Abdullah Al-Mamun, Md. Niaz Fa

Abstract

The Standardized Precipitation Index (SPI) was computed in three different cropping seasons namely, Pre-Kharif, Kharif and Rabi based on the monthly precipitation data of thirty-five meteorological stations over Bangladesh during the period 1980–2015. In this study, different features of meteorological drought including frequency of drought, dry and wet periods, percentage of drought area, temporal and spatial variations of drought in Bangladesh were examined. The results revealed that the most significant increasing trend of drought area was found in Rabi season (8.66% per decade) and decreasing trend was found in Kharif season (2.47% per decade). In Kharif season, the trend of drought area was found increasing in northern region with a rate of 2.63% per decade where central region, eastern region and southern and western region were decreasing with a rate of 1.06%, 3.02% and 3.02% per decade, respectively. All drought affected areas were experienced by moderate, severe and extreme droughts in several years during the study period in three seasons. The significant drought events were found in 1992, 2008, 2012 and 2014 in Pre-Kharif, 1981, 1985, 1992, 1994, 2006 and 2012 in Kharif and 1985, 1986, 2005, 2006, 2009, 2010 and 2012 in Rabi season. Some areas of southern and western regions, central regions, eastern regions and most of the northern region were more vulnerable to meteorological drought. Major finding of this study was Pre-Kharif and Rabi season were the most vulnerable to meteorological drought that indicates high seasonal rainfall anomaly in most of the regions of Bangladesh.