In order to detect and monitor drought timely at regional scale, we
propose the TRMM Precipitation Condition Index (PCI), the Soil Moisture
Condition Index (SMCI) and the Temperature Condition Index
(TCI) based on microwave remote sensed TRMM precipitation,
AMSR-E soil moisture and land surface temperature retrievals from
2003 to 2010 (Table 3). The remotely sensed variables were linearly
scaled from 0 to 1 for each pixel based on absolute minimum and
maximum values for each variable over time, in order to discriminate
the weather-related component from the ecosystem component as
done for VCI using NDVI (Kogan, 1995a,b). After normalization, the
scaled value changed from 0 to 1, corresponding to the precipitation
changes from extremely low to optimal.