spi: Calculate Standardized Precipitation Index (SPI)

Description Usage Arguments Value Author(s) References See Also Examples

Description

Calculate SPI and the drought specifications with the length, the drought type and the intensity

Usage

1
spi(prec_data, time_step = 12, distribution = "gamma")

Arguments

prec_data

[zoo] rainfall monthly data in zoo class with date in %Y-%m-%d

time_step

[numeric] by default = 12, time step to sum monthly data (1, 3, 6, 9, 12, 24 and 48)

distribution

[character] distribution of data (log_Logistic, gamma, grev, genlog, normal)

Value

list that contains

spi [zoo] zoo with the spi values with date in %Y-%m-%d

drought_type [zoo] zoo with the type of the period for each month

drought_number [data.frame] dataframe with the number of different period by type

Author(s)

Florine Garcia (florine.garcia@gmail.com)

Pierre L'Hermite (pierrelhermite@yahoo.fr)

References

McKee, T.B., Doesken, N.J., & Kleist, J. (1993) The relationship of drought frequency and duration of time scales. Eighth Conference on Applied Climatology, American Meteorological Society http://www.droughtmanagement.info/literature/AMS_Relationship_Drought_Frequency_Duration_Time_Scales_1993.pdf

See Also

plot_trend: plot the index

Examples

1
How to use function

flogrc/piflow documentation built on May 24, 2019, 7:34 a.m.