Abstract
Copious precipitation in the Meghna Basin has remarkable consequences for floods in the north-eastern region of Bangladesh. In addition, due to climate change more frequent extreme precipitation may also increase the frequency and intensity of flash floods. In this study, a hydrologic model H08 has been applied over the basin at a relatively fine grid resolution (10km). The impacts of climate change are assessed by using the super-high-resolution MRI-AGCM3.2S with A1B scenario through three time-slice experiments; the base-period (1979–2003), the near-future (2015–2039), and the far-future (2075–2099) periods. This study investigates the spatio-temporal changes and the changes in the frequency of precipitation and runoff with different magnitude ranges and finds the implications for water resources management under climate change. Results show that, (a) the projected maximum increment of mean annual precipitation (runoff) is +23% (+34%) and +31% (+39%) during the near-future and the far-future, respectively, (b) the projected increment of median value of monthly discharges at basin outlet is significantly high in wet period (May-July), ranging from 38 to 44% and 25–104% in the near-future and the far-future, respectively. Moreover, the monsoonal peaks are expected to come about 1∼1.5 month earlier, which ultimately lead to higher possibility of earlier flash flood in the future. This anticipated higher increment in peak discharge as well as future shifting of seasonal cycle of river discharge will have significant implications for agriculture and flood disaster management. Findings will also contribute to enhance water resource management in the basin and improve the design of adaptive measures.
Published Version
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