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Compute P95 of AETI Within Crop Class

Source: R/analysis_indicators.R
wapor_calc_p95_aeti.Rd

Extracts the 95th percentile of seasonal AETI for each crop class. In remote-sensing water accounting, the 95th percentile of AETI across homogeneous agro-ecological zones or crop classes serves as an empirical estimate of target (non-water-limited) crop evapotranspiration (ETx), filtering out localized extreme outliers.

Usage

wapor_calc_p95_aeti(aeti_seasonal, crop_mask, min_pixels = 30L)

Arguments

aeti_seasonal

SpatRaster. Seasonal AETI raster.

crop_mask

SpatRaster. Crop mask with integer class values.

min_pixels

Integer. Minimum pixel count to compute P95. Classes with fewer pixels return NA. Default 30.

Value

A data.frame with columns: class_value, p95_aeti, n_pixels, valid.

References

Bastiaanssen, W. G., & Bos, M. G. (1999). Irrigation performance indicators based on satellite remote sensing. Irrigation and Drainage Systems, 13(1), 3-36.

de Bie, C. A., Khan, M. R., Smaling, E. M., Hirosawa, K., & Knox, J. W. (2011). Analysis of the variation in water productivity for irrigated wheat in Egypt. Agricultural Water Management, 102(1), 58-69.