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Data Catalog: WaPOR & AgERA5

Source: vignettes/data-catalog.Rmd
data-catalog.Rmd

This catalog provides a comprehensive overview of the geospatial datasets accessible through the Rwapor package, including variables from FAO WaPOR (Version 3) and Copernicus AgERA5.

WaPOR Variables (Version 3)

WaPOR provides data at three levels of detail. Most variables follow a standard scaling of 0.1 to convert integer storage to physical units (e.g., mm).

Level 1: Continental (300 m imagery; 5 km precipitation; 30 km reference ET)

Global coverage. L1-PCP and L1-RET are auxiliary meteorological inputs at their own coarser native resolution (5 km and 30 km respectively, per inst/metadata/wapor_L1.json) — all other Level 1 variables below are ~300 m. The Native Resolution column applies to a variable across all of its listed temporal resolutions — e.g. L1-AETI-D, L1-AETI-M, and L1-AETI-A are all ~300 m, and L1-PCP-E/-D/-M/-A are all ~5 km; only the temporal frequency changes, not the spatial resolution.

Category Variable Name ID Native Resolution Temporal Units Scale Period Portal
Water Precipitation L1-PCP 5 km E, D, M, A mm 0.1 1981+ Links
Water Reference ET L1-RET 30 km E, D mm 0.1 2018+ Links
Water Actual ET & Int. L1-AETI 300 m D, M, A mm 0.1 2018+ Links
Water Evaporation L1-E 300 m D, A mm 0.1 2018+ Links
Water Transpiration L1-T 300 m D, A mm 0.1 2018+ Links
Water Interception L1-I 300 m D, A mm 0.1 2018+ Links
Biomass Net Primary Prod. L1-NPP 300 m D, M gC/m² 0.001 2018+ Links
Biomass Total Biomass Prod. L1-TBP 300 m A kg/ha 1.0 2018+ Links
Moisture Rel. Soil Moisture L1-RSM 300 m D % 0.001 2018+ Links

Level 2: National (100m)

Country-level monitoring for selected countries.

Category Variable Name ID Resolutions Units Scale Period Portal
Water Actual ET & Int. L2-AETI D, M, A mm 0.1 2018+ Links
Water Transpiration L2-T D, A mm 0.1 2018+ Links
Biomass Net Primary Prod. L2-NPP D, M gC/m² 0.001 2018+ Links
Moisture Rel. Soil Moisture L2-RSM D % 0.001 2018+ Links
Productivity Biomass Water Prod. L2-GBWP A kg/m³ 0.001 2018+ Links

Level 3: Sub-national (30m / 10m)

High-resolution data for specific irrigation schemes and river basins.

Category Variable Name ID Resolutions Units Scale Period Portal
Water Actual ET & Int. L3-AETI E, D, M, A mm 0.1 Varies Links
Water Transpiration L3-T E, D, A mm 0.1 Varies Links
Biomass Net Primary Prod. L3-NPP E, D, M gC/m² 0.001 Varies Links
Moisture Rel. Soil Moisture L3-RSM E, D % 0.001 Varies Links
Productivity Biomass Water Prod. L3-GBWP A kg/m³ 0.001 Varies Links

AgERA5 Climate Variables

AgERA5 provides daily agro-meteorological indicators. Data is available globally from 1979 to near real-time (~8 day lag).

Category Variable Name ID Resolutions Units Scale Period Documentation
Water Reference ET AGERA5-ET0 E, D, M, A mm 1.0 1979+ CDS Link
Water Precipitation AGERA5-PF E, D, M, A mm 1.0 1979+ CDS Link
Temperature Min Temperature AGERA5-TMIN E, A* °C (Kelvin converted) 1.0 1979+ CDS Link
Temperature Max Temperature AGERA5-TMAX E, A* °C (Kelvin converted) 1.0 1979+ CDS Link
Energy Solar Radiation AGERA5-SRF E J/m² 1.0 1979+ CDS Link
Atmospheric Wind Speed (2m) AGERA5-WS E m/s 1.0 1979+ CDS Link
Atmospheric Rel. Humidity AGERA5-RHxx E 0-1 1.0 1979+ CDS Link

* Annual Temperature products are provided as average values (AVG-A).

Usage Note: Daily Variables

For daily AgERA5 variables, use the suffix -E (e.g., AGERA5-ET0-E). The package internally translates this to the mapset ID AGERA5-ET0 required by the FAO GISMGR API.

Automatic Data Transformations

To keep analysis workflows simple and scientifically correct, the Rwapor package performs two primary data transformations automatically during data retrieval (wapor_ts() and wapor_map()):

1. Kelvin to Celsius Conversion

  • Target Variables: AGERA5-TMIN-E, AGERA5-TMAX-E
  • Details: AgERA5 temperature variables are archived in Kelvin (K) on the server. Rwapor automatically subtracts 273.15 from the downloaded rasters and any extracted time series.
  • Output Units: The final rasters, metadata, and tables are labeled in degrees Celsius (degC / °C).

2. Daily Rate to Dekadal Totals Conversion

  • Target Variables: Any WaPOR -D (dekadal) variable (such as L1-AETI-D, L2-AETI-D, L3-AETI-D, L1-RET-D, L1-PCP-D, etc.)
  • Details: WaPOR dekadal variables are archived as daily rates (e.g., mm/day). By default, Rwapor automatically scales these rates to 10-day totals (mm/dekad) based on the exact number of calendar days in each individual dekad (10 days for D1 and D2; 8, 9, 10, or 11 days for D3 depending on the month and leap year).
  • Output Units: The final data defaults to mm/dekad or gC/m²/dekad unless the user explicitly requests another unit (e.g., unit_conversion = "day" to keep mm/day).