Abstract
Understanding the historical and future spatio-temporal changes in climate extremes and their potential risk to rice production is crucial for achieving food security in Bangladesh. This paper presents results from a study on trend analysis for 13 climate metrics that significantly influence rice production. The analysis was conducted using the non-parametric Mann-Kendall test and the Theil-Sen slope estimator methods. The study included data from all available weather stations in Bangladesh and the assessment was done for both the wet (May to October) and dry (November to April) seasons, which cover the growing seasons of the country’s three types of rice: Aus, Aman and Boro. Results show significant decreasing trends for wet season rainfall (>12 mm/season/year in some stations) in the central and north regions. In addition, dry season rainfall is decreasing significantly in many areas, whilst dry season dry spells are increasing throughout Bangladesh. Decrease in rainfall in some of these areas are of concern because of its impacts on rainfed Aus rice and in the sowing/planting of rainfed Aman rice and irrigated dry season Boro rice. The maximum temperatures in the wet season are increasing throughout the country at 0.5°C every ten years, significantly at most of the climate stations. The analysis shows that the number of days with temperature >36°C has significantly increased in 18 stations over the last three decades, which implies a serious risk to Aman rice yield. The current maximum temperatures (both in the wet and dry seasons) are higher than the optimum temperature ranges for rice production, and this will have likely adverse effects on yield in the face of climate change with increasing temperatures. The results herein have practical implications for planning appropriate adaptation policies to ensure food security in the country.
Highlights
IntroductionTemperature, solar radiation, wind speed and humidity have key impacts on agriculture [1–4]
Understanding the historical and future spatio-temporal changes in climate extremes and their potential risk to rice production is crucial for achieving food security in Bangladesh
The increasing trends in the annual total rainfall observed by Rahman et al [21, their Fig 7] in the northwest areas that are in contrast to the results of the other investigators might be due to data limitation in their study since some of the currently available climate stations in that region were installed during 1980s or later
Summary
Temperature, solar radiation, wind speed and humidity have key impacts on agriculture [1–4]. Bangladesh, a predominantly agricultural country, has a monsoonal climate with an intense wet season associated with almost regular flooding [12, 13], and a dry season in which crop production relies on groundwater feed irrigation. Regardless of technological advancements like improved crop varieties and irrigation methods that have made the country almost food secure [18], climatic factors still add uncertainty in agricultural productivity [18, 19]. Inter-annual and intra-seasonal features of the monsoon predominantly control crop production both during the wet May to October and dry November to April seasons [20, 21].Climate variability has been identified as a major cause of changes in crop yield in the country, while increasing temperature and changing rainfall patterns have a deleterious impact on crop production [22]. The declining rainfall reduces infiltration to groundwater [25] and runoff supply to wetlands and seasonally flooded areas [24], which reduce recharge to the underlying aquifers, resulting in a decline in groundwater tables
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
