Spatial and Temporal Variability of Rainfall over the South-West Coast of Bangladesh

Hossain, Md. Sarwar; Roy, Kushal; Datta, Dilip Kumar (2014). Spatial and Temporal Variability of Rainfall over the South-West Coast of Bangladesh. Climate, 2(2), pp. 28-46. MDPI 10.3390/cli2020028

[img]
Preview
Text
climate-02-00028.pdf - Published Version
Available under License Creative Commons: Attribution (CC-BY).

Download (924kB) | Preview

This study examined the spatial and temporal rainfall variability from the 1940s to 2007 in the south west coastal region of Bangladesh. Time series statistical tests were applied to examine the spatial and temporal trends in three time segments (1948–1970, 1971–1990 and 1991–2007) and four seasons (Pre-monsoon; Monsoon; Post-Monsoon and Winter), during the period 1948–2007. Eight weather stations were divided into two zones: exposed (exposed to sea) and interior (distant to sea). Overall, rainfall increased during the period 1948–2007, while the trends intensified during post-1990s. Post-monsoon and winter rainfall was observed to follow significant positive trends at most weather stations during the time period 1948–2007. The rate of change was found in exposed zone and interior zone are +12.51 and +4.86 mm/year, respectively, over post monsoon and +0.9 and +1.86 mm/year, respectively, over winter. These trends intensified both in the exposed zone (+45.81 mm/year) and the interior zone (+27.09 mm/year) 1990 onwards. Winter rainfall does not exhibit significant change (p > 0.1) over the exterior or interior zone, though individual stations like Jessore, Satkhira and Bhola show significant negative trends after 1990s. Although the trends were observed to weaken in the monsoon and pre-monsoon seasons, they are not significant. Moreover, an 11-year cyclicity was found within these two seasons, whilst no cyclicity was observed in the post-monsoon and winter seasons. Sequential Mann Kendal test reveals that the changes in two zones rainfall trends are started around mid-80s, where step change found only for fours season in Khulna stations and also for winter seasons in all weather stations. These changes may have a detrimental effect on rain-fed agriculture in Bangladesh. The application of palaeo-environmental techniques, threshold determination and rainfall analysis across the whole country could be useful to support adaptation planning of the rain-fed agro-economy in Bangladesh.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Geography

UniBE Contributor:

Sohel, Sarwar

Subjects:

900 History > 910 Geography & travel

ISSN:

2225-1154

Publisher:

MDPI

Language:

English

Submitter:

MD Sarwar Hossain Sohel

Date Deposited:

02 Jul 2019 09:50

Last Modified:

02 Jul 2019 09:50

Publisher DOI:

10.3390/cli2020028

BORIS DOI:

10.7892/boris.123003

URI:

https://boris.unibe.ch/id/eprint/123003

Actions (login required)

Edit item Edit item
Provide Feedback