Rainfall, Floods, and Rice Production in the Ganges-Brahmaputra-Meghna River Basin

The regional characteristics of the relationship between summer monsoon rainfall variability and rice production within the Ganges-Brahmaputra-Meghna River Basin, and those between flood-affected area variability and rice production in Bangladesh are examined for the period from 1961 to 2000 and 1947 to 2010, respectively. In the relatively dry upper Ganges River Basin, local rainfall and rice production were positively correlated. On the other hand, in the lower river basin the positive correlation was not clear and flood influences were dominant. In Bangladesh, a clear relationship has been observed between severe floods and rice production. The production of the dry season rice (Boro) gradually increased after the mid-1960s, in particular after years of severe flooding. After the severe flood of 1998, the production of Boro exceeded that in the rainy season for the first time, and the difference in production between these two varieties has increased since then. As such, rice production in Bangladesh has increased almost continuously in the late 20th century, even with recent frequent severe flood damage during rainy seasons, implying farmers’ adaptation to the recent climate changes.