Advance Drought Response Index (ADRI)
Is an extended version of IDSI which allows better understanding on drought incidence, duration over the 18years
ADRI is useful tool in drought mitigation studies and in decision-making process.
Formula :
Where, ADRI
ijk, VCI
ijk, TCI
ijk, PCI
ijk and SCI
ijk are IDSI, VCI, TCI, PCI and SCI value for pixel i in composite j of year k.
The ADRI value ranges between 0 to 100; L is the normalization factor to keep the output value in expected range and c is a constant to avoid null in denominator.
The values close to 0 reveals extreme drought situation as vegetation is under stress, precipitation is very low and temperature is very high. Likewise, the values closer to 100 reveals normal situation as vegetation growth is good, precipitation is high and temperature is favourable.