ETP#

etp loads potential evapotranspiration forcing. It feeds the solver’s diffuse evapotranspiration (EVT) process and gives climatic context alongside recharge, precipitation, and temperature forcing.

Accepted sources#

Source

Use when

Source page

custom

A local potential evapotranspiration file (station chronicles or a gridded NetCDF/GeoTIFF) is authoritative.

custom

sim2

SIM2 gridded potential evapotranspiration should be retrieved over the project period.

sim2

Minimal example#

[data.etp]
date_start = "2000-01-01"
date_end = "2002-12-31"

[[data.etp.sources]]
source = "sim2"
extent = "watershed"

All field definitions, types, and defaults live in the generated reference: [data] DataManagersConfig.

Loaded shape#

EtpManager (hydromodpy.data.variables.etp.manager, in the hydromodpy.data layer) returns one of two record shapes depending on the source:

  • custom pointed at a directory of station files returns a list of PointRecord: one entry per station, each carrying a datetime/value time series, a start and end date, and the resolved unit.

  • custom pointed at a single .nc or .tif file, and every sim2 source, returns a list of FieldRecord: a gridded dataset over a bounding box and CRS, with the source period as date_start/date_end.

Both shapes are converted to the internal unit mm/day before reaching downstream code, whatever unit the source file declares or the SIM2 API returns.

Downstream uses#

  • the solver EVT package, built from flow.sinks_sources.etp ([flow] FlowConfig); both the MODFLOW 6 and the MODFLOW-NWT backends assemble it;

  • climatic summaries and reporting alongside Recharge, Precipitation, and Temperature;

  • water-budget checks once ETP has been activated in the flow configuration.

ETP Source: custom#

Use source = "custom" for local potential evapotranspiration forcing.

[[data.etp.sources]]
source = "custom"
path = "data/etp/etp_daily.nc"
source_unit = "mm/day"

The path field accepts either a directory of station location and chronicle files, or a single .nc/.tif file; which one decides the loaded shape described above.

Operational checks:

  • set source_unit when file metadata do not carry explicit units;

  • check period coverage, non-negative values, and stress-period aggregation before ETP reaches the EVT package;

  • mask_path can filter stations or clip a gridded source to a project mask;

  • station_ids restricts loading to an explicit station list when the source directory holds more stations than needed.

ETP Source: sim2#

Use source = "sim2" to retrieve SIM2 potential evapotranspiration fields.

[[data.etp.sources]]
source = "sim2"
extent = "watershed"

extent selects the bounding box used for the request: the delineated watershed, or the broader study area.

Operational checks:

  • use the climatic summary for pre-solver checks, then inspect water-budget terms after ETP has been activated in the flow configuration;

  • set force_refresh to bypass the cache when the SIM2 payload needs a fresh download.