This PR closes the issue #1242.
This PR incorporates lidar-derived elevations for OSM bridges into the FIM. The workflow consists of:

• Extracting lidar-derived elevations for bridges
• Calculating elevation differences between 3DEP DEMs and lidar elevations within bridge areas
• Applying the elevation differences into the final REM

Additions

• data/bridges/make_rasters_using_lidar.py. Generates bridge elevation raster files using lidar data, as described here. This script has to be run on Windows machines. This script must be run twice, each time with a different OSM bridge-lines GPKG file: once for the CONUS and separately for Alaska. The raster files are generated using EPSG:5070 for CONUS bridges and EPSG:3338 for Alaska bridges.

• data/bridges/make_dem_dif_for_bridges.py Compares lidar-elevation raster files with USGS 3DEP DEMs and generates DEM difference raster files at HUC levels, as described here. Non-bridge locations (which make up most of the HUC domain) have zero values, while OSM bridge locations typically show positive values. This script also needs to be run twice: once for the CONUS and a separate time specifically for Alaska.

• data/bridges/conda_fim_bridges_enviro.yml A conda environment file to install conda env needed for running data/bridges/make_rasters_using_lidar.py

• data/bridges/setup_conda_for_make_rasters.txt Provides instructions for running the data/bridges/make_rasters_using_lidar.py script on a Windows machine using a Conda environment.

Changes

• data/bridges/pull_osm_bridges.py The updates include:

  • This script now generates two separate OSM bridge centerline files: one for CONUS and another for Alaska
  • ?

• src/bash_variables.env - Ingests links to two new VRT files for DEM difference rasters (CONUS and Alaska) and the new Alaska OSM bridges GPKG file.

• data/wbd/generate_pre_clip_fim_huc8.py Pre-clips the new Alaska OSM bridges GPKG file.

• src/run_unit_wb.sh Crops the bridge elevation difference VRT file to the buffered HUC boundary and create a copy for branch 0.

• src/run_by_branch.sh Clips HUC-level bridge elevation difference rasters for branches.

• src/heal_bridges_osm.py Now implements two distinct workflows for healing the REM at OSM bridge locations, depending on the availability of lidar data:

  • If lidar data is unavailable: The existing workflow is followed, creating a 10m buffer around the bridge centerline and applying the maximum REN value within this buffer to the entire area.
  • If lidar data is available: The script reads elevation difference rasters and incorporates their values into the REM, effectively healing it at bridge locations. Additionally, it reports the median healed REM values within a 1.5m buffer around bridge centerlines for use in determining bridge risk status.

• src/delineate_hydros_and_produce_HAND.sh Updated to align with the revised input arguments of src/heal_bridges_osm.py

• src/aggregate_by_huc.py Applies 'threshold' HAND/discharge terminology instead of 'max' HAND/discharge terminology for determining bridges risk status.

• tools/bridge_inundation.py. Same as src/aggregate_by_huc.py

• data/usgs/acquire_and_preprocess_3dep_dems.py ??

Removals

Testing

Deployment Plan (For developer use)

How does the changes affect the product?

• Code only?
• If applicable, has a deployment plan be created with the deployment person/team?
• Require new or adjusted data inputs? Does it have start, end and duration code (in UTC)?
• If new or updated data sets, has the FIM code been updated and tested with the new/adjusted data (subset is fine, but must be a subset of the new data)?
• Require new pre-clip set?
• Has new or updated python packages?

Current files / folders to be deployed

• WBD_National_HUC8_EPSG_5070_HAND_domain.gpkg, replaces
  WBD_National_EPSG_5070_WBDHU8_clip_dem_domain.gpkg
• Wbd_national_South_Alaska.gpkg ( new but from other PR from Oct.. see if it is already up to date in all enviros)
• New OSM Files - .../fim-data/inputs/osm/bridges/20250207/
• New pre-clips (coming)

(updates pending)
Diff raster files for each HUC6 (AK huc8)
udpated osm_bridges after lidar processing (each address below, adj for latest editions)

-/inputs/osm/bridges/250207/huc6_dem_diff/alaska/alaska_osm_bridges_modified.gpkg

• /inputs/osm/bridges/250207/huc6_dem_diff/conus/conus_osm_bridges_modified.gpkg
• /inputs/osm/bridges/250207/CanBeDeleted_alaska_lidar_osm_rasters/ (let's keep the "CanBeDeleted" just on EFS, no copy to other enviros)
• /inputs/osm/bridges/250102/CanBeDeleted_conus_lidar_osm_rasters/ (let's keep the "CanBeDeleted" just on EFS, no copy to other enviros)

Issuer Checklist (For developer use)

You may update this checklist before and/or after creating the PR. If you're unsure about any of them, please ask, we're here to help! These items are what we are going to look for before merging your code.

• Informative and human-readable title, using the format: [_pt] PR: <description>
• Links are provided if this PR resolves an issue, or depends on another other PR
• If submitting a PR to the dev branch (the default branch), you have a descriptive Feature Branch name using the format: dev-<description-of-change> (e.g. dev-revise-levee-masking)
• Changes are limited to a single goal (no scope creep)
• The feature branch you're submitting as a PR is up to date (merged) with the latest dev branch
• pre-commit hooks were run locally
• Any change in functionality is tested
• New functions are documented (with a description, list of inputs, and expected output)
• Placeholder code is flagged / future todos are captured in comments
• CHANGELOG updated with template version number, e.g. 4.x.x.x
• Add yourself as an assignee in the PR as well as the FIM Technical Lead

Merge Checklist (For Technical Lead use only)

• Update CHANGELOG with latest version number and merge date
• Update the Citation.cff file to reflect the latest version number in the CHANGELOG
• If applicable, update README with major alterations