{ "stac_version": "1.0.0", "stac_extensions": [ "https://stac-extensions.github.io/raster/v1.1.0/schema.json", "https://stac-extensions.github.io/table/v1.2.0/schema.json" ], "type": "Collection", "id": "whp-2023-continuous-ak", "title": "Wildfire Hazard Potential 2023 \u2014 continuous index, Alaska", "description": "Wildfire Hazard Potential (WHP) version 2023 for Alaska, at the source resolution of 270 m, published as a WGS84 cloud-optimized GeoTIFF and as H3 hex parquet at native resolution 8 with parents 0.\n\n**Hazard, not risk.** Wildfire Hazard Potential describes the likelihood and intensity of wildfire at a location given its fuels, topography and weather. It says nothing about what is there to lose. A remote wilderness ridge can carry Very High hazard with no exposed assets; a subdivision can sit in Moderate hazard and still dominate a risk ranking. Do not read this layer as a map of communities in danger \u2014 for that, use Wildfire Risk to Communities, which combines hazard with exposure and susceptibility.\n\n**This is the cross-domain-comparable product.** The raw WHP index means the same thing in Alaska as in CONUS, whereas the classified product's breaks are computed per domain. Any CONUS-vs-Alaska comparison should be built on this collection, not on `whp-2023-classified-*`.\n\n**Area truth comes from the source grid, not from pixel counts on the COG.** The source is an equal-area Albers grid; the WGS84 COG published alongside is geographic and therefore is not equal-area, so counting COG pixels is not an area measurement. H3 cells at a given resolution are near-equal-area, so cell counts on the hex asset ARE a valid area proxy \u2014 and they reproduce the source's equal-area class shares to within 0.6 percentage points on every class in both domains.\n\n**Effective resolution.** Native H3 resolution is 8, but the source pixel is 270 m in the equal-area projection, which after reprojection is about 169 m \u00d7 337 m at 60\u00b0N. At resolution 8 that is roughly 9\u201313 source pixels per cell, which is what an area-weighted `mean` wants; resolution 9 would multiply the row count for no added information.\n\n**Alaska extent.** Clipped to 180\u00b0W\u2013129\u00b0W, 48.8\u00b0N\u201371.6\u00b0N, which drops the far-western Aleutians (roughly 157\u00b0E\u2013180\u00b0) where the source grid wraps the antimeridian. No National Forest System land lies in the dropped area \u2014 the Alaska units are the Tongass and Chugach, far to the east \u2014 so nothing relevant to Forest Service analysis is lost, but the collection is not a complete Alaska mosaic and should not be described as one.\n\nHawaii is published by the source as a third domain with its own class breaks and is not ingested here; the raw source raster covering it is retained under `https://s3-west.nrp-nautilus.io/public-fire/raw/whp-2023/`.", "license": "public-domain", "keywords": [ "wildfire", "hazard", "fuels", "WHP", "H3", "Alaska", "USDA Forest Service", "Fire Sciences Laboratory" ], "extent": { "spatial": { "bbox": [ [ -173.188, 54.654, -129.984, 71.371 ] ] }, "temporal": { "interval": [ [ "2023-01-01T00:00:00Z", "2023-12-31T23:59:59Z" ] ] } }, "providers": [ { "name": "Gregory K. Dillon, USDA Forest Service Rocky Mountain Research Station, Fire Sciences Laboratory", "roles": [ "producer", "licensor" ], "url": "https://research.fs.usda.gov/firelab/products/dataandtools/wildfire-hazard-potential" }, { "name": "USDA Forest Service Research Data Archive", "roles": [ "licensor", "host" ], "url": "https://www.fs.usda.gov/rds/archive/products/RDS-2015-0047-4" }, { "name": "Boettiger Lab / cirrus", "roles": [ "processor", "host" ], "url": "https://s3-west.nrp-nautilus.io/public-fire/" } ], "links": [ { "rel": "self", "href": "https://s3-west.nrp-nautilus.io/public-fire/whp-2023-continuous-ak/stac-collection.json", "type": "application/json" }, { "rel": "root", "href": "https://s3-west.nrp-nautilus.io/public-data/stac/catalog.json", "type": "application/json" }, { "rel": "parent", "href": "https://s3-west.nrp-nautilus.io/public-fire/stac-collection.json", "type": "application/json" }, { "rel": "license", "href": "https://www.usa.gov/government-works", "type": "text/html", "title": "US Government work \u2014 public domain" }, { "rel": "cite-as", "href": "https://doi.org/10.2737/RDS-2015-0047-4", "title": "Dillon, G.K. 2023. Wildfire Hazard Potential for the United States (270-m), version 2023. 4th Edition. Fort Collins, CO: Forest Service Research Data Archive." }, { "rel": "via", "href": "https://www.fs.usda.gov/rds/archive/products/RDS-2015-0047-4/RDS-2015-0047-4_Data.zip", "type": "application/zip", "title": "Source data package (Research Data Archive)" }, { "rel": "about", "href": "https://research.fs.usda.gov/firelab/products/dataandtools/wildfire-hazard-potential", "type": "text/html", "title": "Wildfire Hazard Potential product page" }, { "rel": "describedby", "href": "https://s3-west.nrp-nautilus.io/public-fire/raw/whp-2023/unpacked/Data/whp2023_GeoTIF/whp2023_cnt_ak.tif.xml", "type": "application/xml", "title": "FGDC metadata as published with the source" } ], "assets": { "whp-2023-continuous-ak-cog": { "href": "https://s3-west.nrp-nautilus.io/public-fire/whp-2023-continuous-ak-cog.tif", "type": "image/tiff; application=geotiff; profile=cloud-optimized", "title": "Wildfire Hazard Potential 2023 \u2014 continuous index, Alaska \u2014 WGS84 COG", "description": "Reprojected from the source equal-area Albers grid to EPSG:4326 with nearest-neighbour resampling \u2014 matching the classified product so the two grids align cell for cell. Geographic, therefore NOT equal-area: use the hex asset for area statistics.", "roles": [ "data" ], "raster:bands": [ { "data_type": "int32", "nodata": 2147483647, "spatial_resolution": 270, "unit": "WHP index (unitless)" } ] }, "whp-2023-continuous-ak-hex": { "href": "https://s3-west.nrp-nautilus.io/public-fire/whp-2023-continuous-ak/hex/h0=*/data_0.parquet", "type": "application/x-parquet", "title": "Wildfire Hazard Potential 2023 \u2014 continuous index, Alaska \u2014 H3 hex (resolution 8)", "description": "One row per populated H3 resolution-8 cell (2,369,388 rows across 3 h0 partitions). Reducer is `mean`, correct for a continuous index. There is no per-feature attribute repeated across cells here, so unlike a vector hex asset `COUNT(*)` is meaningful: it counts cells, and cells are a valid area proxy.", "roles": [ "data" ], "h3:native_resolution": 8, "h3:parent_resolutions": [ 0 ], "table:columns": [ { "name": "whp_index", "type": "double", "description": "Continuous Wildfire Hazard Potential index, the area-weighted `mean` of the source pixels within the cell. Unitless and monotonic \u2014 higher means greater hazard potential \u2014 and, unlike the classified product, comparable between CONUS and Alaska. Averaging is meaningful here because the index is a continuous quantity; do not average the classified codes instead. Source nodata (2147483647) is dropped rather than stored, so this column is never null." }, { "name": "h8", "type": "uint64", "description": "H3 cell identifier at resolution 8. This is the shared join key across the catalog (AGENTS.md) \u2014 use it to join this layer to roadless-areas-2001 and to the other three whp-2023 collections." }, { "name": "h0", "type": "int64", "description": "H3 cell identifier at resolution 0, used as the partition key for hive-partitioned reads." } ] } } }