Share streamflow statistics table and add climate model tables to hydrology docs

[brucecrevensten]

Summary

Documentation-only changes to the /conus_hydrology and /arctic_hydrology docs pages:

• Shared streamflow statistics table. The two separately maintained "Available Streamflow Statistics" tables are replaced by a single Jinja fragment (templates/documentation/streamflow_stats_table.html) included by both pages. The table incorporates the full statistic definitions from the hydroviz preprocessing stat_vars_dict: complete descriptions plus new Category and Difference method columns (the latter tells users whether ?source=gcm_diff values are ratios or absolute differences, previously only findable in the source data release).
• Statistics tables moved to the top of both pages, directly after the introduction, ahead of the endpoint/output documentation.
• New climate model tables, one per page, included above the streamflow statistics table:
  • CONUS (conus_models_table.html): the 13 CMIP5 GCMs with modeling center and available RCP scenarios, from the hydroviz gcm_metadata_dict. ACCESS1-0 and BNU-ESM only have RCP 4.5/8.5.
  • Arctic (arctic_models_table.html): the six downscaled runs (CESM2-LE members 2/4/7/9 under SSP3-7.0; PGWh/PGWm derived from SSP2-4.5), from the ak_hydro_segments rasdaman coverage model-axis metadata.

Notes

• ma99 is kept in the stats table (served by the API but absent from stat_vars_dict), using its description from the CSV metadata in csv_functions.py.
• The historical baselines (Maurer for CONUS, the ERA5-forced Blaskey hindcast for Arctic) are described in prose rather than listed as climate models.
• Fixed a few source-text glitches in passing: a duplicated sentence in the dh4 description, spr_mag referring to MH20, and two typos ("Adminstration", "Gephysical").
• Both templates are prettier-formatted.

Manual testing

1. Run the API locally:

   micromamba activate api-env
   export FLASK_APP=application.py
   export FLASK_DEBUG=True
   flask run
   

2. Visit http://localhost:5000/conus_hydrology and check:
   • A "Climate models" table (13 rows) appears right after the intro, followed by the "Available Streamflow Statistics" table (53 rows, with Category and Difference method columns).
   • The rest of the endpoint and output documentation renders normally below the tables.
3. Visit http://localhost:5000/arctic_hydrology and check:
   • A "Climate models" table (6 rows) appears after the intro, followed by the same streamflow statistics table and then the "Available Water Temperature Statistics" table.
   • The streamflow statistics table content is identical to the CONUS page (it is the same fragment).
4. Spot-check a couple of statistic definitions (e.g. dh2, ma99, spr_mag) against the JSON metadata returned by /conus_hydrology/stats/50563 and /arctic_hydrology/stats/81000004.

🤖 Generated with Claude Code

[cstephen]

I added a commit to replace - with a comma in the stat table unit descriptions. Since these descriptions often describe the math involved in calculating each statistic, the - used as a separator can easily be mistaken for a subtraction operation. These were lifted from the CSV metadata descriptions where we need to be careful about using commas, but there's no such problem for the HTML documentation.

For example, this:

(number of days/year - temporal)

Was changed to this:

(number of days/year, temporal)

I also spot checked the new information about models, scenarios, etc. that were added to the documentation vs. the source of this new information (as described in the PR description) to make sure it was correct. I found no errors. This new information looks good and is valuable for the people who want to know it, without cluttering the hydroviz webapp itself.