carries land area, impervious area, and percent, so you can restyle or re-threshold it in any GIS.