Seasonal and regional limits to growth of water-intensive crop farming in Bangladesh

摘要

Irrigation-led expansion of crop farming raised demand for groundwater in Bangladesh. This study aimed to reconcile cropped areas compatible to future water demand using secondary data on cropped area, crop yield, food intake, water footprint, rainfall, river-flow, etc. Yearly and seasonal time series were used in forecasting of areas and yields for all categories of crops. Out of total 76.5 bm~3 water consumption for crop farming in the early 2010s, 34.1 bm~3 was supplied through irrigation of which 79.8% was from groundwater and that would reach at 100.5, 46.6 and 88.2%, respectively in 2029-30. However, pulses, oilseeds, vegetables and potato were identified as feasible crops on the basis of groundwater demand, dietary-balanced self-sufficiency and domestic resource cost ratio. Any reduction of cereal and sugarcane areas over projections and its adjustment with feasible crops would save about one and a half billion m3 of groundwater in dry season. The demand for diversification effort index justified the necessity of initiating special crop diversification projects for the country's Eastern Hills, North Central and North East regions. Moreover, any initiatives for building water reservoirs might facilitate for sustainable groundwater management in the long run.