Predicting design water requirement of winter paddy under climate change condition using frequency analysis in Bangladesh

The effects of climate change on the agricultural sector are tremendous. Thus, it is essential to determine its impacts on agricultural water resources and to minimize adverse effects on crop production. The present study aims to simulate climate data based on SRES A1B scenario from the outputs of three General Circulation Models (GCMs) namely, FGOAL, HADCM3 and IPCM4 and examine the design water requirement (DWR) of winter paddy using frequency analysis under climate change condition in Bangladesh. The average change rates of DWR in four climatic zones were compared to baseline and the results were −12.16% (2020s), −0.28% (2055s), and 1.25% (2090s) for the FGOAL, −4.44% (2020s), 0.57% (2055s) and 1.25% (2090s) for the HADCM3, and −1.12% (2020s), 2.22% (2055s) and 6.69% (2090s) for the IPCM4. The change rates of gross paddy water demand (GPWD) for three GCMs ranged from −3.01% to 11.16%. In both cases of the DWR and GPWD, the change rates were above 3%, indicating a warning signal to the future winter paddy water management. The outcomes of this study can be used as basic data for the development of agricultural water resource management, which will help to minimize the drought-risk and to implement future agricultural water resource policies in Bangladesh.