Climate Change, Submergence and Rice Yield: Evidence from Coastal Barisal, Bangladesh

In this paper, we investigate the effects of submergence due to heavy rainfall and river over-flow on rice production in the coastal Barisal region of Bangladesh. Our study uses plot level data to compare rice yields of cultivars in high and low submergence prone areas and to analyze variation in yield when high-yielding varieties (HYVs) versus local eeds are used. Results suggest that rice yields are, on average, some 10% lower in ‘high submergence areas' relative to ‘low submergence areas'. Both depth of submergence and duration have a negative effect on yield, with local varieties of rice seemingly better adapted to submergence. The widely grown Aman variety of rice faced an average of nine days of submergence in 2010, with 31% plots under 1-3 meters of water for 3-7 days. We forecast that an additional 13,564 hectares or 61% of total cropped Aman area in Barisal is likely to be inundated for 3-7 days in 2050 due to sea level rise and increased storm surge events. Correspondingly, given current levels of technology, we can expect a production loss of 10,856 tons of Aman in the future. The study recommends the introduction of submergence tolerant rice cultivars and low-cost water control technologies as adaptation options against climate change.