Alaskan Tundra Surface Water Mosaic Detected from Maxar Satellite Imagery (2001-2021)

### Access
All files can be accessed and downloaded from the directory via: [http://arcticdata.io/data/10.18739/A26Q1SK18](http://arcticdata.io/data/10.18739/A26Q1SK18).

### Overview
This data product contains surface water bodies (excluding ocean) detected from the near infrared band of Maxar satellite imagery across the Alaskan tundra region, as defined by the Circumpolar Arctic Vegetation Map (https://www.geobotany.uaf.edu/cavm/). Maxar satellite imagery was acquired between the years 2001-2021 at a spatial resolution of <1 meter (m). The dataset is stored in GeoPackages organized into grid cells—tiles and subtiles—following the Polar Geospatial Center Mosaic indexing scheme. Each 100 kilometer (km) × 100 km tile contains a 5 × 5 grid of 20 km × 20 km subtiles.

Each GeoPackage includes: (i) the original raster water mask named "water\_raster\_mask" and (ii) a vector layer named "water_vector" derived from the mask boundaries. The vector layer also reports water-covered area (m²) for each polygon. Filtering removes very small objects (< 500 m²) and masks the ocean boundary (National Snow and Ice Data Center) to reduce spurious features.