Bangladewsh is a riverine  country. According to Bangladesh Water development board (BWDB)  about 230 rivers currently flow in Bangladesh (during summer and winter), although the number stated are ambiguous in some sources. 310 rivers flow in the summer although they republished another study in 6 volumes where stated 405 rivers. The number differs widely due to lack of research on the counts and the fact that these rivers changes flow in time and season.