Potential crop water requirements of dry season Boro rice under climate change in North-East hydrological region of Bangladesh

Abstract

In the present study, two districts of North-East region of Bangladesh; a flood prone area with high temperature and maximum precipitation, respectively were selected along-with two widely cultivated Boro rice varieties in Bangladesh. Reference evapotranspiration (ET_O) during the study period from 1994 to 2010 was estimated with the daily meteorological data utilizing the FAO Penman-Monteith method. A MAKESENS trend model was adopted for the assessment of both Mann-Kendall test and Sen's rate of change over the study period. During the study period, the potential crop water requirement of Bangladesh Rice Research Institute dhan 28 and BRRI dhan 29 in Moulvibazar has been declined by −3.953 mm year⁻¹ and −5.182 mm year⁻¹, respectively; whereas it has been raised by 2.483 mm year⁻¹ and 2.387 mm year⁻¹, respectively in Sylhet. The climatic parameters affecting the observed and projected trends in Potential water requirement differed both significantly and insignificantly over the months of the year. For both varieties, maximum water demand was observed in mid-season stage; whereas in the development stage, the water demand was found to be minimum. These results, by enhancing our understanding of the special effects of climate changeability on ET_C, will aid ecological planning of water resources employment in the region.