DROUGHT RISK EVALUATION USING REMOTE SENSING AND GIS : A CASE STUDY IN LOP BURI PROVINCE

Drought disasters in Thailand have been occurring with increasing frequency in recent years. A drought is one weather hazard that is often underestimated for two reasons. (i) Droughts have a slow rate of onset and, (ii) They have less visual impact on us. However, the long term outcome of a drought can be widespread and very devastating. This drought risk area evaluation study involved the intregration of Geographic Information Systems and Remote Sensing technology. JERS-1 OPS dry season data was acquired for 2 different years and was processed to detect vegetation condition change in response to drought. Physical and meteorological factors were analysed and drought risk areas were identified based on the criteria of Ministry of Science, Technology and Environment (MOSTE) of Thailand. NDVI change between a normal year (1995) and drought year (1997) was analyzed for each drought risk area. It was found that the value of the NDVI is lower in high drought risk areas, which justifies the modified criteria of MOSTE.