Spatial and Temporal Variability of Rainfall over the South-West Coast of Bangladesh
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...
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| Format: | Article |
| Language: | English |
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MDPI AG
2014-04-01
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| Series: | Climate |
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| Online Access: | http://www.mdpi.com/2225-1154/2/2/28 |
| _version_ | 1811326877152837632 |
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| author | Md. Sarwar Hossain Kushal Roy Dilip Kumar Datta |
| author_facet | Md. Sarwar Hossain Kushal Roy Dilip Kumar Datta |
| author_sort | Md. Sarwar Hossain |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-04-13T14:57:06Z |
| format | Article |
| id | doaj.art-569c89c7a6cf43e29d4872dd6c97ed23 |
| institution | Directory Open Access Journal |
| issn | 2225-1154 |
| language | English |
| last_indexed | 2024-04-13T14:57:06Z |
| publishDate | 2014-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Climate |
| spelling | doaj.art-569c89c7a6cf43e29d4872dd6c97ed232022-12-22T02:42:25ZengMDPI AGClimate2225-11542014-04-0122284610.3390/cli2020028cli2020028Spatial and Temporal Variability of Rainfall over the South-West Coast of BangladeshMd. Sarwar Hossain0Kushal Roy1Dilip Kumar Datta2Department of Geography and Environment, University of Southampton, SO17 1BJ, UKEnvironmental Science Discipline, School of Life Science, Khulna University, Khulna 9208, BangladeshEnvironmental Science Discipline, School of Life Science, Khulna University, Khulna 9208, BangladeshThis 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.http://www.mdpi.com/2225-1154/2/2/28rainfall trendsstep changerain-fed agriculture |
| spellingShingle | Md. Sarwar Hossain Kushal Roy Dilip Kumar Datta Spatial and Temporal Variability of Rainfall over the South-West Coast of Bangladesh Climate rainfall trends step change rain-fed agriculture |
| title | Spatial and Temporal Variability of Rainfall over the South-West Coast of Bangladesh |
| title_full | Spatial and Temporal Variability of Rainfall over the South-West Coast of Bangladesh |
| title_fullStr | Spatial and Temporal Variability of Rainfall over the South-West Coast of Bangladesh |
| title_full_unstemmed | Spatial and Temporal Variability of Rainfall over the South-West Coast of Bangladesh |
| title_short | Spatial and Temporal Variability of Rainfall over the South-West Coast of Bangladesh |
| title_sort | spatial and temporal variability of rainfall over the south west coast of bangladesh |
| topic | rainfall trends step change rain-fed agriculture |
| url | http://www.mdpi.com/2225-1154/2/2/28 |
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