MONITORING DROUGHT VULNERABILITY AT DIFFERENT TIME SCALES: A CASE STUDY FROM RAJSHAHI DISTRICT, BANGLADESH

Drought is a slow onset natural disaster which creates a threat to social and agro-ecological balance. The failure of rain and the occurrence of drought during any particular growing season may lead to severe food shortage and increase vulnerability. The purpose of this study is to estimate the Drought Index (DI) in multiple time scales for Rajshahi district of Bangladesh.The 52 years daily rainfall data during the period 1964-2015 used for analysis. There were some missing data over that range. We separated this time interval in 5, 7 and 10 days series format then we estimate missing value by using imputtation method. Finally, we used R code to analyze Markov Chain Model by considering threshold value 3mm. At first, we find out the Drought Index from the first transition probability matrix and then estimate with higher transition probability matrix. When the higher transition probability matrix became stable, then we estimate the DI. The empirical study showed that for 5, 7 and 10 days Drought Index (DI) followed extreme to moderate, mild to occasional, and extreme to occasionally drought respectively. But in first transition probability matrix it showed chronic drought and due to climate change after different stages chronic drought turned into severe, moderate, mild and occasional drought. In overall interpretation, we found mild for 5 days and occasional drought for 7 and 10 days respectively. By extracting information about drought characteristics that include its spatial extent, severity, and frequency are important for policy maker to take necessary steps in advance to mitigate the effect of drought for producing crops which will reduce the food insecurity and vulnerability for developing sustainable development.