Usage

Prerequisites

1. A subset of the NOAA NextGen Hydrofabric in either GeoJSON or as a GeoPackage.

   Note If using GeoJSON, you will need files for both the divides and nexus layers.

2. A realization configuration file
   1. Compiled shared libraries
   2. Model initialization files, if necessary
3. (If performing channel routing) A routing configuration file with reference to it in your realization configuration
4. (If using MPI and partitioning) A partition configuration file

Running

Once you have the necessary prerequisites, all that's left is to call your ngen executable with the correct CLI arguments.

ngen \
  <divides.geojson or fabric.gpkg> \
  <divides subset ids or "all"> \
  <nexus.geojson or fabric.gpkg> \
  <nexus subset ids or "all"> \
  <realization.json> \
  [partition.json]

Example with GeoJSON Hydrofabric Layers

• Divides path: path/to/divides.geojson
  • Subset: cat-1, cat-3, cat-7
• Nexus path: path/to/nexus.geojson
  • Subset: nex-1, nex-2
• Realization path: path/to/realization_cfg.json

ngen path/to/divides.geojson "cat-1,cat-3,cat-7" path/to/nexus.geojson "nex-1,nex-2" path/to/realization_cfg.json

Example with GeoPackage

• GeoPackage path: path/to/fabric.gpkg
  • Divides Subset: cat-1, cat-3, cat-7
  • Nexus Subset: all
• Realization path: path/to/gpkg_realization.json

ngen path/to/fabric.gpkg "cat-1,cat-3,cat-7" path/to/fabric.gpkg "all" path/to/gpkg_realization.json