TheWildland Almanac

Home / The Data

The data

Eighteen biophysical properties, grouped into six themes, mapped annually from the Landsat record at 30 m. The layers are derived with a single, cross-consistent pipeline to produce an internally consistent data cube. Further details are in the documentation PDF on Source Cooperative.

18 properties 6 themes 41 water years 1985–2025 30 m EPSG:5070 COG

Coverage

The Almanac is published in two forms that differ in spatial extent and temporal resolution. California includes all years 1985-2025 and has already been released; CONUS includes 1990, 2000, 2010, 2020 and 2025 and is now released.

Released · v2026.1

Wildland Almanac - California

All 18 properties, water years 1985–2025, statewide at 30 m. The full stack, openly available now. How to access →

Released · v2026.1

Wildland Almanac - CONUS

Conterminous U.S. coverage, applying the same code nationally - all 18 properties for 1990, 2000, 2010, 2020, and 2025, now on Source Cooperative. Disturbance is reported cumulatively between snapshots (rather than annually as in California) and the mask is water-only. Get the CONUS data →

How to read the layer specs

Units, period (temporal aggregation), and notes on method and intended use are listed for each of the 18 properties below. Most layers are single-band int16 with a no-data value of −9999. Water years run October-September.

Vegetation & structure (4) Hydrology (6) Fire hazard (3) Carbon (2) Dieoff risk (1) Disturbance (2)

Vegetation cover & structure 4 layers

Veg_TreeFrac · Veg_ShrubFrac · Veg_HerbFrac · Veg_BareFrac units fractional cover ×10,000  ·  period annual, summer-weighted
Fractional cover of tree, shrub, herbaceous, and bare. The four layers sum to 10,000 at each valid pixel - a Veg_TreeFrac of 9,000 means trees account for 90% of cover. All cover is viewed from above; lower strata hidden beneath the canopy are not counted.
Method: XGBoost on synthetic Landsat imagery (COLD / CCDC), trained on RAP and USFS data.
Canopy height. Canopy height is no longer a standalone layer - it is delivered as the CH band of Fire_LCP (in decimeters, LCP units). The annual 1985–2025 canopy-height record is unchanged; only its packaging moved. Method: XGBoost on synthetic Landsat, trained on the ALS canopy-height data of Allred et al. (2025).

Hydrology 6 layers

WaterFlux_AETmax units mm/yr  ·  period annual sum, water year
Maximum possible annual evapotranspiration given the observed vegetation structure, assuming no drought limitation. Depends on structure, not year-to-year precipitation, so its series is more stable than AETrealized - useful for isolating the hydrologic effect of vegetation change (management, fire, regrowth).
Method: regressions on AmeriFlux observations, monthly Landsat, and PRISM meteorology.
WaterFlux_AETrealized units mm/yr  ·  period annual sum, water year
Best estimate of evapotranspiration that actually occurred, accounting for both vegetation structure and precipitation availability. Always ≤ AETmax; equal in wet years, lower in dry years. Can be compared to independent observations of gauged runoff.
Method: as AETmax, with precipitation-limited monthly water balance.
WaterFlux_Soilmoisture units mm water-equivalent, full rooting zone  ·  period end of water year (Sep)
End-of-water-year soil moisture, from the same monthly water balance that produces AETrealized and Runoff. Potentially useful for diagnosing plant-water stress, the controls on water yield, and live fuel moisture.
WaterFlux_SoilmoistureFrac units fraction of max rooting-zone storage ×10,000 (0–10,000)  ·  period end of water year (Sep)
End-of-water-year soil moisture as a fraction of the maximum rooting-zone storage: 10,000 is a full soil column at the seasonal low point, lower values are progressively drier. Normalizes for differences in storage capacity between pixels, which the absolute WaterFlux_Soilmoisture layer does not.
WaterFlux_Runoff units mm/yr  ·  period annual sum, water year
Best estimate of annual discharge (surface runoff plus subsurface percolation) calculated as precipitation minus AETrealized within the monthly water balance.
WaterFlux_PminusETmax_SPI0 units mm/yr  ·  period annual sum, precip fixed at long-term mean (SPI-48 = 0)
Annual discharge predicted for an average-precipitation year (48-month SPI = 0), computed from AETmax and the long-term-mean precipitation with no net soil-moisture change. Precipitation is held constant, and the layer isolates how vegetation density alone affects water yield.

Fire hazard 3 layers

Fire_LCP units 8 single-band Int32 COGs (FARSITE/FlamMap landscape)  ·  period bands 4–8 annual; bands 1–3 static
The components of a FARSITE/FlamMap landscape for fire-behavior models such as FlamMap, delivered as eight single-band COGs rather than one multi-band file (five vary per year, three are static). The bands, in LCP order: (1) elevation m, (2) slope deg, (3) aspect deg, (4) fuel model (Scott & Burgan FBFM40, categorical), (5) canopy cover %, (6) canopy height dm, (7) canopy base height dm, (8) canopy bulk density kg/m³×100. Bands 1-3 are reprojected directly from LANDFIRE; band 4 is from LightGBM; bands 5-8 from XGBoost/LightGBM predictions drawing on LANDFIRE and on internally processed observations such as the canopy cover described above. Clip and stack the bands to assemble a landscape for an area of interest - see the Use page for the recipe.
Fire_FlamMap_FL units meters ×100  ·  period annual fuels; weather held constant
Predicted flame length from FlamMap using each year's Fire_LCP, with run conditions held fixed (20 mph uphill wind, Scott&Reinhardt crown method, constant, dry fuel moistures). This is a relative indicator of hazard driven by topography and mapped fuel with weather held constant - not an absolute prediction under varying weather conditions.
Fire_FlamMap_ROS units (m/min) ×100  ·  period annual fuels; weather held constant
Predicted rate of spread from the same FlamMap runs as Fire_FlamMap_FL; the same relative-hazard interpretation applies.

Carbon 2 layers

Carbon_AGB units metric tons / hectare (total mass, not C)  ·  period annual, summer-weighted
Aboveground live biomass, mainly tree. Calculated from internally processed observations such as the canopy height and FIA plot observations. Useful for nature-based-solutions accounting and biomass-dynamics tracking.
Carbon_GPP units g C / m² / yr  ·  period annual sum, water year
Annual gross primary production (mass of carbon). Derived from NIRv, flux-tower regressions, and PRISM datasets. The layer to reach for when you need productivity patterns or the climatic and vegetation controls on carbon uptake.

Forest dieoff risk 1 layer

Vulner_TreeDieoff_SPI-2 units unitless index, 0–20,000  ·  period annual
Vulnerability of tree canopy to severe drought - the product of Veg_TreeFrac and the AETmax/precipitation ratio for a 48-month SPI of −2 (a severe drought). Read as a relative index: below ~1,000 is low risk; above ~5,000 is progressively greater. Units are not interpretable in absolute physical terms.

Disturbance severity 2 layers

Observed event-based loss at pixels identified as disturbed by COLD. Pixels with no disturbance in a given year are encoded as 0; −9999 marks pixels outside the study area, masked, or where the pre/post reference is unavailable. Available for water years 1986–2024 - the first and last years of the series cannot be computed.

Disturbance_TreeFrac units Δ fraction ×10,000 (positive = loss)  ·  period event delta
Annual loss of tree fractional cover at disturbed pixels. A value of 3,000 means an absolute loss of 30% tree cover (e.g. 40% → 10%). Disturbance timing for some pixels may be attributed to a slightly different year than the actual occurrence - more often, but not always, the following year.
Disturbance_AGB units Δ tons/ha ×10 (positive = loss)  ·  period event delta
Annual loss of aboveground biomass at disturbed pixels, as the change in Carbon_AGB across pre- and post-disturbance years. Caveats as for Disturbance_TreeFrac.

Before you analyze

Use one release end-to-end. Every annual version reprocesses the full 1985-onward series under one code base, so values for a given year may differ between versions. Do not splice years from different versions in a time-series analysis.
Masking. Layers are masked to the California wildland extent - water, areas outside California, urban and agricultural land, barren/unclassified cover, and a set of non-target ecoregions (the Central Valley and specified deserts). The mask may be imperfect. For landscape-scale statistics (e.g. total biomass over a watershed), treat masked pixels as missing, not zero.
No-data and recent years. No-data is −9999 for all layers except Fire_LCP, where it is 0 (FARSITE convention). Some recent water years are less constrained - WY2023 reflects extreme California snowpack, and WY2025 is subject to refinement in future releases. For year-specific work, compare against nearby years.

License & citation

Released under Creative Commons Attribution 4.0 (CC BY). Free to use, share, and adapt with attribution. Offered as is, with no promise of technical support; please file feedback and reports of errors on the GitHub issue tracker.

University of California disclaimer. The University of California ("UC") makes these materials available pursuant to the following disclaimers: the materials are offered "as is"; user assumes any and all risks, of any kind or amount, of using these materials; user shall use the materials only in accordance with law; user releases, waives, discharges and promises not to sue UC, its directors, officers, employees or agents, from liability from any and all claims, including the negligence of UC, resulting in personal injury (including death), accidents or illnesses, property loss, as well as any and all loss of business and/or profit in connection with user's use of the materials; and user shall indemnify and hold UC harmless from any and all claims, actions, suits, procedures, costs, expenses, damages, and liabilities, including attorney's fees, arising out of user's use of the materials and shall reimburse UC for any such incurred expenses, fees or costs. Use of these materials implies user consent to these terms.
Goulden, M.L. (2026). The Wildland Almanac - California (Version v2026.1). Source Cooperative. DOI: [to be assigned]. Released under CC BY.