evaluateDroughtNema: Evaluates Drought Conditions Based on Raster Time Series.
In henningte/herdersWDA: Functions for Raster Based Weather Time Series Analysis

Description Usage Arguments Details Value Examples

evaluateDroughtNema evaluates based on a set of weather variables as raster based time series (RasterBrick or RasterStack object, if for a given spatial and temporal point drought or near drought conditions are prevalent or not (according to the classification of the NEMA).

evaluateDroughtNema(precipitation, ltmprecipitation, airtemperature,
  ltmairtemperature, ltsdairtemperature, dailymaxairtemperature, dailymeanrh,
  naturalzonesraster, resolution = "monthly", timedate_aggregated,
  timedate_daily, cores = 10, clcall = NULL)

`precipitation`	A `RasterBrick` or `RasterStack` object with (mean) total precipitation values for each time interval within the target time period. See the details section.
`ltmprecipitation`	A `RasterBrick` or `RasterStack` object with long-term mean total precipitation values for all time intervals denoted by `resolution` within a year. See the details section.
`airtemperature`	A `RasterBrick` or `RasterStack` object with mean air temperature values for each time interval within the target time period. See the details section.
`ltmairtemperature`	A `RasterBrick` or `RasterStack` object with long-term mean air temperature values for all time intervals denoted by `resolution` within a year. See the details section.
`ltsdairtemperature`	A `RasterBrick` or `RasterStack` object with standard deviation values of mean air temperature values within the time interval considered as long-term time interval. See the details section.
`dailymaxairtemperature`	A `RasterBrick` or `RasterStack` object with daily maximum air temperature values within the target time period. See the details section.
`dailymeanrh`	A `RasterBrick` or `RasterStack` object with daily mean relative air humidity values within the target time period. See the details section.
`naturalzonesraster`	A `RasterLayer` object containing information on landcover classes for which additional criteria concerning drought conditions are defined. Classes that should not be considered must have the value "0". Mountainous regions must have the value "1". Forest steppe and steppe must have the value "2". The gobi-desert must have the value "3".
`resolution`	A character value indicating the temporal resolution of the `Raster*` time series data for the target time period (`precipitation` and `airtemperature`). One of `"monthly"`, `"ftdi"` (fixed ten-day intervals) or `"mwtdi"` (moving window ten-day intervals).
`timedate_aggregated`	A `POSIXct` vector containing the time information for each band/layer of `precipitation` and `airtemperature`.
`timedate_daily`	A `POSIXct` vector containing the time information for each band/layer of `dailymaxairtemperature` and `dailymeanrh`.
`cores`	The number of cores to be used in parallel computing.
`clcall`	A function passed to `clusterCall`.

The start and end time point of the target time interval are derived from timedate_daily. All time intervals of timedate_aggregated are supposed to fit perfectly within timedate_daily (i.e. there are no more or less days in timedate_daily). All Raster* time series data are supposed to have the same spatial extent an resolution. precipitation and airtemperature are supposed to have the same temporal resolution. dailymaxairtemperature and dailymeanrh are supposed to have the same temporal resolution.

A list with the first element representing daily values if drought (2), near drought (1) or no drought (0) conditions prevail, as a RasterBrick object, and the second element being equal to timedate_daily and indicating the time information relating to the layers of the first element.