Spatial assessment of groundwater use potential for irrigation in Teesta Barrage Project in Bangladesh

In Bangladesh, development of the groundwater resource for irrigation is a vital component of the government’s agricultural strategy to attain food self-sufficiency. Amidst reports of falling groundwater levels in many parts of Bangladesh, the potential of groundwater use has been investigated in the Teesta Barrage Project (TBP) in which large-scale groundwater development for dry-season irrigation has taken place in the recent past. Several techniques and tools have been applied such as the combination of analysis of groundwater hydrographs and mathematical modelling to derive key hydrogeological variables, calculation of net irrigation requirement and the use of geographical information systems. The results show that the economically attractive high-yielding variety (HYV) Boro (dry season) rice cultivation during the groundwater irrigation season may not be sustained in large parts of the project area if the current trends in abstraction are continued. However, due to spatial variation in abstraction, nine thanas (sub-districts)—out of a total of 21 in the project area—may still be able to expand groundwater-irrigated cropland and a groundwater-use potential of 40 mm/year may be created if deep-set shallow tubewells are used by the farmers to abstract groundwater. A structured approach, based on zoning of potential areas, is recommended for groundwater development and use.