← Back to usersum index

Momm 2025 RUSLE2 Isoerodent Data

Vendored Momm et al. (2025) continental-US monthly erosivity data and a matching county GeoParquet companion for planned momm2025 RUSLE R-mode support.

See also: ../../specification.md for the full R-factor contract and mode-boundary guidance.

Overview

This directory vendors a normalized copy of the public dataset released with Momm et al. (2025), "Isoerodent surfaces of the continental US for conservation planning with the RUSLE2 water erosion model," together with a county geometry layer selected to match the dataset's county FIPS coverage.

The goal here is reproducible local access for the RUSLE NoDb mod. The data is not the shipped default runtime R source. It is an implemented optional r_mode that complements the existing cligen_static path:

• cligen_static is the WEPP-aligned approximation path.
• momm2025_county_region is the implemented CONUS RUSLE2 planning-climatology path.
• the locked v1 runtime intent is a scalar run-level R selected from the watershed centroid county, with monthly values preserved in provenance

Files

Source Attribution

• Paper: Momm, H. G., McGehee, R. P., and coauthors, 2025. Isoerodent surfaces of the continental US for conservation planning with the RUSLE2 water erosion model. Catena, 249, 108879. https://doi.org/10.1016/j.catena.2025.108879
• Dataset: USDA ARS Agricultural Data Commons. Data from: Isoerodent surfaces of the continental US for conservation planning with the RUSLE2 water erosion model. https://doi.org/10.15482/USDA.ADC/28821569.v1
• County boundaries source: U.S. Census Bureau, 2010 cartographic boundary counties, 1:500,000. https://www2.census.gov/geo/tiger/GENZ2010/gz_2010_us_050_00_500k.zip

The USDA dataset is published for public access. The vendored Parquet and GeoParquet files in this directory are derivative convenience artifacts created for local runtime use and reproducible repository access.

Metadata

Main Parquet

• Rows: 8,247
• Unique county FIPS: 3,107
• Counties with one row: 2,697
• Counties with multiple REGION rows: 410
• Coverage: conterminous US plus DC; Alaska and Hawaii are not present
• Columns:
  • county identity: fips, state, state_fips, county, county_fips
  • public split label: region
  • monthly erosivity: jan through dec
  • derived convenience total: annual_r

County GeoParquet

• Rows: 3,107
• CRS: EPSG:4269 (NAD83)
• Geometry vintage: 2010 Census county boundaries
• Key columns:
  • identifiers: fips, geoid, statefp, countyfp, name, lsad
  • dataset diagnostics: dataset_row_count, has_split_regions, region_labels, annual_r_min, annual_r_max
  • provenance: source_vintage, source_url

Transformation Notes

The vendored Parquet and GeoParquet are normalized from the public source files with these local adjustments:

• padded county FIPS fields to fixed-width strings
• normalized monthly column names to lowercase jan through dec
• added annual_r as the sum of monthly columns
• restricted county geometry to the exact FIPS set present in the public table
• added county-level diagnostic columns to the GeoParquet for join review and implementation planning

Why 2010 Counties

The public supplement still uses county FIPS values that no longer join cleanly against newer county-boundary vintages. Two observed examples are:

• 46113 - Shannon County, South Dakota
• 51515 - Bedford city, Virginia

Using the 2010 Census county layer preserves those FIPS values and gives an exact county-level join for every row in the vendored main Parquet.

Limitations

• The public supplement does not include polygon geometry for split-county REGION rows.
• A county with multiple REGION rows therefore cannot be spatialized exactly from the public files alone.
• The dataset is a RUSLE2 planning climatology, not a reconstruction of the WEPP storm record for a specific run.
• Coverage is limited to the continental US plus DC.

The lack of public REGION polygons is the main open implementation decision for this dataset. Current runtime behavior therefore keeps centroid-county selection for the county itself, then resolves split-county REGION rows by matching the run's localised annual precipitation against the numeric public REGION interval labels rather than inventing sub-county polygons.

Academic Highlights

The published paper is valuable here because it updates the operational RUSLE2 isoerodent workflow for the continental US in a reproducible way. The high-signal points for this repository are:

• monthly erosivity surfaces are produced for RUSLE2 climate assignment
• the workflow includes small-event handling, spatially varying recurrence intervals, and weighted interpolation
• the authors emphasize smoother spatial and temporal behavior than older hand-built surfaces
• the dataset is better understood as a planning-climatology reference than as a substitute for WEPP run-specific erosivity

Developer Notes

• Prefer reading these assets with the repository .venv, which already has pyarrow and geopandas.
• Do not infer sub-county REGION polygons from the label strings alone; the runtime only uses the numeric interval labels to choose one published row.
• The approved v1 selection contract is watershed centroid, not county-area weighting.
• The approved v1 output contract is scalar R, not a spatially varying erosivity raster.
• If a runtime mode is added, record the exact selected county, REGION labels if used, and any aggregation rule in rusle/manifest.json.