Impact of temperature changes on groundwater levels and irrigation costs in a groundwater-dependent agricultural region in Northwest Bangladesh

Abstract

Changes in hydrological processes due to rising temperatures and related effects on the socio-economy and people’s livelihood are major concerns in Bangladesh. A study has been performed to assess the effects of increasing temperature on the groundwater levels and consequent changes in irrigation costs for groundwater-dependent irrigated agriculture in Northwest Bangladesh. A support vector machine (SVM) was used to model the temporal variations in groundwater level from rainfall, evapotranspiration, groundwater abstraction, and agricultural return flow. A multiple linear regression (MLR) model was developed to define the functional relationship between irrigation costs and groundwater levels. The model showed that average groundwater level during the major irrigation period (January-April) decreased by 0.15-2.01 m due to an increase in temperature of 1-5°C, which increased irrigation costs by 0.05-0.54 thousand Bangladesh Taka (BDT) per hector.