Analysis of Arrival and Withdrawal Dates of Monsoon Rainfall in Dinajpur, Bangladesh

Abstract

This study was carried out to observe the spatial-temporal pattern of monsoon rainfall, acting as one of the major contributors to Bangladesh's water resources, particularly for agricultural purposes. Daily rainfall and prevailing wind speed for the period of 1986 to 2015 (April to November) of Dinajpur, Bangladesh were collected and analyzed to identify the trend, shifting pattern, and the past and probabilistic future arrival and withdrawal dates for 1 year out of 4, 10, and 25 years. It was revealed that the arrival and withdrawal dates were fluctuating between May to June and August to November, respectively. The mean arrival and withdrawal dates were evident on 3 June, and 27 September, respectively, and most of the dates were in the defined range of June to September. The early arrival dates were between 1 – 53 days except in 1992 (30 days later), and the late withdrawal dates were between 1 – 69 days except in 1987 and 2009 (5 and 10 days earlier). Finally, it was saliently appeared that the probabilistic early (21 May, 9 May, and 30 April) and late (12 June, 29 June, and 8 July) arrival dates are depicting the overall early start of monsoon, while the probabilistic early (13 September, 1 September and 23 August) and late (10 October, 22 October, and 1 November) withdrawal dates are representing the delayed overall withdrawal of monsoon rainfall in the targeted domain. To conclude, the findings of this study would be worthwhile for agricultural and regional planning purposes and, furthermore, for the management of floods and water resources in the North-western region of Bangladesh.

J Bangladesh Agril Univ 19(1): 143–151, 2021

https://doi.org/10.5455/JBAU.15020