Hydrometry

hydrometry loads discharge stations and streamflow chronicles. The family is used for basin screening, outlet-response checks, calibration objectives, and post-simulation hydrograph comparison.

Accepted sources

Source	Use when	Source page
custom	Local station and discharge files are authoritative.	custom
hubeau	Hub’Eau hydrometry should discover or download public discharge data.	hubeau

Minimal example

[data.hydrometry]
date_start = "2000-01-01"
date_end = "2020-12-31"

[[data.hydrometry.sources]]
source = "hubeau"
product = "QmnJ"
extent = "watershed"

Visual check

The discharge chronicle should show station identity, date coverage, gaps, and magnitude before it is used for calibration or comparison.

Fig. 156 The first panel is a local hydrometry chronicle. It illustrates the minimum custom-source check: the station has a readable period, magnitude, and event structure before it becomes a calibration or comparison target.

Downstream uses

• observed hydrographs;

• calibration objectives;

• discharge comparison metrics;

• active-network interpretation when combined with hydrography.

Hydrometry Source: custom

Use source = "custom" when project-owned discharge station and chronicle files should be authoritative.

Minimal example

[[data.hydrometry.sources]]
source = "custom"
path = "data/hydrometry"
col_id = "station"
col_x = "lon"
col_y = "lat"
default_crs = "EPSG:4326"
col_datetime = "date"
col_value = "Q"
station_ids = ["J1234010"]

Operational checks

• the location file must identify stations and coordinates;

• chronicle files must expose datetime and value columns;

• source_unit should be set when units are not self-evident;

• rendered hydrographs should be inspected before the data are used in a calibration objective.

Hydrometry Source: hubeau

Use source = "hubeau" when public French discharge observations should be discovered and downloaded through Hub’Eau.

Minimal example

[[data.hydrometry.sources]]
source = "hubeau"
product = "QmnJ"
extent = "watershed"
require_observations = true

Operational checks

• product selects the discharge product; daily discharge commonly uses QmnJ.

• require_observations filters out stations without usable records over the requested period.

• fallback_search_radius_km can be useful when the watershed has no station inside its exact support.

• Cache and lockfile metadata should be preserved for reproducible studies.

Provider replay

Fig. 157 The hydrometry part of the Hub’Eau replay shows why station metadata and chronicle coverage must be checked together. The discharge product should be readable before it becomes an objective or comparison target.