ABSTRACT
The Northeastern part of Thailand has been frequently subjected to drought as results of erratic distribution of
rainfall, dry spells in the rainy season and low water holding capacity of soil. The Standardized Precipitation index
(SPI) is an index based on the probability of recording a given amount of precipitation. Therefore the probability of
rainfall being less or more than a certain amount can be determined. Drought event means a particular rainfall event
gives a low probability on the cumulative probability function. Using this index, the severity and pattern of
droughts are examined. The objective of this study was to analyze Spatial Pattern of Drought in the Northeast of
Thailand using multi-temporal SPI. Daily rainfall data for the period 1976-2004 from 308 rainfall stations
distributed in the Northeast region were collected, analyzed and digitally encoded into GIS database. The Kriging
Method was applied for spatial interpolation of mean annual rainfall to obtain spatial mean annual rainfall for the
whole region. The spatial interpolation of SPI was also done using Kriging Method and the spatial pattern of
drought and its severity were assessed from SPI values at various durations. The result indicated that the pattern of
rainfall increased from southwest to northeast. Moderate and severe droughts were mostly found in the south and
the southwest of the region. The frequency, area extent and severity of drought assessed from SPI could be benefit
for sustainable water resources management and the development of mitigation strategies of drought events in the
region.