Modeling on climate induced drought of north-western region, Bangladesh

Abstract

Climate change has occurred naturally over time due to conditional drift, cosmological cycle and changes in volcanic activity and solar energy. Industrial revolutions have changed the balance of natural equilibrium of earth’s climate constituent, making atmosphere warmer than its natural rhythm eventually causing catastrophic consequences on geographically vulnerable countries, which is an established fact by several international organizations including IPCC. Among the vulnerable countries, Bangladesh is facing increasing trend of climatic hazard along with extreme super event. North-western region of Bangladesh is mostly vulnerable to drought. Within the last two decades (1994–2013), annual average maximum temperature has increased by 0.16 °C and the average minimum temperature is forecasted to be increased by 1.3 °C at the end of this century considering the four decadal (1964–2013) trend. Over the last two decades i.e. 1994–2003 and 2004–2013, the annual average rainfall has calculated 151.50 and 138.09 mm, respectively. Rainfall has decreased quite significantly in the last decade. From 1995 humidity level is found to be static in nature. North-western region is an important agricultural hub of Bangladesh. Decrease in rainfall and its seasonal variability have made the region more dependent on ground water for irrigation. Spatial and trend analysis shows groundwater depletion trend is getting steeper in this region. On the other hand, surface water level for every district, except for Pabna, shows negative skewedness. Increasing trend in maximum temperature stimulating high evaporation as well as uncertainty of trans-boundary water movement is found to be strongly influencing the depletion of surface water level. These circumstances are making North-western region more vulnerable towards drought.