conflate_model

URL: /processes/conflate_model/execution

Method: POST

Description:

ripple1d.ops.ras_conflate.conflate_model(source_model_directory, source_network)

Conflate a HEC-RAS model with NWM reaches.

Parameters:

• source_model_directory (str) – The path to the directory containing HEC-RAS project, plan, geometry, and flow files.

• source_network (dict) –

  Information on the network to conflate

  • file_name (str):

    path/to/nwm_network.parquet (required)

  • type (str):

    must be ‘nwm_hydrofabric’ (required)

  • version (str):

    optional version number to log

• task_id (str, optional) – Task ID to use for logging, by default “”

Returns:

Path to the .conflation.json file generated

Return type:

str

Raises:

• KeyError – Raises when source_network dict does not contain a file_name value

• ValueError – Raises when source_network type is not nwm_hydrofabric

Notes

The spatial extents of HEC-RAS river reaches and National Water model (NWM) reaches are not aligned. The conflate_model endpoint resolves these differences by associating HEC-RAS models and model components (e.g. cross-sections) with the NWM reaches they overlap.

1. Generate a concave hull (bounding geometry) around the HEC-RAS source model cross-sections

2. Extract NWM reaches intersecting the hull

3. For each HEC-RAS river reach within the source model,

1. Locate the NWM reaches nearest to the most upstream and most downstream cross-sections

2. Extract all intermediate NWM reaches by walking the network from upstream to downstream

1. For each NWM reach extracted,

1. Locate the HEC-RAS cross-sections that intersect the reach

1. Discard cross-sections that are not drawn right to left looking downstream

2. If no cross-sections intersect the reach, mark the reach as “eclipsed”

1. Mark the HEC-RAS cross-section closest to the upstream end of the reach as the “us_xs ”

2. Identify the HEC-RAS cross-section that is closest to the downstream end of the reach, and then mark the next HEC-RAS cross-section downstream of it as the “ds_xs”

1. If the “ds_xs” would be a HEC-RAS junction, mark the first cross-section downstream of the junction as “ds_xs”

1. If “ds_xs” and “us_xs” are the same, mark the reach as eclipsed

1. Generate a map of the conflated reaches and calculate conflation metrics

Additionally, high and low flows are generated for each reach to bound the SRC generated in later steps. The low flow is 1.2 times the high flow threshold listed for the reach in the NWM network. The high flow is the 100 year flow from the NWM network.