Climate change is supposed to alter not only the mean and variability but also the distribution of rainfall. Changes in rainfall distribution during the monsoon months (June to September) of Bangladesh are evaluated in this study using quantile regression. Monthly rainfall data for the period 1961–2014 recorded at 18 locations distributed over the country were used for this purpose. Distributional changes of monthly rainfall showed downward convergent lines are dominant in peak monsoon months of June, July and August at 28%, 50% and 28% stations, respectively, followed by horizontally divergent lines at 17% of stations during those months. The dominating category of last monsoon month (September) rainfall was found upward divergent lines at 50% stations. The results revealed a decrease in many rainfall quantiles from June to August and increase in September in most of the stations. The increasing trend lines of September rainfall quantiles were found to become more diverse with time, which indicates an increase in rainfall extremes and the possibility of more floods which are already very common in the last month of monsoon in Bangladesh. The decrease in lower quantiles of rainfall in most of the monsoon months may cause an increase in the probability of droughts in the country. The study provided more insight on monsoon rainfall changes and improved understanding of climate change impacts on monsoon rainfall regime which can help in planning climate change adaptations in Bangladesh.

人们认为气候变化不仅会改变平均值和变异性，还会改变降雨的分布。在本研究中，使用分位数回归评估了孟加拉国季风月份（6月至9月）期间的降雨分布变化。为此，使用了在全国18个地点记录的1961-2014年期间的月降雨量数据。月降水量的分布变化表明，在6月，7月和8月的季风高峰月份，向下收敛线占主导地位，分别为28％，50％和28％台站，其次是水平发散线，分别为17％。上季风（9月）降雨的主要类别是在50％的测站上出现了向上发散线。结果表明，从6月到8月，许多台站的降水量减少，而在9月，大多数站的降水量增加。人们发现，9月降雨量分位数的上升趋势线随时间变得更加多样化，这表明极端降雨的增加和洪水泛滥的可能性，这在孟加拉国季风的最后一个月中已经很普遍了。在大多数季风月份，较低数量的降雨减少可能导致该国发生干旱的可能性增加。该研究提供了更多关于季风降雨变化的见解，并加深了对气候变化对季风降雨制度影响的了解，这有助于规划孟加拉国的气候变化适应。人们发现，9月降雨量分位数的趋势线随着时间的推移变得越来越多样化，这表明极端降雨的增加和洪水泛滥的可能性在孟加拉国季风的最后一个月已经很普遍了。在大多数季风月份，较低数量的降雨减少可能导致该国发生干旱的可能性增加。该研究提供了更多关于季风降雨变化的见解，并加深了对气候变化对季风降雨制度影响的了解，这有助于规划孟加拉国的气候变化适应。人们发现，9月降雨量分位数的趋势线随着时间的推移变得越来越多样化，这表明极端降雨的增加和洪水泛滥的可能性在孟加拉国季风的最后一个月已经很普遍了。在大多数季风月份，较低数量的降雨减少可能导致该国发生干旱的可能性增加。该研究提供了更多关于季风降雨变化的见解，并加深了对气候变化对季风降雨制度影响的了解，这有助于规划孟加拉国的气候变化适应。在大多数季风月份，较低数量的降雨减少可能导致该国发生干旱的可能性增加。该研究提供了更多关于季风降雨变化的见解，并加深了对气候变化对季风降雨制度影响的了解，这有助于规划孟加拉国的气候变化适应。在大多数季风月份，较低数量的降雨减少可能导致该国发生干旱的可能性增加。该研究提供了更多关于季风降雨变化的见解，并加深了对气候变化对季风降雨制度影响的了解，这有助于规划孟加拉国的气候变化适应。