earthflux

Reference

Indices

Every index earthflux computes or plans to compute, with the inputs it needs, the published method it follows and how it has been checked. The evidence column summarizes VALIDATION.md. To propose an index, open an issue on GitLab.

Drought

Standardized, Palmer and evaporative-demand indices for meteorological, agricultural and hydrological drought, with the potential evapotranspiration methods they depend on.

IndexInputsMethodEvidenceStatus
Standardized Precipitation IndexSPIGamma or Pearson IIIPrecipitationMcKee et al. 1993Compared with NOAA NCEI climate-division SPIAvailable
Standardized Precipitation Evapotranspiration IndexSPEIGamma, Pearson III or log-logisticPrecipitation, PETVicente-Serrano et al. 2010Matches R SPEI and SPEIbase v2.11Available
Self-calibrated Palmer Drought Severity IndexscPDSINew in 3.0Precipitation, PET, available water capacityWells et al. 2004Cross-validated with a Wells-lineage implementationAvailable
Palmer Drought Severity Index familyPDSI, PHDI, PMDI, Z-IndexPrecipitation, PET, available water capacityPalmer 1965; Heddinghaus & Sabol 1991Validated against NOAA NCEI nClimDivAvailable
Evaporative Demand Drought IndexEDDIReference evapotranspirationHobbins et al. 2016Matches NOAA PSL EDDIAvailable
Potential evapotranspiration, ThornthwaitePETMean temperature, latitudeThornthwaite 1948Reproduces a published worked exampleAvailable
Potential evapotranspiration, HargreavesPETMin and max temperature, latitudeHargreaves & Samani 1985Reproduces a published worked exampleAvailable
Reference evapotranspiration, Penman–MonteithEToTemperature, humidity, radiation, windAllen et al. 1998 (FAO-56)Reproduces FAO-56 worked examplesAvailable
Percentage of normal precipitationPNPPrecipitationStandard definitionRegression testsAvailable
Precipitation Concentration IndexPCIDaily precipitationOliver 1980Regression testsAvailable

Fire

Fire weather and fuel dryness indices that combine temperature, humidity, wind and antecedent precipitation.

IndexInputsMethodEvidenceStatus
Keetch–Byram Drought IndexKBDIDaily max temperature, daily precipitation, mean annual precipitationKeetch & Byram 1968Reproduces the original worked exampleAvailable
Canadian Forest Fire Weather Index SystemFFMC, DMC, DC, ISI, BUI, FWI, DSRNoon temperature, relative humidity, wind, 24-hour precipitationVan Wagner & Pickett 1985Matches the NRCan reference implementationAvailable
Fosberg Fire Weather IndexFFWITemperature, relative humidity, windFosberg 1978Unit testsAvailable
Hot-Dry-Windy IndexHDWTemperature, humidity and wind on pressure levelsSrock et al. 2018Reproduces the published Cedar Fire caseAvailable
Haines IndexHainesTemperature and dew point at two pressure levelsHaines 1988Unit testsAvailable

Flood

Daily accumulated-wetness indices that indicate flood potential. They describe how wet conditions are, upstream of terrain, soils and routing, rather than predicting flooding itself.

IndexInputsMethodEvidenceStatus
Effective precipitationPEDaily precipitationByun & Wilhite 1999Regression tests; no external reference yetAvailable
Effective Drought IndexEDIDaily precipitationByun & Wilhite 1999Regression tests; no external reference yetAvailable
Flood IndexI_FDaily precipitationDeo et al. 2015Regression tests; no external reference yetAvailable
Antecedent Precipitation IndexAPIDaily precipitationKohler & Linsley 1951Regression tests; no external reference yetAvailable

Energy

Climate-driven demand and renewable-resource indicators for energy planners, with the standardized indices that read them as energy droughts. These are new to earthflux.

IndexInputsMethodEvidenceStatus
Heating, cooling and energy degree daysHDD, CDD, EDDDaily mean temperature, heating and cooling base temperaturesNOAA CPC single-base conventionReproduces NOAA CPC's published cooling example; heating and energy degree days are specification-levelAvailable
Hub-height wind speedWind profileWind speed, reference and hub heights, shear methodPower-law or log-law wind profileMatches xclim and windpowerlib on synthetic inputsAvailable
Wind capacity factorWind CFHub-height wind speed, power curve, air densityTobin et al. 2018Cubic curve checked against exact rational arithmetic; no external curve adoptedAvailable
PV capacity factor, temperature-deratedPV CFSurface solar radiation as a mean flux (W m⁻²), 2 m temperature, 10 m windJerez et al. 2015Matches pvlib for the power and temperature term; the thermal model is specification-levelAvailable
Standardized Renewable Energy Production IndexSREPIRenewable production proxy or capacity factor, timescales, calibration yearsAllen & Otero 2023Matches R SEI 0.2.0 on a wind capacity-factor series; beta has no external referenceAvailable
Standardized demand indexDemand indexEnergy demand proxy, timescales, calibration yearsAllen & Otero 2023Matches R SEI 0.2.0 on synthetic demand series; beta has no external referenceAvailable
Standardized Residual Load IndexSRLIResidual-load proxy (signed), timescales, calibration yearsAllen & Otero 2023Matches R SEI 0.2.0 on signed residual series; the subtraction is specification-levelAvailable