Long term droughts, uses data from current and preceding months. Focuses on duration and intensity of large-scale, long-term, drought-inducing atmospheric circulation.
Crop Moisture Index (CMI)
Short-term droughts, weekly scale, useful for farmers to monitor water availability during the growing season.
Palmer Hydrological Drought Index (PHDI)
Measures hydrological impacts of drought (e.g., reservoir levels, groundwater levels, etc.) which take longer to develop and longer to recover from.
