Water usage trends under intensive groundwater-irrigated agricultural development in a changing climate – Evidence from Bangladesh

Comprehensive information on the past trend of local-level water usage of the cultivated crops is important for agricultural planning and forecasting water needs. This vital information is however deficient for the North-West (NW) region of Bangladesh. We estimated actual crop evapotranspiration (ET), total and crop-usable effective rainfalls (TER and ER, respectively) and irrigation requirement (IR) of 8 major crops and 8 cropping patterns over historical period (1985–2015) by using SWBcropwat model and trends of these water parameters by using MAKESENS tool for the 16 districts of the region. ET of the Rabi crops and cropping patterns revealed significant (p ≤ 0.05) decreasing trends in all districts, the average decrease being 13–31% in different districts. ER decreased significantly for most dry…