Impacts of irrigated agricultural land expansion on groundwater security in Mithapukur Upazila, Bangladesh

The rapid expansion of groundwater-based irrigation has transformed agricultural productivity in Bangladesh, yet it has also intensified pressure on subsurface water resources. This study examined the impacts of irrigated agrarian land expansion on groundwater security in Mithapukur Upazila, Rangpur District, Bangladesh, an agriculturally intensive region characterized by dry-season Boro rice cultivation and limited surface-water availability. High-resolution land use maps derived from Orthorectified and Sentinel-2 imagery of 2000, 2010, and 2023 were combined with long-term groundwater level data from the Bangladesh Water Development Board (BWDB) to analyze spatiotemporal irrigation patterns and aquifer responses. Spearman’s rank correlation coefficient (ρ) was used to examine the relationship between irrigated area and groundwater level, while Root Mean Square Error (RMSE) was used to evaluate model prediction accuracy. Results indicate that the irrigated area increased from 269.57 km2 in 2000 to 318.97 km2 in 2023, while groundwater levels declined from 4.25 m to 5.48 m below the surface. Statistical analysis revealed a strong positive correlation (ρ = 0.879) between irrigation expansion and groundwater depletion, primarily driven by increased groundwater withdrawals, with limited surface water availability intensifying reliance on groundwater resources. These findings highlighted the urgent need for integrated water management strategies, including regulated pumping, adoption of water-efficient irrigation practices, and coordinated use of seasonal surface water for irrigation, combined with groundwater abstraction during dry periods, to safeguard both agricultural productivity and aquifer sustainability.