Terrestrial Condition Assessment: Alaska Drought Severity on a 30km Grid

A 3-year weighted drought severity index for Alaska, calculated from U.S. Drought Monitor data. The dataset is a continuous raster with a 30km spatial resolution, produced by the U.S. Department of Agriculture's Forest Service. It was last updated in March 2026.

Use Cases

• Modeling ecological vulnerability based on weighted drought severity scores.
• Analyzing spatial patterns of drought frequency and intensity across Alaska.
• Integrating drought metrics into broader terrestrial condition assessments for land management.

Strengths

• Spatial resolution is explicitly defined as 30km (30000m).
• Methodology for calculating the weighted drought sum (DwSum) is clearly documented.
• Source data is the authoritative U.S. Drought Monitor.

Limitations

• There is a documented lag between the assessment year and the drought data (e.g., 2024 assessment uses 2021-2023 data).
• Column-level documentation is absent; field semantics must be inferred after download.

Provenance

Source

U.S. Department of Agriculture, Forest Service

Collection Method

Weighted sum of U.S. Drought Monitor categories over a 3-year period, summarized at the Subsection scale of the USFS National Hierarchy of Ecological Units.

Time Range

Covers the most recent 3-year period relative to the assessment year (e.g., 2021-2023 for a 2024 assessment).

Freshness

Last updated 2026-03-13 22:50:36.262163

Geography

Alaska, United States