Meteorological drought in Bangladesh: assessing, analysing and hazard mapping using SPI, GIS and monthly rainfall data (original) (raw)

This study focused on assessing and analysing meteorological drought characteristics of Bangladesh based on rainfall, standardized precipitation index (SPI) and geographic information system (GIS). SPI and monthly rainfall time series dataset for the period of 1971-2010 were used to define the drought years and severity. GIS techniques, along with inverse distance weighted interpolation, were used to determine the spatial pattern of drought. Drought occurrences with severity were analysed based on 3-month (SPI-3 January and SPI-3 April) and 6-month (SPI-6 April) time scales. Drought occurrence maps were generated in GIS environment by summarizing the percentage of drought occurrence for each category and for each time scale. For drought hazard mapping, a drought hazard index was computed from 34 observation stations using analytical hierarchy process, weighted sum method and drought occurrence with different severities at different time scales. Afterwards, index values were interpolated and classified into four hazard levels viz. low, moderate, high and very high.