Change of Rainfall Characteristics in Bangladesh and Sri Lanka using more than 100-years Record

South Asian countries are recognized as a vulnerable area of water-related disasters. Due to the recent climate change, the precipitation trends have been changed in some regions. Of course, it is important to examine changes in heavy precipitation because it will cause a flood, but it is also important to describe variation in weak precipitation because weak rainfall is one of the important water resources in agriculture sectors during non-monsoon seasons. Recently Endo et al. (2015) analyzed the precipitation trends in Bangladesh from 1950 to 2008. They showed that as for the total amount of precipitation and the number of the wet day appeared to be increasing over the country. Heavy rain was also increasing in some stations. During the pre-monsoon, seasonal total rainfall, the number of the wet days and weak precipitation were increasing. Heavy rainfall indices showed that inter-annual and decadal variations dominated. The objective is to analyze the long-term rainfall data (1891-2016), and detect the time series variation in Bangladesh and compare with the previous studies.
The results were generally matched with the previous one. By analyzing the short-term trend, it was showed that significant change detected in the research is due to the recent rainfall characteristics change. It implies recent climate change is significant. Trends showed spatial characteristics. Both rainfall amount and intensity are increasing mainly in southern Bangladesh. It will suggest that more active ITCZ could move southward, and this trend will continue. There were different changing trends among seasons. Also, we expand to analyze in Sri Lanka.