Installation¶

nwm-gdrom requires Python 3.11 or newer. The runtime dependencies are numpy >= 2 and pandas >= 2; no geospatial libraries are needed for the catalog build and consumption paths.

With pip¶

pip install git+https://github.com/NGWPC/nwm-gdrom.git

There is no PyPI publication; releases are GitHub-only. To pin to a specific tagged release, append @<tag> to the URL.

To install with the optional crosswalk dependencies (only needed once the GRanD-to-NHF crosswalk module ships):

pip install "nwm-gdrom[crosswalk] @ git+https://github.com/NGWPC/nwm-gdrom.git"

With pixi¶

If you maintain the repository as a pixi project, the canonical environments are pre-configured. Clone the repo and run:

git clone https://github.com/NGWPC/nwm-gdrom.git
cd nwm-gdrom

pixi install -e dev          # development env: numpy, pandas, jupyter, matplotlib
pixi install -e release      # minimal env for building the catalog
pixi install -e crosswalk    # adds geopandas, shapely, pyogrio

To run the test suite:

pixi run -e test314 test          # fast tests on the small fixture set
pixi run -e test314 test-all      # full corpus + network tests

Verifying the install¶

nwm-gdrom --help

Should print the CLI usage. If you prefer the Python API:

import nwm_gdrom

print(nwm_gdrom.__version__)

Getting the prebuilt catalog¶

If you only need the binary catalog (the most common case for T-Route integrators), download the latest release artifact directly:

curl -L -o nwm_gdrom_catalog.npz \
  https://github.com/NGWPC/nwm-gdrom/releases/latest/download/nwm_gdrom_catalog.npz

Or pin a specific version:

curl -L -o nwm_gdrom_catalog.npz \
  https://github.com/NGWPC/nwm-gdrom/releases/download/v0.1.0/nwm_gdrom_catalog.npz

You still need nwm-gdrom installed (or the numpy package directly) to load the catalog.

System requirements¶

The catalog build itself is modest:

Resource	Requirement
Disk	~750 MB free for the GDROM v2 download, ~25 MB for the source layout, ~2 MB for the output catalog.
Memory	Peak ~250 MB during build. The catalog resident size is ~23 MB.
Network	One-time ~740 MB download from HydroShare. Skippable if you already have the source archive locally (see CLI reference).
Time	About 15 seconds for the parse, threshold-computation, and pack steps once the source layout is on disk. The HydroShare download dominates wall time.